PHSC 208, L26

. ox/phos

2 NADH —>

makes ~5 ATP

. ox/phos

(Citric Acid Cycle) 6 NADH —>

makes ~15 ATP

. ox/phos

(Citric Acid Cycle) 2 FADH2 —>

makes 3 ATP

Anaerobic glycolysis yields directly __ ATPs

2

Aerobic glycolysis to Krebs cycle yields directly __ ATPs

4

Mitochondria has __ membranes

2, inner and outer membrane

Outer mitochondrial membrane

porous to small metabolites

EX: lets water or ATP flow in and out

Inner mitochondrial membrane

Citric acid cycle occurs in MITOCHONDRIAL MATRIX

Oxidation is…

a series of removal of electrons from carbohydrates and intermediates

• electrons pass through NADH and FADH2 to the electron transport system

• then ATP synthesis occurs by oxidative phosphorylation

Ultimate proton acceptor in citric acid cycle and oxidative phosphorylation (aerobic respiration)

Oxygen

more positive E° value is

the more likely it steals electrons from something else

• oxygen is very E° positive

NADH + H⁺ +1/2O2 —> NAD⁺ + H2O

A-reduced + B-oxidized <—> A-oxidized + B-reduced

• losing electron= oxidized

• gaining electron= reduced

Example of Redox Reaction

Pyruvate + NADH + H⁺ <—> Lactate + NAD⁺

Standard Reduction Potential

ΔG°’ = -nFE°’

• electrons flow spontaneously from a substance with more negative reduction potential to a substance with a more positive reduction potential

• -ΔG means it will spontaneously occur

A higher reduction potential =

it is more likely for the substance to be reduced

A lower reduction potential=

more likely to act as a reducing agent

Redox Coenzymes (high-energy electron carriers)

NADH, FADH2, NADPH

NADH and NADPH

• co-substrates that bind to enzymes transiently

• highly polar and water soluble

• cannot cross mitochondrial membrane

NADH specifics

• made from glycolysis, TCA cycle, fatty acid oxidation

• makes ATP by oxidative phosphorylation

NADPH

• made from pentose phosphate pathway (PPP)

• reducing agent in anabolic reaction

Where electrons are being accepted or donated from

the blue part i think

FAD (Flavin adenine nucleotide)

• hydrophobic, don’t really move around

• serves as “prosthetic groups”

Key Differences of NAD+/NADP+ vs FAD

NAD+/NADP+:

• binds/releases 2 protons at a time

• bind to enzymes transiently

• highly polar and water soluble

FAD:

• one and two-electron transfers

• prosthetic group in enzymes

• flavin ring system is hydrophobic

iClicker: In the production of acetyl-CoA from pyruvate, how many NADHs, CO2s, and acetyl-CoAs are made from 1 glucose molecule?

2 NADHs, 1 CO2, 1 acetyl-CoA