Campbell Biology Ch 1-18 Final Study Guide Exam questions with complete solutions., Exams of Biology

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Campbell Biology Ch 1-18 Final Study

Guide Exam questions with complete

solutions

covalent bond - correct answer>> the sharing of a pair of valence electrons by two atoms single bond - correct answer>> one pair of shared electrons (H-H) double bond - correct answer>> two pairs of shared electrons (O=O) nonpolar covalent bond - correct answer>> equally shared electrons in covalent bond with two atoms of the same element because the two atoms have the same electronegativity (O2, H2) polar covalent - correct answer>> atom is bonded to more electronegative atom causing unequal sharing of electrons ions - correct answer>> An atom or group of atoms that has gained or lost one or more electrons, thus acquiring a charge ionic bond - correct answer>> any two ions of opposite charge, no transfer required cation - correct answer>> a positively charged atom anion - correct answer>> a negatively charged ion weak chemical bonds - correct answer>> hydrogen bonds and can der Waals hydrogen bond - correct answer>> the attraction to an electronegative atom (N , O)

van der Waals interactions - correct answer>> weak attractions between molecules that result from transient local partial charges hydrogen resulting from polar covalent bonds - correct answer>> Oxygen is more electronegative than Hydrogen so the shared electrons spend more time closer to Oxygen, making Oxygen a partial negative charge and Hydrogen partial positive charge SPONCH - correct answer>> sulfur, phosphorus, nitrogen, carbon, hydrogen describe the chemical makeup of organisms in terms of what is essential for life - correct answer>> acid - correct answer>> a substance that increases the hydrogen ion [H+] concentration of a solution (HCl) base - correct answer>> a substance that reduces the hydrogen ion concentration of a solution (NaOH) [base->OH-] pH - correct answer>> a measure of hydrogen ion concentration equal to -log[H+] and ranging in value from 0 to 14 how pH affects the processes of life - correct answer>> key chemical functions groups that affect the function of biological molecules - correct answer>> functional group - correct answer>> a specific configuration of atoms commonly attached to the carbon skeletons of organic molecules and involved in chemical reactions explanation of the properties of functional groups in terms of polarity, charge, and hydrophobicity - correct answer>> polarity - correct answer>> molecule has both a positively and negatively charged end

hydrophobicity - correct answer>> the physical property of a molecule (known as a hydrophobe) that is seemingly repelled from a mass of water. structure and function of simple carbohydrates - correct answer>> made of just one or two sugar molecules. They are the quickest source of energy, as they are very rapidly digested (Ex: glucose) structure and function of complex carbohydrates - correct answer>> made up of sugar molecules that are strung together in long, complex chains, then turned to glucose in the body to use for energy. (Found in foods such as peas, beans, whole grains, and vegetables) carbohydrate - correct answer>> a sugar (monosaccharide) or one of its dimers (disaccharides) or polymers (polysaccharides) three main types of lipids - correct answer>> triglycerides (fats), steroids, and phospolipids lipid - correct answer>> Any of a group of large biological molecules, including fats, phospholipids, and steroids, that mix poorly, if at all, with water. phospolipid - correct answer>> A lipid made up of glycerol joined to two fatty acids and a phosphate group. The hydrocarbon chains of the fatty acids act as nonpolar, hydrophobic tails, while the rest of the molecule acts as a polar, hydrophilic head. Phospholipids form bilayers that function as biological membranes. triglyceride - correct answer>> A lipid consisting of three fatty acids linked to one glycerol molecule; also called a fat steroid - correct answer>> A type of lipid characterized by a carbon skeleton consisting of four fused rings with various chemical groups attached. saturated fat - correct answer>> A fatty acid in which all carbons in the hydrocarbon tail are connected by single bonds, thus maximizing the number of hydrogen atoms that are attached to the carbon skeleton.

unsaturated fat - correct answer>> A fatty acid that has one or more double bonds between carbons in the hydrocarbon tail. Such bonding reduces the number of hydrogen atoms attached to the carbon skeleton. main function of proteins - correct answer>> act as a structural component of cells and tissues made of many amino acids structures of amino acids and proteins - correct answer>> protein - correct answer>> a biologically functional molecule consisting of one or more polypeptides folded and coiled into a specific 3D structure amino acid - correct answer>> an organic molecule both a carboxyl and an amino group that serve as monomers of polypeptides chemical properties of an amino acid based on the structure of it's R group - correct answer>> a central carbon (also called the alpha carbon) bonded to a hydrogen, a carboxyl group, an amino group, a unique side chain or R-group R group - correct answer>> An abbreviation for any group in which a carbon or hydrogen atom is attached to the rest of the molecule. Sometimes used more loosely, to include other elements such as halogens, oxygen, or nitrogen. identify the component molecules of nucleotides - correct answer>> five carbon sugar phosphate molecule nitrogen-containing base compare and contrast structures of DNA and RNA, and their component nucleotides - correct answer>> DNA : deoxyribose (sugar), nucleotide bases, phosphate group RNA : ribose (sugar), nucleotide bases, phosphate group

