Pyruvate Oxidation and CAC - BIO 183

chemiosmosis

• requires ATP synthase and a proton (H+) gradient

• protons diffuse down concentration gradient, powers ATP synthase embedded in mitochondrial inner membrane

• chemiosmosis accounts for 90% of ATP produced during aerobic cellular respiration

• occurs across from the inner membrane space across the inner membrane of mitochondria

• occurs across thylakoid membrane of chloroplasts during photosynthesis

Preparatory Step: Oxidation of pyruvate

• in euk cells, if oxygen is present, the 2 pyruvate molecules enter mitochondria

• pyruvate goes through the 2 membranes of mitochondria; the 1st through a non specific channel, then a pyruvate specific channel to reach the matrix

oxydation of pyruvate

• pyruvate is converted to Acetyl CoA befor entering CAC

• → CO2 is released

• → pyruvate is oxidized

• → transferring an electron to NADH (NAD+ is reduced)

• Acetyl group from former pyruvate molecule is attached to CoA

INPUTS

• 2 pyruvate, 2 NAD+

• 2 coenzyme A

OUTPUTS

• 2Co2

• 2NADH

• 2 acetyl CoA

Citric Acid Cycle occurs in mitochondrial matrix

• Step 1 - acetyl group from acetyl CoA is transferred to oxaloacetate to form citrate

• through series of reactions (1 cycle):

• → citrate is oxidized

• → 2 Co2 released

• →1 GTP or ATP produced

• The final product of Citric Acid Cycle is oxaloacetate

Outputs per glucose from Glycolysis, Pyruvate Oxidation, & CAC