Biology Exam 2

Question 1

Ligase

Answer 1

Formation of c-c, c-o, c-s, or c-n bonds using ATP cleavage

Synthetases

Question 2

Transferase

Answer 2

Transfer of functional groups

Kinases, Transaminases

Question 3

Lyase

Answer 3

Cleavage of c-c, c-o, c-n and other bonds by means other than hydrolysis or oxidation

Decarboxylases

Question 4

Hydrolase

Answer 4

Formation of two products by hydrolyzing a substrate

peptides

Question 5

Isomerase

Answer 5

Intramolecular rearrangements, transfer of groups within molecules

Mutases

Question 6

Acid/Base

Answer 6

name from the perspective of enzyme
General: AA fun group
Specific: H2O (acceptor or donor)
Addition or loss of proton to make enzyme a better nucleophile or electrophile.

Question 7

Electrostatic

Answer 7

The presence of opposite charges to stabilize the transition state of the substrate
Salt Bridge

Question 8

Proximity and Orientation

Answer 8

Substrate first bind in the enzyme active site in the correct position

Always happens first

Question 9

Oxidoreductase

Answer 9

Oxidation – Reduction
Transfer of H or O atoms
Oxidases (NAD+, NADH)

Question 10

Metal Ion

Answer 10

The presence of inorganic material to stabilizes the transition state of the substrate.

Question 11

Covalent

Answer 11

Formation of transilent covalent Bond
Formation of bond to stabalize the transition state of the substrate in the enzyme pocket.

Question 12

What are the non-covalent interactions that could be made?

Answer 12

Vandaar waals
Hydrogen
Ionic

Question 13

Ka

Answer 13

Association constant going to PL

Question 14

Kd

Answer 14

Dissasociation constant going to P+L

Question 15

Fractional Saturation

Answer 15

Occupied binding sites/Total binding sites

Question 16

Protein-ligand interactions

Answer 16

-Reversible binding of P/L non-covalent interactions.
-Ligand binding induces conformational change.
-Equilibrium can be altered by effector molecules, can bind to protein and induce structure change.

Question 17

Unbound

Answer 17

T-State, Tense

Question 18

Bound

Answer 18

R-State, Relaxed

Question 19

Negative effector

Answer 19

Stabilize the T state.

Question 20

Smaller Kd

Answer 20

higher affinity

Question 21

Larger Kd

Answer 21

lower affinity

Question 22

Stabilizing Transition State

Answer 22

There are more and stronger enzymes and non-covalent interactions

Question 23

Increase reaction rate

Answer 23

-Stabilize transition site
-Provide an alternate path
-Product formation
-orient the substrates appropriately

Question 24

Cofactor

Answer 24

Provides additional chemical groups to supplement the chemistry of AA functional groups

Question 25

Metals

Answer 25

Provide different function than AA

Question 26

Coenzyme

Answer 26

Cofactor with an organic component.

Question 27

Prosthetic group

Answer 27

Coenzyme permanently associated with an enzyme Ex. Iron in hemoglobin

Question 28

Kinetics

Answer 28

quantitative study of the RATES of chemical rxn's performed by enzymes

Question 29

1st order S-->P

Answer 29

isomerization

Question 30

Assumptions

Answer 30

[S]>>>>[E] The substrate is higher than the enzyme Rxn is considered early [S] is constant [P] near 0. Steady State [ES] constant Product release is very fast.

Question 31

Vmax

Answer 31

velocity can not increase any more even with more substrate.

Question 32

Kcat

Answer 32

to turn over number = vmax/ E+

Question 33

Competitive Inhibitors

Answer 33

- Bind to free enzyme -Bind to active site of free enzyme

Question 34

Uncompetitive inhibitors

Answer 34

ES allosteric

Question 35

Mixed inhibitors

Answer 35

- Bind to enzyme and enzyme substrate. - Allosteric

Question 36

Inreverable inhibition

Answer 36

induces the formation of covalent bonds

Question 37

Analog

Answer 37

Molecule that is similar

Question 38

Permenant irreversable

Answer 38

Chemically similar to transition state

Question 39

Allosteric regulation

Answer 39

1 molecule turn on 1 turns off

Question 40

Km

Answer 40

substrate at 1/2 concentration

Question 41

Km-apparent

Answer 41

describes km when inhibitors are present

Question 42

Vo

Answer 42

inital velocity( rate of conversion of substrate to product)

Question 43

vmax

Answer 43

maximum velocity (substrate can no longer increase [S]-->[P]