Nucleotide bases can be synthesized with both purines and pyrimidines. For both DNA and RNA, purines are adenine and guanine. pyrimidines for DNA are thymine and cytosine whereas for RNA it's cytosine and uracil nucleotides - correct answer>> the building block of a nucleic acid, consisting of a 5-carbon sugar covalently bonded to a nitrogenous base and one or more phosphate groups DNA - correct answer>> a nucleic acid molecule, double-stranded helix, in which each polynucleotide strand has nucleotide monomers with a deoxyribose sugar and the nitrogenous bases adenine (A), cytosin (C), guanine (G), and thymine (T); capable of being replicated and determining the inherited structure of a cell's protein RNA - correct answer>> a type of nucleic acid consisting of a polynucleotide made up of nucleotide monomers with a ribose sugar and the nitrogenous bases adenine (A), cytosine (C), guanine (G), and uracil (U); usually single-standed; functions in protein synthesis, in gene regulation, and as the genome of some viruses determine the complementary sequence in nucleotide sequences - correct answer>> complementary sequence - correct answer>> two DNA/RNA sequences aligned antiparallel to each other making the nucleotide bases complementary to each other function of the nucleus - correct answer>> organelle of a eukaryotic cell that stores the cell's hereditary material, or DNA, in the form of chromosomes, made up of chromatin, and it coordinates the cell's activities, which include growth, intermediary metabolism, protein synthesis, and reproduction (cell division) chromosome structure and function - correct answer>> a cellular structure, located in the nucleus, made of one DNA molecule and associated protein molecules ribosome structure and function - correct answer>> assembled in the nucleolus; a complex of rRNA and protein molecules that functions as a site of protein synthesis in the cytoplasm

endomembrane system - correct answer>> the collection of membranes inside and surrounding a eukaryotic cell, related either through direct physical contact or by the transfer of membranous vesicles; includes the plasma membrane, the nuclear envelope, the smooth and rough ER, the Golgi apparatus, lysosomes, vesicles, and vacuoles plasma membrane - correct answer>> the membrane at the boundary of every cell that acts as selective barrier, regulating the cell's chemical composition nuclear envelop - correct answer>> In a eukaryotic cell, the double membrane that surrounds the nucleus, perforated with pores that regulate traffic with the cytoplasm. The outer membrane is continuous with the endoplasmic reticulum smooth ER - correct answer>> portion of the endoplasmic reticulum that is free of ribosomes rough ER - correct answer>> portion of the endoplasmic reticulum with ribosomes attached Golgi apparatus - correct answer>> organelle with stacks of flat membranous sacs that modify, store, and route products of the ER and synthesize some products, notably noncellulose carbohydrates; located in eukaryotic cells lysosomes - correct answer>> a membrane-enclosed sac of hydrolytic enzymes found in the cytoplasm of animal cells and some protists vacuoles - correct answer>> a membrane-bounded vesicle whose specialized function varies in different kinds of cells function of the mitochondria - correct answer>> organelle in eukaryotic cells; site of cellular respiration by using oxygen to break down organic molecules and synthesize ATP function of the chloroplast - correct answer>> organelle in plants and photosynthetic protists; absorbs sunlight and uses it to drive the synthesis or organic compounds from carbon dioxide and water

cytoskeleton - correct answer>> a network of microtubules, microfilaments, and intermediate filaments that extend throughout the cytoplasm and serve a variety of mechanical, transport, and signaling functions structure of microtubule - correct answer>> a hollow rod composed of tubulin proteins that makes up part of the cytoskeleton in all eukaryotic cells; found in cilia and flagella function of microtubule - correct answer>> chromosomes are attached to microtubules at their kinetochores to pull them to opposite pole structure and function of the microfilament - correct answer>> a cable composed of actin proteins in the cytoplasm of almost every eukaryotic cell, making up part of the cytoskeleton and acting alone or with myosin to cause cell contraction (aka actin filament) function and structure of intermediate filaments - correct answer>> a component of the cytoskeleton that includes filaments intermediate in size between microtubules and microfilaments Fluid Mosaic model - correct answer>> model of cell membrane structure that envisions the membrane as a mosaic of protein molecules drifting laterally in a fluid bilayer of phospholipids selective permeability - correct answer>> a property of biological membranes that allows them to regulate the passage of substances across them how membrane structure results in selective permeability - correct answer>> external signals - correct answer>> responses - correct answer>> the change in a specific cellular activity brought about by a transduced signal from outside the cell describe how external signals are converted to responses within cells - correct answer>>

