Basic Concepts in Biochemistry and Cell Biology, Quizzes of Biology

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4 major elements that make up 96% of living

matter

1. Carbohydrates 2. Proteins 3. Nucleic Acids 4. Fats TERM 2

Nonpolar Covalent Bond

DEFINITION 2 When two atoms have similar electronegativities and electrons are shared equally; EVENLY SPACED MOLECULES- symmetrical TERM 3

Polar Covalent Bond

DEFINITION 3 If one atom has more electronegativity, the electrons are drawn to that nucleus. Electrons are not shared equally TERM 4

Ionic Bonds

DEFINITION 4 formed by the electrical attraction of + and - ions. Salts are ionically bonded compounds. TERM 5

Ions

DEFINITION 5 electrically charged compounds, when atoms lose or gain electrons

Cations

Postive ion TERM 7

Anion

DEFINITION 7 Negative ion TERM 8

Hydrogen Bonds

DEFINITION 8 attraction between the partial - end of one molecule and the partial positive H end of another molecule. Form between water molecules and are important in the structure of DNA and proteins. Polar molecules that form H-bonds with water are HYDROPHILIC. Nonpolar molecules such as hydrocarbons that interact with each other, but not with water, are HYDROPHOBIC. Sharing of an H atom TERM 9

van der Waals interactions

DEFINITION 9 attractions between nonpolar molecules. They result from random variations in electron distribution. Individual interactions are brief and weak, but summer over a large molecule, can be substantial. Weak interactions between molecules that result from localized charge fluctuations TERM 10

Hydrophobic Interaction

DEFINITION 10 interaction of nonpolar substances in the presence of polar substances (especially water)

Hydrophobic

non-polar substances in presence of water having an aversion to water; form droplets in water TERM 12

Hydrophilic

DEFINITION 12 having an affinity for water. Dominated by ionic or polar bonds TERM 13

Solute

DEFINITION 13 substance that is dissolved in solution TERM 14

Solvent

DEFINITION 14 the dissolving agent of a solution. Water is the most versatile solvent known TERM 15

Solution

DEFINITION 15 homogenous liquid mixture of 2 or more substances

Acid

a substance that increase the hydrogen ion concentration in a solution TERM 17

Base

DEFINITION 17 any substance that reduces the hydrogen ion concentration in a solution TERM 18

pH

DEFINITION 18 the negative logarithm (base 10) of the hydrogen ion concentration pH= -log[H+] or [H+]=10^(-pH) TERM 19

7 Functional groups found in organic

molecules

DEFINITION 19

1. Hydroxyl 2. Carbonyl 3. Carboxyl 4. Amino 5. Sulfhydryl 6. Phosphate 7. Methyl TERM 20

Hydroxyl Group

DEFINITION 20 (-OH) a hydrogen atom forms a polar covalent bond with an oxygen atom, which forms a polar covalent bond to the carbon skeleton. Hydroxyl groups increase the solubility of organic molecules. Organic compounds with hydroxyl groups are ALCOHOLS. (names typically end with -ol) H-bonds with water molecules, helping dissolve organic compounds like sugars

Carbonyl Group

(>CO) consists of an O atom joined to the carbon skeleton by a double bond. Aldehyde and Ketone. Isomers with aldehydes and those with ketones have different properties. Found in sugars. TERM 22

Aldehyde

DEFINITION 22 Carbonyl group is on the end of the skeleton. TERM 23

Ketone

DEFINITION 23 Carbonyl group within the carbon skeleton TERM 24

Carboxyl Group

DEFINITION 24 (-COOH) consists of a carbon atom with a double bond to an oxygen atom and a single bond to the oxygen atom of a hydroxyl group. Compounds with carboxyl are CARBOXYLIC ACIDS. This group acts as an acid because the combined electronegativities of the 2 adjacent O atoms increase the change of dissociation of H as an ion (H+) cells in the ionized form > charge of 1- TERM 25

Amino Group

DEFINITION 25 (-NH2) Organic compounds with amino groups are "amines." The amino group acts as a base because it can pick up a hydrogen ion from the solution. Amino acids, the building blocks of proteins, have amino and carboxyl groups. Acts as a BASE, can pick up H+. Ionized with a charge of 1+

Sulfhydryl

(-SH) Organic molecules with sulfhydryl groups are THIOLS. 2 Sulfhydryls can interact to help stabilize the structure of proteins. Covalent bond. "cross linking" TERM 27

