Topic 4

Question 1

what are enzymes?

Answer 1

proteins

Question 2

what are proteins?

Answer 2

polypeptide that is folded into a specific 3D shape

Question 3

what is a peptide bond?

Answer 3

a polar covalent bond between amino acids

Question 4

characteristics of hydrophobic R groups?

Answer 4

many non polar bonds
-inside away from water

Question 5

characteristics of a hydrophilic R group?

Answer 5

side chains with oxygen, nitrogen or charged atoms
-on the outside of an amino acid

Question 6

what happens when an acid loses a proton at ph7?

Answer 6

it becomes negatively charged

Question 7

what happens when an acid gains a proton at ph7?

Answer 7

it becomes positively charged

Question 8

what is a peptide?

Answer 8

polymer of amino acid

Question 9

what is a polypeptide?

Answer 9

polymer of more than 10 amino acids

Question 10

what is the primary structure of a polypeptide?

Answer 10

literal sequence of amino acids (straight line)

Question 11

what is the secondary a structure of a polypeptide?

Answer 11

the primary structure folded into helices
-stabilized by hydrogen bonding by carboxyl groups and amide groups

Question 12

what is the secondary b structure of a polypeptide?

Answer 12

primary sequence is folded into sheets
-stabilized by hydrogen bonds between carboxyl groups and amide groups

Question 13

what is tertiary structure of a polypeptide?

Answer 13

the secondary structure is folded into the 3D shape of a protein
-due to multiple levels of interaction between the R-groups (HB, ionic interactions, Vanderwaals, covalent bonds)

Question 14

what is quaternary structure of a polypeptide?

Answer 14

4 subunits each with tertiary structure

Question 15

secondary structure of hexokinase?

Answer 15

helices, sheets, and turns made by the primary structure

Question 16

tertiary structure of hexokinase?

Answer 16

overall shape of a protein which results from the organisation of secondary structural regions relative to another

Question 17

what is activation energy?

Answer 17

the energy required to get a reaction going

Question 18

how does activation energy work?

Answer 18

energy destabilizes the bonds in the reactants which allows the for the formation of the generation of products

Question 19

what is a transition state?

Answer 19

the point where bonds in reactants are breaking and bonds of products are forming
-summit of Ea hill

Question 20

what are ways to speed up a chemical reaction?

Answer 20

increase temperature
increase concentration of reactants
add a catalyst

Question 21

what are examples of a catalyst?

Answer 21

enzyme- protein catalyst
robozyme- RNA catalyst

Question 22

what do catalysts do?

Answer 22

decrease activation energy speeding up reaction time

Question 23

what is an active site of an ezyme?

Answer 23

a region that interacts with one or more specific substrates

Question 24

what happens when a substrate binds to an enzymes active site?

Answer 24

the enzyme changes shape forming an enzyme-substrate complex

Question 25

what does the ES complex do?

Answer 25

forces the products into the transition state

Question 26

how does an enzyme get back to how it was originally?

Answer 26

it released the products changing the enzymes back into its original shape

Question 27

how do cells regulate enzyme kinetics?

Answer 27

by changing the concentration of inhibitors or the concentration of activators

Question 28

what does the rate of an enzyme reaction depend on?

Answer 28

the concentration of enzyme and the concentration of substrate

Question 29

what influences how fast a cell can convert substrate into products?

Answer 29

the rate of an enzyme reaction

Question 30

what is denaturation?

Answer 30

loss of protien structure

Question 31

characteristics of denaturation?

Answer 31

partial or complete reversible or irreversible caused by heat, pH and non-competitive inhibitors

Question 32

what is inactivation?

Answer 32

loss of protein activity

Question 33

characteristics of inactivation?

Answer 33

reversible or irreversible due to denaturation

Question 34

what is a reversible competitive inhibitor?

Answer 34

an inhibitor that is chemically like the substrate -inhibitor noncovalently binds to an enzymes active site and competes with the substrate for binding to the active site -molecule with the highest concentration outcompetes the other

Question 35

what does competetive inhibition affect?

Answer 35

Km increases, vm is the same

Question 36

what is reversible non-competitive inhibition?

Answer 36

inhibitor is unlike the substrate -inhibitor noncovalently binds to allosteric site -high concentrations of substrate can't outcompete inhibitor

Question 37

what does a non-competitive inhibitor affect?

Answer 37

decreases Vmax, Km stays the same

Question 38

what are allosteric enzymes?

Answer 38

biochemical pathways that include regulatory enzymes that control the rate of the entire pathway

Question 39

what are allosteric activators?

Answer 39

bind to the enzyme which will change shape to a more active form

Question 40

what are allosteric inhibitors?

Answer 40

bind to the enzyme which will change shape to a less active form

Question 41

what is feedback inhibition?

Answer 41

the final product of a pathway inhibits an enzymes early in the pathway