mitosis - correct answer>> a process of nuclear division divided into five stages: prophase, prometaphase, metaphase, anaphase, and telophase. It conserves chromosome number by allocating replicated chromosomes equally to each of the daughter nuclei explain how mitosis results in genetically identical cells (use chromosome, chromatin, chromatid) - correct answer>> Include supercoiling of chromosomes, attachment of spindle microtubules, splitting of centromeres, movement of sister chromosomes to opposite poles and breakage and reformation of nuclear membranes. 1.During Prophase, the mitotic spindle (made from microtubules) starts growing (going from pole to pole).Chromatin coil up to form distinct chromosomes. (Each chromosome contains two identical sister chromatids, attached to each other at the centromere region.) The nuclear envelope starts breaking down. 2.During Metaphase, each chromosome attaches to two spindle microtubules (one going to each pole) at the centromere region, so that they line up at the (virtual) equator of the cell. The mitotic spindle is fully developed: some microtubules are attached to chromosomes and reach to the equator, whilst others go from pole to pole. 3.During Anaphase, the spindle microtubules pull the sister chromatids to opposite poles (each sister chromatid becomes one new chromosome of the daughter cell). 4.During Telophase, each sister chromatid reaches its pole (becoming a chromosome). The nuclear envelope starts to reform. Spindle microtubles deteriorate. Cytokinesis (division of the cytoplasm) takes place. A useful mnemonic for remembering all the phases in the correct order is "I Passed My Algebra Test" or "Interphase Prophase Metaphase Anaphase Telophase." If this does not help you, try thinking of the simple acronym "P-MAT," or learning the word "prometanelo." interphase - correct answer>> period in cell cycle when the cell is not dividing; the cellular metabolic activity is high, chromosomes and organelles are duplicated, and cell size may increase; 90% of cell cycle mitotic (M) phase - correct answer>> phase of the cell cycle that includes mitosis and cytokinesis phases of the cell cycle - correct answer>> Interphase: chromatin duplicate, Prophase: nucleolus disappears, mitotic spindle begins to form, chromosomes visible with light microscope, Metaphase: chromosomes aligned at metaphase plate, Anaphase: chromosomes pulled apart at the kinetochore by microtubules, Telophase: daughter nuclei are forming and cytokinesis has begun

first law of thermodynamics - correct answer>> Conservation of energy: Energy can be transferred and transformed, but can't be created or destroyed second law of thermodynamics - correct answer>> every energy transfer or transformation increases the entropy of the universe; usable forms of energy are partly converted to heat how the two laws of thermodynamics relate to biological systems - correct answer>> Energy enters living systems as chemical energy (either food derived from other organisms or compounds formed by high energy processes such as geothermal energy) or light energy via photosynthesis. This energy is used to maintain the cellular environment (homeostasis), growth and replication. Although breaking down compounds yields energy, some is lost as heat, and more energy is lost as heat building the compounds up. G (free energy) - correct answer>> portion of a biological system's energy that can perform work when temperature and pressure are uniform throughout the system. Change of free energy of a system calculation: ΔG = ΔH − TΔS stability, capacity to do work, and spontaneous reactions related to Free Energy (G) - correct answer>> Free energy (Gibbs) is a minimum, and therefore systems with low delta G are more spontaneous i.e. they require less energy to drive a reaction or physical process forward. Systems with a negative GFE will be spontaneous, the more negative the more spontaneous and rapid the process will be. A high GFE would indicate that the system is stable and unlikely to change without external influence. The relationship of free energy to stability, work capacity, and spontaneous change is that it is unstable systems are rich in free energy, or G. They have a tendency to change spantaneously to more stable state , and it is possible to harness this " down hill" change to perform work. exergonic reaction (relate to G) - correct answer>> sponstaneous chemical reaction in which there is a net release of free energy endergonic reaction (relate to G) - correct answer>> nonspontaneous chemical reaction in which free energy is absorbed from the surroundings energy coupling of ATP hyrolysis - correct answer>> the use of energy released from an exergonic reaction to drive an endergonic reaction

enzymes - correct answer>> macromolecule serving as a catalyst, a chemical agent that increases the rate of a reaction without being consumed by the reaction; usually proteins how enzymes speed up metabolic reactions (orienting substrates, straining bonds in substrate, rearranging electron configuration in substrate bonds, providing a favorable microenvironment for a reaction) - correct answer>> redox reaction - correct answer>> a chemical reaction involving the complete or partial transfer of one or more electrons from one reactant to another (reduction-oxidation reaction) how redox reactions of catabolic pathways yield energy by oxidizing organic fuels - correct answer>> glycolysis - correct answer>> a series of reactions that ultimately splits glucose into pyruvate. It's the starting point for fermentation or cellular respiration oxidation of pyruvate - correct answer>> The acetyl group is attached to coenzyme A, a carrier formed from nucleotides, and the resulting molecule, Acetyl-CoA, is transported to the citric acid cycle, which also occurs in the mitochondrial matrix. The overall reaction for pyruvate oxidation is: Pyruvate + CoA + NAD+ → Acetyl-CoA + NADH + H+ + CO2. citric acid cycle - correct answer>> A chemical cycle involving eight steps that completes the metabolic breakdown of glucose molecules begun in glycolysis by oxidizing acetyl CoA (derived from pyruvate) to carbon dioxide; occurs within the mitochondrion in eukaryotic cells and in the cytosol of prokaryotes; together with pyruvate oxidation, the second major stage in cellular respiration process by which further oxidation occurs in the citric acid cycle - correct answer>> oxidative phosphorylation - correct answer>> The production of ATP using energy derived from the redox reactions of an electron transport chain; 3rd major stage of cellular respiration steps of oxidative phosphorylation - correct answer>> 1. The electron transport chain: no ATP here, just lots of electrons being transported.

