Enzymes

Question 1

Majority of the chemical reactions in our body are catalyzed by proteins known as?

Answer 1

enzymes

Question 2

____, which are large molecules that increase the rates of chemical reactions without themselves undergoing any change.

Answer 2

enzymes

Question 3

Majority of the enzymes in our body are what type of proteins?

fibrous or globular

Answer 3

globular

Question 4

____ are enzymes made of ribonucleic acids. They catalyze the self-cleavage of certain portions of their own molecules

Answer 4

Ribozymes

Question 5

Like all catalysts, enzymes do not change the chemical what? They, rather, increase the what?

singilan time!!!

Answer 5

chemical equilibrium; reaction rate

enzymes do not change equi just rxn rates

Question 6

Enzymes cause reactions to occur faster by lowering or adjusting the?

Answer 6

activation energy

Question 7

Enzymes increase ____ by anywhere from 10⁹ to 10</sup>20</sup> times

Answer 7

reaction rates

Question 8

A characteristic of an enzyme wherein it is being choosy, to the point of being able to distinguish between the stereoisomers of the same molecule

Answer 8

specific

Question 9

what enzyme catalyzes the hydrolysis of peptide bonds of proteins on the C-side of K & R?

Answer 9

Trypsin

Question 10

what enzymes specifically catalyze the hydrolysis of only the last amino acid on a protein chain – the one on the C-terminal end?

Answer 10

Carboxypeptidases

Question 11

What do you call the enzymes that catalyze the hydrolysis of any triglyceride, but still do not affect carbohydrates or proteins?

Answer 11

Lipases

Question 12

What do you call the protein-splitting enzymes that are in the blood, ready to promote clotting?

Answer 12

Proteases

Question 13

Identify the group of enzyme

catalyze oxidations and reductions

redox reactions or transfer of electrons

Answer 13

Oxidoreductases

EC1

Question 14

Identify the group of enzyme

catalyze the transfer of a group of atoms, such as from one molecule to another

transfer of a group from one substrate to another

Answer 14

Transferases

EC2

Question 15

Identify the group of enzyme

catalyze hydrolysis reactions

addition of water to break bonds

Answer 15

Hydrolases

EC3

Question 16

Identify the group of enzyme

catalyze the addition of two groups to a double bond or the removal of two groups from adjacent atoms to create a double bond

addition of groups to double bonds or removal to form double bonds

Answer 16

Lyases

EC4

Question 17

Identify the group of enzyme

catalyze isomerization reactions

convertion of substrate into its isomer

Answer 17

Isomerases

EC5

Question 18

Identify the group of enzyme

catalyze the joining of two molecules

Joining 2 molecules with the hydrolysis of ATP

Answer 18

Ligases

EC6 or synthetases

Question 19

Identify the group of enzyme

helping the protein move across the cell membrane

this is new btw

Answer 19

Translocase

Question 20

what do you call the measure of how fast an enzyme is able to catalyze the reaction?

Answer 20

Enzyme activity

Question 21

In an enzymatic reaction, what do you call the molecule being acted upon?

Answer 21

Substrate

Question 22

What do you call nonprotein parts of enzymes necessary for catalytic function?

Answer 22

cofactors

Question 23

what do you call organic molecules that act as cofactors?

Answer 23

Coenzymes

Question 24

What do you call the 3-D cavity of the enzyms with specific chemical properties to accommodate the substrate?

Answer 24

Active site

Question 25

What do you call the process that increases the action of an enzyme?

Answer 25

Activation

Question 26

What do you call the process by which a compound binds to an enzyme and lowers its activity?

Answer 26

Inhibition

Question 27

If we keep the concentration of the substrate constant and increase the concentration of enzyme, what will happen to the rxn rate? | increases or decreases

Answer 27

increases | increases linearly

Question 28

# True or False If the enzyme concentrations double, will the rxn rate double as well?

Answer 28

Yes ## Footnote bcoz molar concentration of enzyme is almost always much lower than that of substrate

Question 29

If we increase the substrate concentration and keep enzyme concentration constant, what will happen to the rxn rate? | increases or decreases

Answer 29

increases ## Footnote but reaches a point where rxn rate stays the same even if substrate conc is increased

Question 30

The rxn rate does not increase when substrate conc is further increased at constant enzyme conc. Why? ## Footnote Saturation curve = substrate conc up, enzyme conc constant

Answer 30

(at saturation) substrate molecules are bound to all active sites of an enzyme ## Footnote Increasing the substrate concentration can no longer increase the rate because the excess substrate **cannot find any active sites** to which to bind

Question 31

When temperature is increased in a catalyzed reaction, what will happen to rxn rate?

