ENZYMOLOGY P1

Question 1

ENZYME CONCENTRATION

Answer 1

higher the enzyme concentration, the
faster is the reaction, because more
enzyme is present to the substrate

Question 2

SUBSTRATE CONCENTRATION

Answer 2

With the amount of enzyme exceeding the
amount of substrate, the reaction rate
steadily increases as more substrate is
added
• However, when the substrate
concentration reaches a maximal value,
higher concentration of substrate no
longer results in increased rate of reaction

Question 3

Enzymes are active at

Answer 3

25°C, 30°C, 37°C

Question 4

optimum temperature for
enzymatic activity

Answer 4

37°C

Question 5

↑temp: __ reaction

Answer 5

↑reaction

Question 6

Rate of denaturation _____ as
temperature increases

Answer 6

increases

Question 7

Temperature that may result to inactivation of enzymes

Answer 7

60-65°C

Question 8

Temperature Coefficient (Q10):

Answer 8

every 10°C increase in temp, there will be a 2x increase in enzyme activity

Question 9

Most reactions occur in pH of

Answer 9

7-8

Question 10

Extreme pH level may cause

Answer 10

Denaturation

Question 11

Low temperatures (refrigeration/freezing)
cause enzyme to be

Answer 11

reversibly inactive

Question 12

Repeated freezing and thawing

Answer 12

denaturation

Question 13

ideal temp. for preservation of
enzymes

Answer 13

-20°C

Question 14

ideal storage temp for substrates
and coenzymes

Answer 14

2-8°C

Question 15

ideal for storage of LDH (LD4 and
LD5)

Answer 15

22°C

Question 16

mostly increases enzyme concentration

Answer 16

Hemolysis

Question 17

mostly decreases enzyme concentration

Answer 17

Lactescence or Milky spx.

Question 18

Shape of substrate (key) must fit into
enzyme (lock)

Answer 18

EMIL FISHER’S LOCK AND KEY THEORY

Question 19

Based on the substrate binding to the
active site of the enzyme

Answer 19

KOCHLAND’S INDUCED FIT THEORY

Question 20

An enzyme combines with one substrate and catalyzes one reaction

Answer 20

ABSOLUTE SPECIFICITY

Question 21

An enzyme combines with substrates
in a chemical group

Answer 21

GROUP SPECIFICITY

Question 22

An enzyme reacting with chemical
bonds

Answer 22

BOND SPECIFICITY

Question 23

The reaction rate depends only on
enzyme concentration

Answer 23

ZERO-ORDER REACTION

Question 24

The reaction rate is directly
proportional to substrate
concentration

Answer 24

FIRST-ORDER REACTION

Question 25

• The reactants are combined • The reaction proceeds for a designated time • The reaction is stopped, and measurement is made

Answer 25

FIXED-TIME

Question 26

• Multiple measurements of change in absorbance made during the reaction • it is preferred than fixed-time

Answer 26

CONTINUOUS MONITORING/KINETIC ASSAY

Question 27

ENZYMES ARE MEASURED IN TERMS OF

Answer 27

1. Change in the substrate concentration 2. Change in the product concentration 3. Change in coenzyme concentration

Question 28

CAUSES OF ELEVATED PLASMA ENZYME LEVELS

Answer 28

1. Impaired removal of enzyme from plasma 2. Impaired permeability of cell membrane 3. Increased in the number of cells or the production of cells 4. Increased in normal cell turnover 5. Decreased clearance of enzymes from the circulation 6. Tissue necrosis and degeneration

Question 29

specific biologic proteins that catalyze biochemical reactions without altering the equilibrium point of the reaction or being consumed or changed in composition

Answer 29

ENZYMES

Question 30

A cavity other than the active site

Answer 30

Allosteric site

Question 31

Forms of an enzyme could be based on physical properties such as

Answer 31

• Electrophoretic mobility • Solubility, or • Resistance to inactivation

Question 32

Fraction of an enzyme

Answer 32

ISOENZYME

Question 33

Necessary for enzyme activity

Answer 33

COFACTOR

Question 34

Inorganic cofactors

Answer 34

ACTIVATOR

Question 35

Organic cofactors

Answer 35

COENZYME

Question 36

Coenzyme bound tightly to the enzyme

Answer 36

PROSTHETIC GROUP

Question 37

Enzyme secreted from the organ of production in a structurally inactive form

Answer 37

ZYMOGEN

Question 38

Prevents an enzymatic reaction to occur

Answer 38

INHIBITOR

Question 39

Physically binds to the active site of an enzyme; reversible

Answer 39

COMPETITIVE INHIBITOR

Question 40

Looks for areas other than the active site; slows the rate of the reaction

Answer 40

NON-COMPETITIVE INHIBITOR

Question 41

The inhibitor binds the enzyme-substrate complex

Answer 41

UNCOMPETITIVE INHIBITOR

Question 42

Assigned systematic name to each enzyme

Answer 42

INTERNATIONAL UNION OF BIOCHEMISTRY

Question 43

FIRST DIGIT

Answer 43

Enzyme Class

Question 44

SECOND AND THIRD DIGIT

Answer 44

Enzyme Sub-Class, Sub-sub-class

Question 45

FOURTH DIGIT

Answer 45

Serial number specific to an enzyme

Question 46

Catalyze an enzyme-reduction reaction between two substrates

Answer 46

OXIDOREDUCTASE

Question 47

Catalyze the transfer of a group other than the hydrogen from one substrate to another

Answer 47

TRANSFERASE

Question 48

Catalyze hydrolysis of various bonds

Answer 48

HYDROLASE

Question 49

Catalyze removal of groups from substrates without hydrolysis

Answer 49

LYASE

Question 50

Catalyze the interconversion of geometric, optical, or positional isomers

Answer 50

ISOMERASE

Question 51

Catalyze the joining of two substrate molecules, coupled with a breaking of the pyrophosphate bond in ATP or similar

Answer 51

LIGASE