2. Chemiosmosis: a gradient of protons (H+) drive the enzyme ATP synthase to make ATP

describe chloroplast structure, list all membranes and compartments - correct answer>> A double membrane surrounding a dense fluid called the stroma and elaborate membrane system called thylakoids, enclosing the thylakoids space. Thylakoid sacs may be stacked to form grana. Chlorophyll is embedded in the thylakoid membrane. photosynthesis - correct answer>> the conversion of light energy to chemical energy that is stored in sugars or other organic compounds; occurs in plants, algae, and certain prokaryotes photosynthesis equation - correct answer>> 6CO2 + 6H2O --> C6H12O6 + 6O photosystem - correct answer>> A light-capturing unit located in the thylakoid membrane of the chloroplast or in the membrane of some prokaryotes, consisting of a reaction-center complex surrounded by numerous light-harvesting complexes. There's two types of photosystems that absorb light best at different wavelengths list components of a photosystem, explain the function of each component - correct answer>> Located in the thylakoid membrane, contain a number of light-harvesting complexes and a reaction center complex, which is a protein complex with two special chlorophyll a molecules and a primary electron acceptor; The chlorophyll a molecule at the reaction center of photosystem II (PSII) is called P680, after the wavelength of the light (680 nm) it absorbs best. At the reaction center of photosystem I (PSI) is a chlorophyll a molecule called P700. photosystem II - correct answer>> One of the two light-capturing units in a chloroplast's thylakoid membrane or in the membrane of some prokaryotes; it has two molecules of P680 chlorophyll(a) at its reaction center electron transport chain - correct answer>> A sequence of electron carrier molecules (membrane proteins) that shuttle electrons down a series of redox reactions that release energy used to make ATP photosystem I - correct answer>> A light-capturing unit in a chloroplast's thylakoid membrane or in the membrane of some prokaryotes; it has two molecules of P700 chlorophyll(a) at its reaction center movement of electrons in linear electron flow through PSII, electron transport chain, and PSI - correct answer>> Linear electron flow is the electrons that pass through the two photosystems from water to

NADP+. Cyclic electron flow are the electrons excited from P700 in PSI are passed from Fd to the cytochrome complex and back to P700. linear electron flow - correct answer>> A route of electron flow during the light reactions of photosynthesis that involves both photosystems (I and II) and produces ATP, NADPH, and O2. The net electron flow is from H2O to NADP+ light reactions - correct answer>> The first two major stages in photosynthesis (preceding the Calvin Cycle). These reactions, which occur on the thylakoid membranes of the chloroplast or on membranes of certain prokaryotes, cnvert solar energy to the chemical energy of ATP and NADPH, releasing oxygen in the process chemiosmosis - correct answer>> An energy-coupling mechanism that uses energy stored in the form of a hydrogen ion gradient across a membrane to drive cellular work, such as the synthesis of ATP. Under aerobic conditions, most ATP synthesis in cells occurs by chemiosmosis oxidative phosphorylation - correct answer>> (Mitochondria) The production of ATP using energy derived from the redox reactions of an electron transport chain; the third major stage of cellular respiration photophosphorylation - correct answer>> (Chloroplast) The process of generating ATP from ADP and phospate by means of chemiosmosis, using a proton-motive force generated across the thylakoid membrane of the chloroplast or the membrane of certain prokaryotes during the light reactions of photosynthesis state the function of each of the three phases of the calvin cycle - correct answer>> 3. Carbon fixation: 3 RuBP + 3 CO2 => 6 3-Phosphoglycerate. [atmospheric CO2 becomes covalently bonded to RuBP with enzyme Carboxylase, Oxygenase]

2. Reduction: Reduction: each molecule of 3-phosphoglycerate gets an additional phosphate group from ATP
3. Regeneration of CO2 acceptor: 5 molecules of G3P into 3 molecules of RuBP