Phosphate Group

DEFINITION 27 Consists of a phosphorus atom bound to 4 oxygen atoms (3 w/ single bonds and one with a double bond). Connects to the carbon backbone via one if its O atoms. Anions with 2 negative charges because 2 protons dissociate from the O atoms. One function- transfer energy between organic molecules. Potential to react with water and release energy. Contributes - charge (1- in middle, 2- at the end) TERM 28

Methyl

DEFINITION 28 (-CH3) Most hydrophobic. More O, more covalent TERM 29

Atomic Mass Unit

DEFINITION 29 mass of one proton or neutron. AMU or 1 dalton or 1.7e- TERM 30

Mass of 1 electron

DEFINITION 30 9e-

Mass Number

Protons + Neutrons TERM 32

Isotopes

DEFINITION 32 Forms of an element with different numbers of neutrons, this different mass numbers. TERM 33

Radioisotopes

DEFINITION 33 unstable and give off energy in the form of alpha, beta, and gamma radiation from the nucleus. This RADIOACTIVE DECAY transforms the atom, including changes in the number of protons. Can be incorporated into molecules and act as a "tag" or label. TERM 34

Common structural components of

prokaryotic and eukaryotic cells

DEFINITION 34

1. Plasma Membrane- selective barrier; double layer of phospholipids. Phospholipid bilayer. All biological membranes contain proteins. 2. Cytosol- semifluid substance contained within the PM. 3. Chromosomes (DNA) 4. Ribosomes- make proteins TERM 35

Prokaryotic Cells

DEFINITION 35 identified by a negative trait-absence of a membrane-bound nucleus

Eukaryotic Cells

Characterized by a membrane bound nucleus. Also have highly developed internal membrane systems, membrane bound organelles. TERM 37

Advantages to Compartmentalization

DEFINITION 37

1. Increases the efficient of chemical reactions. 2. Substrates can be localized and maintained at high concentrations within organelles. 3. groups of enzymes that need to work together can be clustered together, both within a compartment or on internal membranes. ***Membranes can work as a compartment TERM 38

Nuclear Envelope

DEFINITION 38 double-membrane surrounding the nucleus TERM 39

Nuclear Pores

DEFINITION 39 control movement of proteins and RNAs into and out of the nucelus TERM 40

Nuclear Lamina

DEFINITION 40 inside then nuclear envelope- made of intermediate fibers. Gives the nucleus shape and structure

Nuclear Matrix

inside the nucleus. Chromatin is suspended. TERM 42

Nucleolus

DEFINITION 42 Most prominent structure within the nucleus-site of ribosome unit assembly. Ribosomal RNA is synthesized and the large and small subunits of the ribosome assemble. TERM 43

Nucleus

DEFINITION 43 All euk. have a large nucleus surrounded by the nuclear envelope. The envelope is studded with nuclear pores. Just inside the nuc. env. is the nuclear lamina. Inside the nucleus there nuclear matrix. Most prominent structure is the NUCLEOLUS. *****The nucleus is the principal site for DNA replication and RNA synthesis. Connected by nuclear pores to the cytosol (cytoplasm=cytosol + organelles). contains the main genome (info center of the cell) TERM 44

Eukaryotes

DEFINITION 44

1. Nucleus. 2. Mitochondria. 3. Chloroplasts and Plastids 4. Peroxisomes. 5. Endomembrane system- nuclear envelope, ER, Golgi Apparatus, lysosomes, vacuoles, plasma membrane TERM 45

Mitochondria

DEFINITION 45 Powerhouse of the cell. Generates most of the ATP required to sustain cellular activity. Enclosed by a double membrane. Outer mt membrane. Inner membrane, involuted, form multiple CRISTAE. ***Inner membrane being used as a platform, organize protein complexes. Inside the mt, have the MATRIX. Main function is ATP production. **has its own genome. DNA

Nucleolus + Protein Synthesis

(a dense structure visible in the nondividing nucleus) synthesizes ribosomal RNA and combines it with protein to assemble ribosomal subunits, which then pass through nuclear pores to the cytoplasm. TERM 47

Integral Membrane Proteins

DEFINITION 47 penetrate the membrane (have a domain which is hydrophobic that resides within the hydrophobic core of the lipid bilayer). Transmembrane proteins that span the membrane have a specific directional orientation in the membrane. TERM 48

Peripheral Membrane Proteins

DEFINITION 48 associated with the membrane, but do not penetrate the hydrophobic core of the bilayer.