Kreb's Cycle

These flashcards cover key concepts and terms related to the Krebs cycle and oxidative phosphorylation as part of cellular respiration.

Krebs cycle (Citric Acid Cycle)

A series of chemical reactions used by all aerobic organisms to generate energy through the oxidation of acetate.

Acetyl CoA

A highly reactive molecule that begins the Krebs cycle.

Oxaloacetate

A 4-carbon compound that combines with Acetyl CoA to start the Krebs cycle.

oxalacetate + acetyl CoA =

citrate (6 carbon)

CoA is released

step 2

H2O released and added

Isocitrate formed

step 3

Isocitrate to alpha-ketoglutarate (5 carbon)

1 C lost through CO2 release

NADH produced

this step is rate limiting

step 4

Alpha-ketoglutarate to succinyl CoA (4 carbon)

1 C lost through CO2 release, NADH produced

step 5

Succinyl CoA to succinate (4 carbon)
Produces ATP/GTP

substrate level phosphorylation

step 6

Succinate to fumarate (4 carbon)
FADH2 produced

embedded in the inner mitochondrial membrane

step 7

Fumarate to malate (4 carbon)
Water is added

step 8

Malate to oxaloacetate (4 carbon) NADH produced

regenerates oxaloacetate

products of krebs cycle

2 ATP

6 NADH

2 FADH2

mnemonic for kreb’s cycle

Citrate Is Kreb’s Starting Substrate For Making Oxaloacetate