calvin cycle - correct answer>> The second of two major stages in photosynthesis (following the light reactions), involving fixation of atmospheric CO2 and reduction of the fixed carbon into carbohydrate ATP and NADPH in calvin cycle - correct answer>> used to reduce 3-PGA into G3P; then ATP and NADH are converted to ADP and NADP+, respectively. photorespiration - correct answer>> A metabolic pathway that consumes oxygen and ATP, releases carbon dioxide, and decreases photosynthetic output. Occurs on hot, dry, bright days, when stomata close and the O2/CO2 ratio in the leaf increases, favoring the binding of O2 rather than CO2 by rubisco rubisco - correct answer>> RuBP; the enzyme that normally catalyzes the first step of the Calvin Cycle (the addition of CO2 to RuBP). When excess O2 is present or CO2 levels are low, rubisco can bind oxygen, resulting in photorespiration [ribulose biphosphate carboxylase-oxygenase] two important photosynthetic adaptations that minimize photorespiration - correct answer>> C4 plants and CAM plants are the two most important photosynthetic adaptations that minimize photorespiration. In C4 plants, CO2 is first added to a three-carbon compound, PEP, with the aid of an enzyme (PEP carboxylase) that has a high affinity for CO2. The resulting four-carbon compound formed in the mesophyll cells of the leaf is transported to bundle-sheath cells tightly packed around the veins of the leaf. The compound is broken down to release CO2, which rubisco then fixes into the Calvin cycle. In CAM plants, they break down the compounds down to release CO2 during daylight so that the Calvin cycle can proceed. The process of succulent plants close their stomata during the day to prevent water loss, but open at night to take up CO2 and incorporate it into a variety of organic acids. The CAM pathway does not structurally separate carbon fixation from the Calvin cycle meiosis - correct answer>> cell division in sexually reproducing organisms having two rounds of cell division but only one round of DNA replication resulting in cells with half the number of chromosome sets as the original cell meiosis 1 - correct answer>> parent cell with chromosomes is divided into two daughter cells with chromosomes meiosis 2 - correct answer>> two daughter cells go through division resulting in four daughter cells with chromatids

Mendel's two laws of inheritance - correct answer>> law of segregation, law of independent assortment monohybrid cross - correct answer>> A cross between two organisms that are heterozygous for the character being followed (or the self-pollination of a heterozygous plant). monohybrid - correct answer>> An organism that is heterozygous with respect to a single gene of interest. All the offspring from a cross between parents homozygous for different alleles are monohybrids. [parents of genotypes AA and aa produce a monohybrid of genotype Aa] law of segregation - correct answer>> Mendel's first law, stating that the two alleles in a pair segregate (separate from each other) into different gametes during gamete formation dihybrid cross - correct answer>> A cross between two organisms that are each heterozygous for both of the characters being followed (or the self-pollination of a plant that is heterozygous for both characters). dihybrid - correct answer>> An organism that is heterozygous with respect to two genes of interest. All the offspring from a cross between parents doubly homozygous for different alleles are dihybrids [parents of genotypes AABB and aabb produce a dihybrid of genotype AaBb] law of independent assortment - correct answer>> Mendel's second law, stating that each pair of alleles segregates, or assorts, independently of each other pair during gamete formation; applies when genes for two characters are located on different pairs of homologous chromosomes or when they are far enough apart on the same chromosome to behave as though they are on different chromosomes punnet square - correct answer>> A diagram used in the study of inheritance to show the predicted genotypic results of random fertilization in genetic crosses between individuals of known genotype laws of probability - correct answer>> expresses the total probability of an outcome which can be realized via several distinct events segregation ratios - correct answer>> calculations genetics crosses using Punnet squares or the laws of probability

complete dominance - correct answer>> The situation in which the phenotypes of the heterozygote and dominant homozygote are indistinguishable incomplete dominance - correct answer>> The situation in which the phenotype of heterozygotes is intermediate between the phenotypes of individuals homozygous for either allele [redxwhite=pink] codominance - correct answer>> The situation in which the phenotypes of both alleles are exhibited in the heterozygote because both alleles affect the phenotype in separate, distinguishable ways [all whitexall black= black sections, white sections] multiple alleles - correct answer>> a series of three or more alternative or allelic forms of a gene, only two of which can exist in any normal, diploid individual pleiotropy - correct answer>> a single gene having multiple effects epistasis - correct answer>> A type of gene interaction in which the phenotypic expression of one gene alters that of another independently inherited gene polygenic inheritance - correct answer>> An additive effect of two or more genes on a single phenotypic character sex-linked gene - correct answer>> A gene located on either sex chromosome. Most sex-linked genes are on the X chromosome and show distinctive patterns of inheritance; there are very few genes on the Y chromosome effect of sex linkage - correct answer>> located on the sex chromosomes; their expression and inheritance patterns differ between males and females. Females-XX, Males-XY; men inherit their X chromosome from mom and since most diseases are located on the X chromosome, men are more likely to get certain disorders or diseases than women Federick Griffith - correct answer>> experimented on pneumonia bacteria and mice

Oswald Avery, Maclyn McCarty, Colin MacLeod - correct answer>> DNA is the substance that causes bacterial transformation, in an era when it had been widely believed that it was proteins that served the function of carrying genetic information Alfred Hershey and Martha Chase - correct answer>> • In 1952, Alfred Hershey and Martha Chase performed experiments showing that DNA is the genetic material of a phage known as T