Answer 31

increases

Question 32

What will happen to the rxn rate when you go beyond the optimal temperature and pH? | increases or decreases

Answer 32

decreases

Question 33

After a small temperature increase above the optimum, the decreased rate could be increased again by doing what?

Answer 33

lowering the temperature

Question 34

Arrhenius suggested that catalysts speed up reactions by combining with the substrate to form some kind of intermediate compound called?

Answer 34

enzyme-substrate complex

Question 35

What do you call the limitation of an enzyme to catalyze specific reactions with specific substrates?

Answer 35

substrate specificity

Question 36

# Identify the enzyme-substrate complex enzyme is a rigid 3-D body wherein active site has a restricted opening into which only one kind of substrate can fit

Answer 36

Lock-and-Key model

Question 37

# Identify the enzyme-substrate complex size and shape of the active site change when substrate enters ## Footnote comparison of changes occurring in the shape of the cavity upon substrate binding to the changes in the shape of a glove when a hand is inserted

Answer 37

Induced-fit model

Question 38

What do you call a molecule that reduces the activity of an enzyme?

Answer 38

inhibitor

Question 39

What do you call the activity-reductor of enzymes wherein they bind to enzymes and then never let go? | renders the enzyme less productive

Answer 39

irreversible inhibitor

Question 40

What do you call the activity-reductors of enzymes that unbind to restore its activity to its initial level?

Answer 40

reversible inhibitors

Question 41

# Identify the type of reversible inhibitor while bound to the active site of the enzyme, substrate cannot bind

Answer 41

competitive inhibitor

Question 42

# Identify the type of reversible inhibitor binds not to the active site of the enzyme. its binding changes the shape of the enzyme, rendering it less efficient

Answer 42

noncompetitive inhibitor

Question 43

# True or False When a competitive inhibitor is present, maximum rxn rate may take place if and only if substrate conc is increased

Answer 43

True ## Footnote inhibitor will be displaced from the active site in accord with Le Chatelier's principle

Question 44

# True or False In the presence of a noncompetitive inhibitor, maximum rxn rate may take place if and only if substrate conc is increased

Answer 44

False ## Footnote noncompetitive inhibitors cannot be displaced by substrates kasi hindi naman sa active sites naka-bind. Therefore, maximum rxn rate will be **lower** than it would be in the absence of an inhibitor

Question 45

What do you call the enzyme regulation process in which formation of a product inhibits an earlier reaction in the sequence?

Answer 45

Feedback control

Question 46

What do you call the inactive forms of enzymes wherein a polypeptide chain must be removed to make them active?

Answer 46

Proenzymes or Zymogens ## Footnote trypsin & chymotrypsin (from -gen precursors); trypsin (from trypsinogen) catalyzes chymotrypsinogen to chymotripsin

Question 47

What do you call the regulation that takes place by means of an event that occurs at a site other than the active site?

Answer 47

Allosterism | any enzyme regulated by this is called allosteric enzyme

Question 48

If a molecule or a substance binds other than the active site, it may enhibit enzyme action wherein the process is called? when enzyme action is stimulated in this process, it is called?

Answer 48

negative modulation; positive modulation

Question 49

the substance that binds to an allosteric enzyme is called a what?

Answer 49

regulator

Question 50

what do you call the site wherein the substance of an allosteric enzyme binds to?

Answer 50

regulatory site

Question 51

What do you call the enzymes that perform the same function but have different combinations of subunits (& diff quaternary structures)?

Answer 51

Isozymes or Isoenzymes

Question 52

What do you call the enzyme derived from yeast?

Answer 52

Invertase

Question 53

This enzyme splits sucrose to gluctose and fructose and classified as a hydrolase

Answer 53

Invertase ## Footnote cleaves glycosidic bonds at a1 b2

Question 54

What is used to monitor enzyme activity in the experiment? | may be colored red or yellow

Answer 54

3, 5-dinitrosalicylic acid (DNS)

Question 55

when dinitrosalicylic acids reacts with sugars to form 3-amino-5-nitrosalicylic acid, what color will be shown?

Answer 55

Red ## Footnote DNS does not react with sucrose

Question 56

Red coloration in dinitrosalicylic acid means that enzyme is active, indicating that the concentration of gluc & fruc is? | high or low

Answer 56

high | higher [gluc] & [fruc] = higher invertase activity

Question 57

What is the official name of Invertase?

Answer 57

B-fructofuranosidase

Question 58

EC classification of Invertase (full)

Answer 58

EC 3.2.1.26