mod 3 Goodnotes

Question 1

homotropic effectors

Answer 1

The substrate of the enzyme

Question 2

Heterotropic effectors

Answer 2

Not the enzyme substrate, often a downstream product of the pathway

Question 3

What does V₀ represent in the enzyme kinetics equation?

Answer 3

Initial reaction velocity

Think: ‘Velocity at time zero’

Question 4

What does Vmax signify in enzyme kinetics?

Answer 4

Max rate when all enzymes are saturated

‘Max speed on the enzyme highway’

Question 5

What does [S] represent in the equation?

Answer 5

Substrate concentration

‘S for Substrate’

Question 6

What is Km in the context of enzyme kinetics?

Answer 6

[S] at half Vmax; reflects enzyme’s affinity for substrate

‘Km = kind of match’ (low Km = strong match/affinity)

Question 7

What happens to V₀ as [S] increases?

Answer 7

V₀ increases until enzymes are saturated

Question 8

What is the significance of Vmax?

Answer 8

Once all active sites are full, adding more substrate doesn’t help

Question 9

How does increasing the amount of enzyme affect Vmax?

Answer 9

Higher Vmax due to more ‘workers’ processing substrate

Question 10

What does a low Km value indicate?

Answer 10

High affinity (enzyme grabs substrate easily)

Question 11

What does a high Km value imply?

Answer 11

Low affinity (needs more substrate to get to ½ Vmax)

Question 12

What is the relationship between [S] and Km in cells?

Answer 12

[S] ≈ Km; small [S] changes can cause big V₀ changes

Question 13

What assumption is made about substrate concentration in enzyme-substrate interactions?

Answer 13

[S] ≫ [E] — substrate is much more than enzyme

Question 14

What does the Lineweaver-Burk plot represent?

Answer 14

Reciprocal of the Michaelis-Menten equation

Question 15

What does the Y-intercept of a Lineweaver-Burk plot represent?

Answer 15

1/Vmax

Question 16

What does the X-intercept of a Lineweaver-Burk plot represent?

Answer 16

-1/Km

Question 17

What are the two types of plots used in enzyme kinetics?

Answer 17

Michaelis-Menten and Lineweaver-Burk

Question 18

How do Michaelis-Menten and Lineweaver-Burk plots differ in shape?

Answer 18

Michaelis-Menten is hyperbolic, Lineweaver-Burk is linear

Question 19

What unique behavior do allosteric enzymes exhibit?

Answer 19

Sigmoidal (S-shaped) curves due to cooperativity

Question 20

What is the Hill Equation used for?

Answer 20

Describing allosteric enzyme kinetics

Question 21

What does K₁/₂ represent in the context of allosteric enzymes?

Answer 21

[S] at ½ Vmax

‘Halfway mark’ for allosteric enzymes

Question 22

What does the variable ‘n’ in the Hill Equation indicate?

Answer 22

Degree of cooperativity

‘n for team Number’ — how much subunits cooperate

Question 23

What is the effect of positive effectors on enzymes?

Answer 23

↑ Affinity (↓ K₁/₂), ↑ Vmax

Question 24

What is the effect of negative effectors on enzymes?

Answer 24

↓ Affinity (↑ K₁/₂), ↓ Vmax

Question 25

Complex I

Answer 25

NADH-conenzyme Q oxidoreductase

Question 26

Complex II

Answer 26

Succinate-conenzyme Q oxidoreductase

Question 27

Complex III

Answer 27

Conenzyme Q-cytochrome C oxidoreductase

Question 28

Complex IV

Answer 28

Cytochrome C Oxidase

Question 29

Complex I Results

Answer 29

2e- from NADH pump 4H+

Question 30

Complex III Results

Answer 30

e- from NADH & FADH2 pump H+

Question 31

Complex IV Results

Answer 31

1) 4e- from complex III pump 4H+ 2) 4H+ + O2 --> 2H2O @ matrix

Question 32

2 Types of Shuttles

Answer 32

1) Glycerol 3-phosphate shuttle 2) Malate-aspartate shuttle

Question 34

Glycerol 3-Phosphate Shuttle

Answer 34

NADH --> FADH2 x 2 = 2 ATP NOT the regular 3

Question 35

Malate-Aspartate Shuttle

Answer 35

Transfers e- back to NADH to generate 3 ATP

Question 36

ATP Synthase Equation

Answer 36

ADP + Pi + 3H+ = ATP + H2O + 3H+

Question 37

Fo Portion of ATP synthase

Answer 37

@ inner mitochondrial membrane and contains proton pores

Question 38

F1 portion of ATP synthase

Answer 38

@ matrix and contains catalytic activity

Question 39

Uncoupling Proteins

Answer 39

* Brown fat generates heat in babies and bears (hibernating animals) * Uses Uncoupling Proteins (UCPs) in ETC * Protons bypass ATP synthase, generating heat instead of ATP

Question 40

Oligomycin

Answer 40

* Binds to F₀ domain of ATP synthase * Blocks proton channel → prevent ATP generation and proton gradient → ETC halts

Question 41

Synthetic Uncouplers

Answer 41

* man made drug * uncouple oxidative phosphorylation *EX. 2,4- dinitrophenol allows e- to move through ETC without pumping protons (produces heat)

Question 42

What is membrane potential

Answer 42

Charge generated across inner mitochondrial membrane

Question 43

Charge of intermembrane space protons | Membrane Potential

Answer 43

+

Question 44

Charge of matrix | Membrane Potential

Answer 44

-

Question 45

What is the proton motive force

Answer 45

Drive H+ across inner membrane to MATRIX **pH gradient + membrane potential** | drives ATP synthase

Question 46

Chemiosmotic Gradient

Answer 46

Occurs when there is different conc of ion across semipermeable membrane ## Footnote protons pumped into intermembrane space genreate 10x gradient = 1 pH difference

Question 47

What are examples of electron donors | high free energy, low redox potential

Answer 47

NADH, FADH2

Question 48

Electron flow direction

Answer 48

LOWER redox potential (HIGHER free energy) --> HIGHER redox potential (LOWER free energy) ## Footnote generates chemiosmotic gradient

Question 49

What moelcule has high redox potential/final acceptor

Answer 49

O2