• To determine this, they designed an experiment showing that only one of the two components of T (DNA or protein) enters an E. coli cell during infection.
• They concluded that the injected DNA of the phage provides the genetic information. Erwin Chargaff - correct answer>> Analyzed the base content of DNA and found that the amount of adenine equaled and amount of thymine and the amount of guanine equals the amount of cytosine. Watson and Crick deduced the structure of DNA, describe evidence used. Explain significance of Rosalind Franklin's research - correct answer>> They used Rosalind Franklin's experiments with X-ray and came up with the concept of the double helix structure of DNA - correct answer>> Made out of two strands forming a double helix with the attachments of the sugar-phosphate backbones on the outside. There are also hydrogen bonds between the nitrogenous bases. Two H-bonds for A & T while G & C had three bonds. base-pairing rule and significance - correct answer>> There were also base pairings by following Chargaff's rule. There are also hydrogen bonds between the nitrogenous bases. Two H-bonds for A & T while G & C had three bonds. (A+T) (C+G) semiconservative model of replication - correct answer>> Type of DNA replication in which the replicated double helix consists of one old strand, derived from the parental molecule, and one newly made strand significance of the experiments of Matthew Meselson and Franklin Stahl - correct answer>> Experiments by Matthew Meselson and Franklin Stahl supported the semiconservative model.
• They labeled the nucleotides of the old strands with a heavy isotope of nitrogen, while any new nucleotides were labeled with a lighter isotope.

• The first replication produced a band of hybrid DNA, eliminating the conservative model.
• A second replication produced both light and hybrid DNA, eliminating the dispersive model and supporting the semiconservative model. DNA replication - correct answer>> The process by which a DNA molecule is copied (DNA synthesis) process of DNA replication, include the role of the origins of replication and replication forks - correct answer>> 1.) In the beginning, a site called origins of replication has short stretches of DNA that have specific sequence of nucleotides. 2.) Proteins that initiate DNA replication separates the two strands which opens a replication bubble. At each ends of the bubble there is the replication fork. 3.) The enzyme helicase untwists the double helix at the replication forks. 4.) Once separated single-strand binding proteins bind to the unpaired DNA allowing stabilization. 5.) The topoisomerase relieves the strain from the untwisting of the double helix. 6.) Primase starts an RNA chain from a single RNA nucleotide and adds more RNA nucleotides. 7.) In E.coli, DNA pol III adds a DNA nucleotide to the RNA primer and continues adding till it reaches to the RNA primer to the right where a Okazaki fragment is formed. 8.) DNA pol I comes in and replaces the RNA nucleotides with DNA nucleotides. 9.) Lastly, DNA ligase comes in and joins the sugar-phosphate backbones of all the Okazaki fragments into a continuous DNA strand. DNA polymerase - correct answer>> An enzyme that catalyzes the elongation of new DNA (ex: at a replication fork) by the addition of nucleotides to the 3' end of an existing chain. leading strand - correct answer>> The new complementary DNA strand synthesized continuously along the template strand toward the replication fork in the mandatory 5' to 3' direction lagging strand - correct answer>> A discontinuously synthesized DNA strand that elongates by means of OKazaki fragments, each synthesized in a 5'->3' direction away from the replication fork Explain how the lagging strand is synthesized even though DNA polymerase can add nucleotides only to the 3' end - correct answer>> The lagging strand is synthesized in a series of short fragments called okazaki fragments.

Each okazaki fragment is bonded covalently by DNA ligase to the others to create a continuous strand. Each fragment requires a primer. These small fragments are generated by the polymerase making a small 5' to 3' fragment inside the replication bubble as it opens. Then all the little fragments are joined together. significance of Okazaki fragments - correct answer>> short segment of DNA synthesized away from the replication fork on a template strand during DNA replication, many segments are joined together to make up the lagging strand of newly synthesized DNA DNA ligase - correct answer>> A linking enzyme essential for DNA replication; catalyzes the covalent bonding of the 3' end of one DNA fragment (Okazaki fragment) to the 5' end of another DNA fragment (growing DNA chain) primer - correct answer>> A short stretch of RNA with a free 3' end, bound by complementary base pairing to the template strand and elongated with DNA nucleotides during DNA replication DNA primase - correct answer>> AN enzyme that joins RNA nucleotides to make a primer during DNA replication, using the parental DNA strand as a template helicase - correct answer>> An enzyme that untwists the double helix of DNA at replication forks, separating the two strands and making them available as template strands topoisomerase - correct answer>> A protein that breaks, swivels, and rejoins DNA strands. During DNA replication, topoisomerase helps to relieve strain in the double helix ahead of the replication fork single-strand binding proteins - correct answer>> A protein that binds to the unpaired DNA strands during DNA replication, stabilizing them and holding them apart while they serve as templates for the synthesis of the complementary strands of DNA antiparallel - correct answer>> Referring to the arrangement of the sugar-phosphate backbones in a DNA double helix (they run in opposite 5'->3' directions)

