Chapter 6 - Enzyme Flashcards Preview

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Flashcards in Chapter 6 - Enzyme Deck (50)
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1

Nature of chemical rxn in biology world?

thermodynamic favorable but kinetics controlls (very slow without catalyst)

2

How to change the rate of reaction?

increase temperature, concentration of reactants, add catalyst

3

What are enzyme characteristics?

enhance rxn rate

mild condition

reaction speicificty 

regulation activity

4

What are the forces that are used in enzyme/substrate interactions?

Vander Waals interactions

H-bond

hydrophobic interactions

electrostatic interactions

5

Factor contributes to substrate binding

geometric complimentarity

electronic complimentarity (lock and key)

induced fit

6

induced fit

the binding of substrate can induce conformational change in enzyme to accomodate both geometric and electronic complementarity

7

Type of enzyme

Oxidoreductase

Transferase

Hydrolase

Lyases

Isomerases

Ligases

8

Oxidoreductase

transferase

hydrolase

redox reaction

transfer of funcional groups

hydrolysis reactions

9

Lyase

Isomerase

Ligase

Group elimination to form double bonds

isomerization rxn

bond formation coupled with ATP hydrolysis

10

How does enzyme distinguish the substrates?

through enzyme's functional groups in active site

11

Mild condition of enzyme

enzyme-rxn can occur at normal temp and pressure 

12

Regulation activity of enzyme

allosteric regulation

post-translational modification of enzyme

up and down regulation for concentration of enzyme

13

What doe enzyme do to the delta G++?

It lower the activation energy by lowering the transition state energy

14

What are 3 chemical catalytic mechanism of enzymes?

acid-base catalysis

transient covalent catalysis

metal ions catalysis (charge-charge interaction)

15

What do 3 chemical catalytic mechanisms need? 

amino acid side chains

16

cofactor

Type of cofactos

required for functional group transfer or redox reaction

metal ions and coenzymes (cosubstrate and prosthetic group)

17

cosubstrate

prosthetic group

transient association with enzyme - leave/enter with substrate

permanent association with active site of enzyme

18

Common metal ions in cofactors

Ca2+, Mg2+, Fe3+, Cu2+, Zn2+

19

Apoenzyme

Holoenzyme

enzymes after removing cofactors

enzyme-cofactor complex

20

vitamin

Where does vitamin exist? Can it be synthesized by our body?

the compounds are used as precursors for coenzyme biosynthesis

No, it exists only in diet

21

Type of vitamin

which one is used for biosynthesis?

water soluble and water insoluble

water soluble

22

transition state

Delta G++

the state where bonds are broken and formed (A- - B - -C)

activation energy - energy required for reactants to reach the transition state

23

The higher delta G++

The lower delta G++

the longer the rxn will take

the shorter the rxn will take

24

How much delta-G++ have to decrease to increase rxn by 10-fold?

1.36 kcal/mol (5.71 kJ/mol)

25

Formula for calculate the increase rxn rate by decreasing delta G++?

V = e^(delta-G++ /RT)

26

What does enzyme have when at the transition state? What is downside of this?

higher affinity to the substrate

for compounds mimics the transition state, it can have very high affinity to bind with enzyme and can be great inhibitors

27

acid catalysis

the process in which the transfer of proton from acid lower the free energy of reactant's transition state

28

base catalysis

the process in which the abstraction of proton by a base lower the free energy of reactant's transition state

29

Covalent catalysis

what is the other name for covalent catalysis

the process in which the covalent bonds form between enzyme and substrate

nucleophilic catalysis

30

nucleophilic catalysis

the process in which nucleophiles of enzyme attack the electrophile on substrates