Enzymes

Question 1

Diverse group of water-insoluble biological molecules; fats – energy stores; phospholipids and sterols – major
components of membrane.

Answer 1

Lipids

Question 2

Polyhydroxy aldehydes and ketones with the
general formula of (CH2O)n.

Answer 2

Carbohydrates

Question 3

Most complex and most abundant
organic molecules containing at least one
carboxyl group and one amino group.

Answer 3

Proteins

Question 4

DNA carries coded information, arranged into genes, that is passed from each cell to its daughter cells and from one generation to the next; RNA instrumental in translating the coded message of DNA into sequences of amino acids during synthesis of protein molecules

Answer 4

Nucleic Acid

Question 5

The process of increasing the rate of reaction with the use of a catalyst.

Answer 5

Catalysis

Question 6

Any substance that increases rate of reaction upon addition to a certain reaction

Answer 6

Catalyst

Question 7

Catalyst of biochemical reactions (biological catalysts). Neither used up in the reaction nor do they appear as reaction products

Answer 7

Enzymes

Question 8

Catalyzes all the synthetic and metabolic
reactions of the cell that allows for a faster speed of reaction. Increases the rate of reaction by means of
lowering the activation energy

Answer 8

Enzymes

Question 9

Measured as the number of calories required to bring all the molecules in a mole of reactant at a given temperature to a reactive (or activated) state.

Answer 9

Activation energy

Question 10

How do enzymes hasten the reaction?

Answer 10

Enzyme lowers the activation energy needed

Question 11

Enzyme (E) binds with a substrate (S) to form an activated:

Answer 11

Enzyme-substrate complex (ES)

Question 12

reactions catalyzed by enzymes are usually __________ to ________ times faster than uncatalyzed reactions.

Answer 12

10^3 to 10^17

Question 13

Trait of an enzyme being specific for a certain substrate:

Answer 13

Enzyme Specificity

Question 14

Specificity of enzymes varies on:

Answer 14

Stereoisomerism

Question 15

Enzyme present in the intestine that hydrolyses any peptide bond where the carbonyl belongs to a phenylalanine, tyrosine, or tryptophan residue.

Answer 15

Chymotrypsin

Question 16

Close and complementary fit between enzymes and substrate in a special portion of the enzyme surface

Answer 16

Active Site

Question 17

Two enzyme-substrate complex models

Answer 17

Lock and Key model, Induced Fit model

Question 18

Catalytic potential of an enzyme

Answer 18

Enzyme activity

Question 19

Number of reactions catalyzed per second by the enzyme

Answer 19

Turnover number

Question 20

How enzymes accelerate reactions

Answer 20

1. Hold substrates in close proximity; increasing reaction probability
2. Presence of proton donors and acceptors in the binding site
3. Forms an unstable intermediate that readily
   undergoes second reaction

Question 21

Factors affecting Enzyme activity

Answer 21

temperature, pH level, cofactors, and coenzymes

Question 22

Increases enzymatic activity by increasing the kinetic energy, thus number of molecular collisions increases, increasing the probability of reaction between molecules

Answer 22

Temperature

Question 23

An extreme increase in temperature leads to the __________ of the enzymes

Answer 23

denaturation

Question 24

in pH level exposes more positive sites in the enzyme for interactions with negative groups on substrates

Answer 24

Drop

Question 25

_____ in pH level facilitates the binding of positive groups in a substrate to negative sites in the enzyme

Answer 25

Rise

Question 26

Small organic molecules that act as cofactors

Answer 26

coenzymes

Question 27

An enzyme minus its cofactor; cannot function without its cofactor/coenzyme.

Answer 27

Apoenzyme

Question 28

Cofactor + apoenzyme

Answer 28

Holoenzyme

Question 29

Enzyme that facilitates oxidation-reduction reaction

Answer 29

Oxidoreductase

Question 30

Enzyme that catalyzes the transfer of functional groups

Answer 30

Transferases

Question 31

Enzymes that facilitate Hydrolysis reactions

Answer 31

Hydrolase

Question 32

Enzyme that facilitates the addition or removal of groups to form double bonds

Answer 32

Lyase

Question 33

Enzyme that facilitates Isomerization(intramolecular group transfer)

Answer 33

Isomerase

Question 34

Enzymes that facilitate ligation of two substrates at the expense of ATP hydrolysis

Answer 34

Ligases

Question 35

The rate at which an enzymatic reaction proceeds depends on the concentrations of substrate, product, and active enzymes.

Answer 35

Enzyme Kinetics

Question 36

Means of controlling enzymatic reactions used by living cells.

Answer 36

Enzyme Inhibition

Question 37

Two types of Enzyme Inhibition

Answer 37

Competitive and Non-competitive

Question 38

Inhibition where inhibitor molecules directly reacts with the active site of an enzyme

Answer 38

Competitive inhibition

Question 39

Most common type of competitive inhibition

Answer 39

Substrate analogs

Question 40

Caused by inhibitor molecules that bind outside the active site.

Answer 40

Non-competitive inhibition

Question 41

Regulation of metabolic reactions

Answer 41

1. Control of Enzyme Synthesis 2. Control of Enzyme Activity 3. End-product(feedback) inhibition

Question 42

Alters the tertiary structure of an enzyme thus changing the conformation of the active site

Answer 42

allosteric site

Question 43

Interactions of the end products in the allosteric site, making the end product an _________________

Answer 43

allosteric inhibitor

Question 44

Some cat-ion cofactors acts as allosteric activators for some enzyme

Answer 44

Enzyme Activation

Question 45

Two kinds of metabolic pathways in animal tissues

Answer 45

Anaerobic and aerobic

Question 46

Metabolic pathway where food molecules are completely oxidized to carbon dioxide and water by molecular oxygen. Greater energy yield

Answer 46

Aerobic metabolism

Question 47

Incomplete oxidation of food molecules converting it to lactic acid; due to absence of oxygen

Answer 47

Anaerobic metabolism