Explain why continuous synthesis of both DNA strands is not possible - correct answer>> DNA can only be replicated from the 5' to 3' end, so they go in opposite directions mismatch repair enzyme - correct answer>> removes and replaces incorrectly paired nucleotides nuclease - correct answer>> Enzyme that cuts DNA or RNA, either removing one or a few bases or hydrolyzing the DNA or RNA completely into its component nucleotides function of the telomere - correct answer>> The tandemly repetitive DNA at the end of a eukaryotic chromosome's DNA molecule. Telomeres protect the organism's genes from being eroded during successive rounds of replication chromatin - correct answer>> The complex of DNA and proteins that makes up eukaryotic chromosomes. When the cell is not dividing, chromatin exists in its dispersed form, as a mass of very long, thin fibers that are not visible with a light microscope describe how the packing of chromatin changes during the course of the cell cycle - correct answer>> -In interphase the chromatin is highly extended -As a cell prepares for mitosis, its chromatin coils and folds up (condenses), eventually forming a characteristic number of short thick metaphase chromosomes that are distinguishable heterochromatin - correct answer>> eukaryotic chromatin that remains highly compacted during interphase and is generally not transcribed euchromatin - correct answer>> the less condensed form of eukaryotic chromatin that is available for transcription how RNA differs from DNA - correct answer>> (1) the sugar in RNA is ribose not dioxyribose; (2) RNA is generally single-stranded and not double-stranded; and (3) RNA contains uracil in place of thymine explain how information flows from gene to protein - correct answer>> The sequence of nucleotides in DNA holds the instructions for making proteins but must first be transcribed into RNA nucleotides. RNA

then takes the message out of the nucleus to the ribosomes, the site of protein synthesis. At the ribosomes, RNA is translated into amino acids to form a polypeptide that later folds to become a protein. transcription - correct answer>> The synthesis of RNA using a DNA template translation - correct answer>> The synthesis of a polypeptide using the genetic information encoded in an mRNA molecule. There is a change of "language" from nucleotides to amino acids translation and transcription in eukaryotic vs bacteria - correct answer>> Eukaryotic: discontinuous process because transcription occurs in the nucleus and translation occurs in the cytoplasm Bacteria: continuous because transcription and translation both occur in the cytoplasm codon - correct answer>> 3-nucleotide sequence of DNA or mRNA that specifies a particular amino acid or termination signal; the basic unit of the genetic code explain the relationship between the linear sequence of codons on mRNA and the linear sequence of amino acids in a polypeptide - correct answer>> The linear sequence of the codon on the mRNA strand will code for some amino acid and thus a protein will be created. mRNA - correct answer>> (messenger RNA) synthesized using a DNA template, that attaches to ribosomes in the cytoplasm and specifies the primary structure of a protein. Eukaryotes: primary RNA transcript must undergo RNA processing to become mRNA explain what it means to say that the genetic code is redundant and unambiguous - correct answer>> The code is redundant - more than one codon per amino acid, but not ambiguous - no codon specifies more than one amino acid reading frame in translation - correct answer>> on an mRNA, the triplet grouping of ribonucleotides used by the translation machinery during polypeptide synthesis

explain how RNA polymerase recognizes where transcription should begin - correct answer>> RNA polymerase recognizes where transcription should begin by attaching and initiating at the sequence known as a promoter. RNA polymerase does not need a primer. The RNA polymerase stops transcription when it reaches the terminator, or the sequence coding for "stop". The transcription unit is the stretch of DNA that is transcribed into RNA promoter - correct answer>> A specific nucleotide sequence in the DNA of a gene that binds RNA polymerase, positioning it to start transcribing RNA at the appropriate place terminator - correct answer>> In bacteria, a sequence of nucleotides in DNA that marks the end of a gene and signals RNA polmerase to release the newly made RNA molecule and detach from teh DNA transcription unit - correct answer>> region of DNA that's transcribed into an RNA molecule transcription vs translation - correct answer>> Transcription is DNA into RNA which is mediated by RNA polymerase, this occurs in the nucleus , has 3 stages, and transcribed in 5'-3' direction. Translation is RNA into protein, occurs in the cytoplasm, mRNA is read in a 5'-3' direction, has three stages, and polypeptide is built N-terminal to C-terminal end. Explain how RNA is modified after transcription in eukaryotic cells - correct answer>> A poly-a tail is added to the 3' end (adenine) and a 5' cap of modified guanine is added to the 5'end tRNA structure and function - correct answer>> (transfer RNA) an RNA molecule that functions as a translator between nucleic acid and protein languages by carrying specific amino acids to the ribosome, where they recognize the appropriate codons in the mRNA significance of wobble - correct answer>> flexibility in the base-pairing rules in which the nucleotide at the 5' end of a tRNA anticodon can form hydrogen bonds with more than one kind of base in the third position (3' end) of a codon Explain how tRNA is joined to the appropriate amino acid - correct answer>> tRNA is joined to the appropriate amino acid by use of a family of enzymes called aminoacyl-tRNA synthetases. the active site of these synthetases fit only a specific combination of tRNA and amino acid.

