Citric Acid Cycle Exam/ETC (electron transport chain (oxidative phosphorylation)) #2

Citric acid cycle

location:

PDH complex?

location: mitochondria

PDH complex

purpose: pyruvate (glycolysis) → Acetyl coA → CAC

aerobic metabolism

E1

coenzyme?

inhibition?

activation?

deficiencies?

coenzyme: TPP → requires thiamine (vit B1)

inhibition: phosphorylation (PDH kinase)

activation: dephosphorylation (PDH phosphotase)

deficincies: 1. congenital lactic acidosis

2. vit b1 (thiamine) deficiency

E2

coenzyme?

coenzyme: lipoic acid, COA

associated with arsenic poisioning

E3

coenzyme

requires

inhibition

coenzyme: FAD, NAD+

requires riboflamin (vit b2) + niacin (vit b3)

inhibition: acetyl coa/NADH activates PDH kinase

Electron transport chain

location:

purpose:

diagram?

location: inner mitochondria membrane

purpose: increase ATP production

Electron transport chain by steps

Step 1: NADH/FADH2 produced earlier donate electrons (NADH → complex I) (FADH → complex II)

Step 2: Electrons from both complex I and II are transferred to coenzyme Q, then carried to complex III

Step 3: electrons pass through complex III, protons pumped into intermembrane space, contributes to proton gradient

Step 4: Electrons transferred to cytochrome c and carried to complex IV

Step 5: at complex IV, electrons are passed to oxygen, combined with protons to form water

Step 6: Proton gradient generated drives protons back into matrix through ATP synthase (chemiosmosis)

Step 7: Protons move through ATP synthase, rotate enzyme, catalyzes phosphorylation of ADP → ATP