Exam I Vocabulary B

Question 1

Primary Protein Structure

Answer 1

amino acid sequence

Question 2

Secondary Protein Structure

Answer 2

local structure; alpha helices and beta sheets

Question 3

Tertiary Protein Structure

Answer 3

folded structure of the entire polypeptide chain

Question 4

Quaternary Protein Structure

Answer 4

arrangement of multiple subunits into a larger complex

Question 5

Homodimer

Answer 5

two copies of the same protein which bind together

Question 6

Heterodimer

Answer 6

two different proteins which bind together

Question 7

Alpha Helix

Answer 7

hydrogen bonds

Question 8

Alpha Helix

Answer 8

hydrogen bonds and pi stacking aromatic molecules; certain; often transmembrane part of a protein

Question 9

Beta Sheet

Answer 9

can let a protein interact with two different kinds of regions because it’s double sided; two or more chains of amino acids; can be antiparallel or parallel

Question 10

Antibody

Answer 10

binds antigens very specifically; in some cases, antibody can distinguish between proteins that differ by a single amino acid

Question 11

Antigen

Answer 11

foreign substance that elicits production of an antibody

Question 12

Heavy Chain

Answer 12

larger part of the antibody

Question 13

Light Chain

Answer 13

smaller part of the antibody

Question 14

Enzyme

Answer 14

speed up reactions by factors of 10^6 or more;

Question 15

Catalyst

Answer 15

lower the activation energy by interacting with transition state (free energy of substrates and products remain the same)

Question 16

Enzyme

Answer 16

speed up reactions by factors of 10^6 or more; usually has “-ase” at the end; lowers activation energy of a reaction

Question 17

Enzyme

Answer 17

speed up reactions by factors of 10^6 or more; usually has “-ase” at the end; lowers activation energy of a reaction; facilitate orientation of substrates, change reactivity of substrates, induce strain on substrates

Question 18

Substrate

Answer 18

a molecule that undergoes an enzyme-catalyzed reaction; becomes a product after reacting with an enzyme

Question 19

Product

Answer 19

differs from substrates by one or more covalent bonds

Question 20

Activation Energy

Answer 20

the difference between the energy of the reactants and the energy of the transition state; must be overcome for the reaction to occur; lowered by the catalyst

Question 21

Allosteric Regulation

Answer 21

conformation of enzyme changes shape upon binding a regulatory molecule (ligand); binds somewhere other than the active site and induce a conformational change that affects the substrate binding to the active site

Question 22

Competitive Inhibition

Answer 22

block substrates from binding to the active site

Question 23

Ion Exchange Chromatography

Answer 23

separates proteins by charge; charged beads attract a proteins of a certain charge, while the other ones move through the column more quickly

Question 24

Gel Filtration Chromatography

Answer 24

separates proteins by size; small molecules enter aqueous spaces within beads

Question 25

Affinity Chromatography

Answer 25

separates proteins based on specific interactions

Question 26

Peptide

Answer 26

usually contain less than 20-30 amino acids

Question 27

Polypeptide

Answer 27

linear polymers of amino acids

Question 28

Peptide Bond

Answer 28

chemical bond formed between amino acids, constituting the primary linkage in all protein structures

Question 29

Monomer

Answer 29

a molecule that can be bonded to other identical molecules to form a polymer

Question 30

Dimer

Answer 30

a molecule consisting of two identical molecules linked together

Question 31

Free Energy

Answer 31

thermodynamic quantity equivalent to the capacity of a system to do work

Question 32

Transition State

Answer 32

the particular configuration along the reaction coordinate; it is defined as the state corresponding to the highest potential energy along the reaction coordinate

Question 33

Delta G

Answer 33

change in free energy involved in a chemical reaction

Question 34

Exergonic

Answer 34

a metabolic or chemical process accompanied by the release of energy

Question 35

Endergonic

Answer 35

a metabolic or chemical process accompanied by or requiring the absorption of energy, the products being of greater free energy than the reactants

Question 36

Coupled Reaction

Answer 36

chemical reaction with a common intermediate in which energy transferred from one side of the reaction to the other; ex. ATP

Question 37

Active Site

Answer 37

the location on the protein where the ligand binds