Enzymes

Question 1

Covalent catalysis

Answer 1

Enzyme temporally covalently bonds to the substrates and acts as “electron sink” or “carrier”; it carries the electron for a moment

Question 2

Acid Base Catalysis

Answer 2

Move H+ electron

Question 3

Spacial Enzyme

Answer 3

Increases the likely hood of successful collisions

Question 4

Electrostatic

Answer 4

Use metal or charged ions that helps stabilize some other species

Question 5

Substrate

Answer 5

Molecule upon which an enzyme acts

Question 6

Active site

Answer 6

Location within enzyme where substrate is held during chemical reaction; site of catalysis

Question 7

Lock and key theory

Answer 7

Enzyme active site (lock) already in appropriate confirmation for substrate( key) to bind. Enzyme and substrate complementary
no alterations in 3D or 4D confirmation

Question 8

Induced fit

Answer 8

Enzyme and substrate go conformational changes to interact fully
Substrate changes to fit the shape of the enzyme

Question 9

Apoenzyme

Answer 9

Enzymes without cofactors

Question 10

Haloenzymes

Answer 10

(have)

Enzymes that have cofactors

Question 11

Fat soluble vitamins

Answer 11

DAKE

Question 12

Cofactors

Answer 12

Inorganic molecules or metal ions
- ingested as dietary minerals
Ex: DNA polymerase uses Mg2+ as cofactor

Question 13

Coenzymes

Answer 13

Small organic groups or carriers

vitamins such as NAD+ or FAd, CoenzymeA

Question 14

At saturation

Answer 14

Enzyme working at its maximum velocity called vmax

Question 15

What is the only way to increase vmax

Answer 15

increase enzyme concentration

Question 16

Rate of reaction (V)=

Answer 16

Vmax [S]/ (km + [S])

Question 17

km=

Answer 17

the substrate concentration were Vo = 1/2 Vmax

lower km= better enzyme working

Question 18

Kcat

Answer 18

Turnover number

How many substrates an enzyme can turn into products in 1 sec at max speed

Question 19

Cooperativity

Answer 19

Have a sigmoidal curve
-Have multiple subunits and multiple binding sites
-Binding to one site increases the binding to other to other subunits
Example: Hemoglobin

Question 20

Positive cooperativity

Answer 20

Substrate binding increases affinity for subsequent substrate (hemoglobin)

Question 21

Negative Cooperativity

Answer 21

Negative-cooperatively - Substrate binding decreases affinity for subsequent substrates

Question 22

Optimal Blood pH

Answer 22

7.4

Question 23

Pepsin in stomach pH

Answer 23

2

Question 24

Pancreatic enzyme in small intestine pH

Answer 24

8.5

Question 25

Salinity

Answer 25

Salt concentration increasing= disrupt hydrogen and ionic bonds, causing changes in confirmation of the enzyme and even denaturization

Question 26

Ideal body temp

Answer 26

37C, 98.6F, 310K

Question 27

Competitive Inhibitor

Answer 27

Binding Site: Active Site Impact on Km: Increases Impact on Vmax: not changed -increasing substrate concentration to overcome

Question 28

Non-competitive

Answer 28

Binding Site:Allosteric Site causing confirmation changes in the enzyme Impact on Km: Unchanged Impact on Vmax: Decreases

Question 29

Mixed

Answer 29

Binding Site:Allosteric Site or ES complex Impact on Km: Increases or decreases Impact on Vmax: Decreases

Question 30

Umcompetitive

Answer 30

Binding Site:Allosteric Site only to ES complex and locks the substrate in the enzyme preventing its release Impact on Km: Decrease Impact on Vmax: Decreases

Question 31

Regulated Enzyme

Answer 31

Allosteric Enzyme Covalent (reversible) Enzyme itself "ACE"

Question 32

Allosteric Enzyme

Answer 32

Regulator binds to the non-active site, and it activates/inactivates/inhibits the enzyme -multiple binding sites

Question 33

Covalent (reversible) Modified enzymes

Answer 33

Enzymes can be activated by phosphorylation or dephosphoralation - ex :Glycosylation mainly refers in particular to the enzymatic process that attaches glycans to proteins,

Question 34

Enzyme itself

Answer 34

Zymogens: are secreted in inactive form and are activated by cleavage (because they are dangerous if not controlled) - irreversibly activated - have an "-ogen" ending ex: pepsinogen