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BIOL 1406 exam 2 chapters 5-7 Collin
college
define macromolecules. name them - correct answer large molecules composed of thousands of covalently connected atoms define polymers? monomers - correct answer polymers- long molecule consisting of many similar building blocks monomers- small building-block molecules what is dehydration reaction - correct answer occurs when 2 monomers bond together through the loss of a water molecules hydrolysis - correct answer polymers are disassembled to monomers; reaction that is essentially the reverse of dehydration reaction what are carbohydrates? what is a monosaccharide? what is its use to a cell - correct answer carbs- serve as fuel and building material (1st thing body goes to) monosaccharide- simplest/single sugars; glucose is the most common what is the general molecular formula for a monosaccharide - correct answer CH2O what is a disaccharide? glycosidic linkage. know sucrose examples - correct answer disaccharide- formed when a dehydration and reaction joins 2 monosaccharides glycosidic linkage- covalent bond
what are polysaccharides? know starch, glycogen, cellulose, and chitin - correct answer polysaccharides- polymers of sugars (many), have storage and structural roles starch- plants store gluslose (bread, pasta rice, potatos) glycogen- animals store glucose cellulose- makes up the cell wall of plants chitin- found in the exoskeleton of arthropods how are polymers with glucose different from B glucose - correct answer polymers with a glucose are helical polymers with B are straight -form microfibrils, which form strong building materials for plants what compounds makes up the diverse groups, liquids - correct answer fats & oils phospholipids steroids waxes what are fats constructed of? what is an ester linkage? triacylglyerol? - correct answer fats- glycerol and fatty acids fatty acids- consists of a carboxyl group attached to a long carbon skeleton What are saturated fats? Unsaturated fats? What are the properties of each? Where are they found? Which are healthier? - correct answer satured fats- maximum number of hydrogen atom possible and no double bonds; fiybd ub bytter
what is the relationship between proteins and polypeptides - correct answer polypeptides- unbranched polymers build from the same set of 20 amino acids protein- biologically functions molecule that consists of one or more polypeptides what are amino acids? what is the significance of the R group? how many amino acids are there - correct answer amino acids= organic molecules with carboxyl and amino groups -R group- differ in their properties due to differing sides chains (cariable group) how many- 20 what is peptide bond? Significance of carboxyl and amino groups - correct answer amino acids are liked by these polypeptide is a polymer of amino acids each polypeptide has a unique linear sequence of amino acids what determines the function of a protein - correct answer shape -> structure -> function what are the 4 levels of protein structure? describe them. example - correct answer 1. primary structure of a protein is its unique sequence of amino acids
- secondary structure found in most proteins, consists of coids and fold int he polypeptide chain (H bonds)
- tertiary structure determined by interactions amoung various side chains (R groups)
- quaternary structure results when a protein consists of multiple polypeptide chains how is hemoglobin affected in sickle-cell disease - correct answer globular protein consisting of 4 polypeptides: 2 alpha and 2 beta chains
sickle-cell disease define denaturation? what factors cause it - correct answer loss of a protein natives structure -denautres protein is biologically inactive what role do chaperonins play - correct answer proteins molecules that assist the proper folding of other proteins how is X-ray crystallography used - correct answer determine proteins structure what are nucleic acids? what is nucleotide? what are its 3 parts - correct answer nucleic acid- genes are made of DNA, made of monomers called nucleoides store infor and help transmit it nucletoides- polynucleotide is made of monomers; consists of nitrogenous base, pentose sugar, one of mroe phosphate groupf what are the 2 types of nucleic acids? - correct answer deoxyribonucleic acid (DNA) -provides info for replication -will direct synthesis of proteins ribonucleic acid (RNA) describe the plasma membrane as a fluid mosaic - correct answer boundary that separates living cell from its surroundings who is credited the fluid mosaic models - correct answer S. J. Singer & G. Nicolson what did freeze-fracture studies reveal - correct answer splits a membrane along the middle of the phopholipid bilayer
what is the responsible for selective permeability - correct answer membrane structure what molecules are permeable through the membrane - correct answer small polar molecules describe transport proteins - correct answer allow passage hydrophilic substances across the membrane what are aquaporins - correct answer facilitate passage of water describe passive transport. diffusion. - correct answer substance across a membrane with no energy investment what is a concentration gradient - correct answer regions along which the density of chemical substance increases or decreases what is osmosis? what does it have to do with solute concentration - correct answer diffusion of water across a selectively permeable membrane; does this until concentration is equal on both sides describe tonicity - correct answer ability of a surrounding solution to cause a cell to gain or lose water define isotonic, hypertonic, and hypotonic solutions - correct answer isotonic- no net water movement across plasma membrane hypertonic- cell loses water hypotonic- cell gain water what is osmoregulation? the paramecium contractile vacuole - correct answer control of solute concentrations and water balance
