Biochem FINAL known topics

Question 1

Cytochrome C

Answer 1

Has Heme cofactor Involved in redox chemistry Soluble e- carrier Takes e- from C3 to C4 one at a time in IMS

Question 2

Types of Enzyme inhibition?

Answer 2

Competitive Inhibitor Uncompetitive Inhibitor Mixed (noncompetitive inhibition) Inactivators

Question 3

Inhibitor definition:

Answer 3

Substances that reduce an enzyme’s activity

Question 4

Competitive inhibitor

Answer 4

• Most common
• Often resembles substrate
• Compete for substrate binding site
• Can be overcome by adding more substrate.
• I binds to E; results in k1 appearance decreasing.

Question 5

Competitive Inhibitor: Km and Vmax

Answer 5

• Km = (K-1 + K2)/k1;
  
  • km = increases
• Vmax = k2[ES] v
  
  • max = unchanged

Question 6

Uncompetitive Inhibition

Answer 6

• I binds to ES only;
• Blocks ES —> E+P K-1 and K2 both are effected,
  
  • K-1 and k2 both decrease;
    
    • which causes km to decrease
    • Vmax also decreases
    • Cannot be overcome by adding more substrate.
• K1 unaffected.

Question 7

Mixed (noncompetitive) Inhibition

Answer 7

• I affects both substrate binding and catalysis.
• I binds to ES + E
• k1, k-1, k2 all decrease
• Km can either increase or decrease
• Vmax decreases
  
  • Plot crosses to the left of the y-axis.

Question 8

Pure noncompetitive inhibition:

Answer 8

• I binds with same affinity to both E + ES
• Km app = Km (no change)
• All lines cross over at some point at the x-axis,
• vmax still causes the y-intercept to be different.

Question 9

Inactivators

Answer 9

Permanently inhibit enzymes Could add new functional group to binding site on an enzyme Affects vmax but not km (mimics non-competitive inhibition)

Question 10

Sulfanilamide

Answer 10

• Competitive Inhibitor
• Inhibits PABA synthesis,
  
  • which disables folate synthesis.
• Doesn’t affect humans since we get folate from our diet.

Question 11

PABA is a precursor for?

Answer 11

Folate

Question 12

What is folate used for?

Answer 12

Needed for DNA synthesis.

Question 13

2 Stages of Glycolysis

Answer 13

• Energy Investment (1-5)
• Energy Recovery (6-10)

Question 14

1st stage of Glycolysis:

Answer 14

• Energy Investment
  
  • Rxns 1-5
  • Consume
    
    • 2 ATPs/Glc
  • Yield
    
    • 2 glyceraldehyde-3-P (GAP)

Question 15

2nd stage of Glycolysis:

Answer 15

• Energy Recovery “payoff”
  
  • Rxns 6-10
  • Yields:
    
    • 2 ATP per GAP
    • 1 Pyruvate per GAP
    • 1 NADH per GAP

Question 16

Competitive Inhibitor Lineweaver-Burk plot

Answer 16

Question 17

Uncompetitive Inhibitor Lineweaver-Burk plot

Answer 17

Question 18

Noncompetitive Inhibitor Lineweaver-Burk plot

Answer 18

Question 19

Ezyme Catalysis

Answer 19

• Enzymes are proteins
  
  • Actvie site
    
    • Specificity (lock and key)
      
      • Complementary: (stereo) (CAnt have mirror image)
        
        • Geometric specificity
        • Electronic

Question 20

Structure of ATP

Answer 20

Question 21

Hexokinase

Answer 21

• First reaction of Glycolysis
  
  • Kinase transfers phosphory group from ATP to Glucose C6
  • Mg2+ shields charges
  • Glucose induces conformational change.

Question 22

Delta G = 0

Answer 22

Equilibrium

Question 23

Delta G > 0

Answer 23

Non-spontaneous; Endergonic

Question 24

Delta G < 0

Answer 24

Spontaneous; Exergonic

Question 25

Defining structures of primary structure?

Answer 25

A.a. sequence and disulfide bonds.

Question 26

Defining structures of secondary structure?

Answer 26

• Spatial arrangement of back bone with minor considerations of side chains.
  
  • a helix
  • B sheets

Question 27

Defining structures of tertiary structure?

Answer 27

Spatial arrangement considering side chains;

• determines where hydrophobic and hydrophilic subunits are.

Question 28

Defining structures of quartenary structure?

Answer 28

Includes subunits of proteins that multiple.

Question 29

Classes of enzymes

Question 30

Glycolysis Net Production

Answer 30

• For every glucose
  
  • 2 ATP
  • 2 NADH
    
    • 2e^- each

Question 31

Where does glycolysis take place?

Answer 31

Cytosol

Question 32

Where does ETC take place?

Answer 32

Mitochondria