EXAM 3 Lec 10

Question 1

enzymes

Answer 1

flexible and undergo staged shape changes during a catalytic reaction

Question 2

what do the sequences of amino acids in proteins determine

Answer 2

the shape and potential noncovalent reactions

Question 3

regulator molecules

Answer 3

change enzyme shape, affecting the activity of enzymes

Question 4

primary structure

Answer 4

sequence of amino acids linked by peptide bonds
determines how the poly peptide interacts with itself and how it interactions with other proteins, ligands, and macromolecules.

Question 5

secondary structure

Answer 5

nearby noncovalent interactions

hydrogen bonds in the polypeptide backbone create common folding patterns of alpha helices and beta sheets

Question 6

tertiary structure

Answer 6

3-dimensional structure of one polypeptide
globular proteins are spherical (enzymes)
fibrous proteins are elongated (structural proteins)
includes secondary structures

Question 7

quaternary structure

Answer 7

proteins where two or more polypeptides form a functional complex held together by noncovalent bonds
can form the same (CAP protein) or different (neuraminidase) polypeptides

Question 8

how are proteins shaped and organized

Answer 8

by sequences of amino acids that contribute to shape and potential noncovalent interactions

Question 9

how can protein shape be controlled

Answer 9

by molecules interacting with the protein
chemical modification of the amino acids
changes in the surrounding environment that affect noncovalent interactions (pH and temperature)

Question 10

function of enzymes

Answer 10

bind a molecule, convert it to a different one, and then back to the original (bring 2 reactants close and redistribute their electrons)
they change their shape in an orderly process that favors product formation

Question 11

what does the rate of a reaction include

Answer 11

the time the enzyme spends looking/binding to the substrate (dependent on substrate concentration of the enzyme), as well as the time spent converting it to a product

Question 12

Vmax

Answer 12

time spent converting the substrate to a product

point of infinite concentration

Question 13

reaction of the enzyme at low concentrations

Answer 13

the enzyme spends most time looking for the substrate, making the rate low

Question 14

reaction of the enzyme at high concentrations

Answer 14

the enzyme spends less time looking or the substrate, increasing the rate

Question 15

Km

Answer 15

one half Vmax

Question 16

Q10

Answer 16

temperature coefficient

Question 17

effect of temperature on the rate of the reaction

Answer 17

temperature and activity increase together

continues increasing until the enzyme is heat-denatured

Question 18

enzyme shape guides substrates (reactants) towards

Answer 18

product formation

Question 19

how do enzymes affect a reactions energy

Answer 19

they reduce the amount of energy needed to start a reaction

Question 20

allosteric regulation

Answer 20

an enzyme has two sites for interacting with other compounds
the active site and the allosteric regulatory site

Question 21

active site

Answer 21

where the substrate binds and is converted into the product

Question 22

allosteric regulatory site

Answer 22

where another compound binds and affects the activity of the enzyme (usually a compound related to the metabolic pathway of the enzyme)