Ribosomes structure and function - correct answer>> Structure Large with 60% rRNA and 40% protein Two subunits found separately unless actively translating Groove for mRNA P-, A-, and E- sites for tRNA binding Function Clamp onto mRNA at start codon Align tRNAs Form peptide bonds Move codon-by-codon along mRNA translation process (include initiation, elongation, and termination). Explain which enzymes, protein factors, and energy sources are needed for each stage - correct answer>> Ribosome Association and Initiation of Translation Small subunit binds to mRNA leader or 5' cap and tRNAmet in P-site Large subunit then binds Protein initiation factors and energy from GTP are required Elongation of the Polypeptide Chain Next tRNA binds codon under A-site; uses elongation factors and GTP Peptide bond formed Growing polypeptide chain bound to tRNA in A-site Translocation = ribosome shifts over one codon Termination of Translation Release factor binds stop codon (UAA, UAG, or UGA) under A-site Water molecule added (hydrolysis) New polypeptide released from last tRNA

primary structure - correct answer>> the linear sequence of amino acids in the polypeptide chain; held together by covalent bonds such as peptide bonds, which are made during the process of protein biosynthesis or translation Explain what determines the primary structure of a protein and describe how a polypeptide must be modified before it becomes fully functional - correct answer>> DNA determines primary structure, and amino acid sequence is the primary structure; The primary structure of the protein is determined by the sequence of DNA. Every three nucleotides (sub-unit/building blocks of DNA) codes for a particular amino acid. The sequence of amino acids (which are sub-units/building blocks of protein) in a protein structure is the primary structure of the protein. Describe what determines whether a ribosome will be free in the cytosol or attached to the rough ER - correct answer>> Membrane-bound ribosomes make endomembrane and secreted proteins Amino-terminal signal peptide is bound by signal-peptide recognition particle Complex binds to rough ER Signal peptide is removed from finished protein point mutations - correct answer>> change in a single nucleotide pair of a gene base-pair substituitions (example and significance of change) - correct answer>> a mutation involving a nucleotide being replaced with another base-pair insertions (example of significance) - correct answer>> a mutation involving the addition of one or more nucleotide pairs to a gene base-pair deletions - correct answer>> a mutational loss of one or more nucleotide pairs from a gene silent mutations - correct answer>> A nucleotide-pair substitution that has no observabe effect on the phenotype Ex: a mutation that results in a codon that codes for the same amino acid (harmless) missense mutations - correct answer>> A nucleotide-pair substitution resulting in a codon that codes for a different amino acid

nonsense mutations - correct answer>> A mutation that changes an amino acid codon to one of the three stop codons, resulting in a shorter and usually nonfunctional protein Explain why an insertion or deletion is more likely to be deleterious than a substitution - correct answer>> Insertion or deletion of nucleotides may alter the reading frame of the genetic message. A mutation called the framshift mutation occurs whenever the number of nuleotides inserted or deleted isn't a multiple of three. This will result in an extensive missense which makes the protein that is translated to be nonfunctional. differential gene expression - correct answer>> the expression of different sets of genes by cells with the same genome At what level is gene expression generally controlled? - correct answer>> At transcriptional level Involves DNA-binding proteins Coordinated by external signals Role of transcription initiation complex - correct answer>> Assembly of RNA pol. II and GTFs transcription initiation complex - correct answer>> The assembly of transcription factors and RNA polymerase bound to a promtoter control elements - correct answer>> segment of noncoding DNA that helps regulate transcription Explain how control elements influence transcription - correct answer>> Noncoding sequences where transcription factors bind May be close (proximal) or far away (distal) general transcription factors vs specific trancription factors - correct answer>> General transcription factors are proteins that help form the pre-initation complex responsible for the start of transcription Specific transcription factors can be a wide variety of proteins involved in modulation of transcription processes,

role of promoters - correct answer>> A specific nucleotide sequence in the DNA of a gene that binds RNA polymerase, positioning it to start transcribing RNA at the appropriate place enhancers - correct answer>> Segment of eukaryotic DNA containing multiple control elements, usually located far from the gene whose transcription it regulates activators - correct answer>> A protein that binds to DNA and stimulates gene transcription Prokaryote: activators bind in or near the promoter Eukaryote: activators bind to control elements in enhancers repressors - correct answer>> protein that inhibits gene transcription Prokaryotes: bind to the DNA in or near the promoter Eukaryotes: bind to control elements with enhancers, to activators, or to other proteins in a way that blocks activators from binding to DNA Explain how eukaryotic genes can be coordinately expressed (describe example) - correct answer>> Associated with specific regulatory DNA sequences or enhancers that are recognized by a single type of transcription factor that activates or represses a group of genes in synchrony heat shock response - series of proteins that help stabilize and repair Steroid hormone action - steroids activate protein receptors which activate genes Cellular differentiation the genes produce particular sets of proteins which go on and off