paramecium- vacuole that acts as a pump describe plant cells that are turgid, flaccid - correct answer turgid- plant cell in a hypnotic solution sells until wall opposes uptake flaccid- no net movement of water into the cell; plant wilts what happens to a plant cell during plasmolysis - correct answer lose water; membrane pulls away from wall what is facility diffusion? role of channel proteins - correct answer transport proteins speed the passive movement of colecules across the plasma membrane provide corridors that allow a specific molecule or ion to corss the membrane what is the role of ion channels - correct answer open or close in response to a gated channels what is active transport? sodium-potassium pump example - correct answer uses energy to move solutes against their gradients allows cells to maintain concentration gradients that differ from surroundings define exocytosis & endocytosis - correct answer exocytosis- transport vesicles migrate to the membrane, fuse with it, release their contents endocytosis- cells take in macromolecules by forming vesicles from the plasma membrane what the the 3 types of endocytosis - correct answer phagocytosis -cellular eating pinocytosis
what does the plasma membrane do? what is it made up of - correct answer selective barrier that allows sufficient passage of oxygen, nutrients, and wste to service the volume of every cell; is a doulb layer of phosholipids what limits cells size - correct answer Fragility of cell membrane describe the nucleus, nuclear membrane, chromosomes, chromatin, nucleolus - correct answer nucleus- contains most of the cells genes, usually the most conspicuous organelle nuclear membrane- double membrane; each membrane consists of a lipid bilayer chromosomes- DNA is organized into discrete units chromatic- DNA and proteins of chromosomes nucleolus- locat4ed within the nucleus and is the site of RNA synthesis what do ribosomes do and where are they found - correct answer carry out protein synthesis in 2 locations; found in the cytosol (free ribosomes), outside of the endoplasmic reticulum or nuclear envelope (bound ribosomes) what are the components of the endomembrane system and what do they do - correct answer do- regulates protein traffic and performs metalbolic functions in the cell comonents: nuclear envelope, endoplasmic reticulum, golgi apparatus, lysosomes, vacuoles, plasma membrane what does the endoplasmic reticulum make - correct answer responsible for the assembly of many proteins how are the rough and smooth ER different - correct answer smooth- lacks ribosomes rough- studded with ribosomes
what are the functions of the smooth ER - correct answer synthesizes lipids, metabolized carbohydrates, detoxifies drugs & poisons, stores calcium ions what are the functions of the rough ER? transport cesicles - correct answer has bound ribosomes with secrete proteins bonded to carbs, distributes proteins surrounded by membranes, membrane factory for the cell describe the Golgi apparatus and its functions - correct answer function: shipping & receiving center ( modifies products of the ER, manufactures certain macromolecules, sorts and packages materials into transport vesicles describe: consists of flattened membranous sacs called cisternae what do lysosomes do? role in phagocytosis? - correct answer lysosomes- digestive compartments , can hydrolyze proteins, fats, polysaccharides, nucleci acids phagocytosis- food vacuole and digests the molecules, recycle cells own organelles and macromolecule describe vacuoles. food, contractile, and central - correct answer vacuoles- plant & fungal cells; derived from of reticulum and Golgi apparatus food vacuoles- formed by phagocytosis contractile vacuoles- found in many freshwater protists, pump excess water out of cells central vacuoles- found in many mature plant cells, hold organic compounds and water what is the relationship between the mitochondria and the chloroplasts - correct answer change energy from one form to another
fibers: microtubules (thickest), microfilaments (thinnest), intermediate filaments (diameters in a middle range) function of microtubules. centrosome, centrioles - correct answer microtubuels- hollow rods; functions: shaping cells, guiding movement of organelles, separate chromosomes during cell division describe cilia and flagella. how do they move? role of basal body, dynein protein - correct answer microtubules control the beating of cilia and flagella locomotor appendages of come cells; they differ in their beating patterns basal body- anchors cilium or flagellum (9+0) dynein- dirives the bending movements of cilium or flagellum What makes up microfilaments. Their role in cell. Muscles with myosin? In pseudopodia? Cytoplasmic streaming? - correct answer microfilaments- solid rods built as a twisted double chain; bear tension/ resisting pulling forces within the cell myosic- function in cellular motility contain this protein pseudopodia= cellular extensions cytoplasmic streaming- circular flow of cytoplasm within cells role of intermediate filaments - correct answer support cell shape and fix organelles in place know extracellular structures - correct answer cell wall of plants, extracellular matrix of animals cells, intercellular junctions role of cell wall. what organisms have it? what makes it up - correct answer plant cells only -prokaryotes, fungi and some protists also have thins
-cell wall, middle lamella, secondary cell wall role of plasmodesmata - correct answer channels between adjacent plant cells describe the ECM in animals. protein names - correct answer bind to receptor proteins in the plasma membrane (called integrins) function of EMS: support, adhesion, movement, regulation know 4 cell junctions. and their roles in plants and animals - correct answer plasmodesmata -perforate plant cell walls tight junctions -preventing leakage of extracellular fluid desmosomes -fasten cells together into strong sheets gap junctions -provide cytoplasmic channels between adjacent cells What are the bases in DNA & RNA? what is meant by complementary base pairing - correct answer In DNA, there are four different bases: adenine (A) and guanine (G) are the larger purines. Cytosine (C) and thymine (T) are the smaller pyrimidines. ... Three of these are the same as in DNA: adenine, guanine, and cytosine. RNA contains uracil (U) instead of thymine (T). pairing; DNA(=) A=T; G=C RNA(=) A=U; G=C
