Biology Pyruvate Oxidation, Kreb's Cycle and ETC

Where does Pyruvate Oxidation take place?

Pyruvate Oxidation takes place in the matrix and cristae folds of the mitochondria

Where does Kreb's Cycle take place?

Kreb's Cycle takes place in the matrix and cristae folds of the mitochondria

Where does Electron Transport Shuttle take place?

Electron Transport Shuttle takes place in the matrix and cristae folds of the mitochondria

Which cells are Mitochondria found?

The mitochondria exists in Eukaryotic Cells

What are the products of one pyruvate molecule?

1 Carbon Dioxide, 1 NADH, and 1 Acetyl CoA

How does NADH transfer electrons into the mitochondria?

NADH are transported across the inner mitochondrial membrane using two "shuttling" system

Malate-Aspartate Shuttle

More efficient shuttle that occurs in the liver, kidney or heart

Glycerol-Phosphate Shuttle

Less efficient shuttle that occurs in the brain or skeletal muscle

Pyruvate Oxidation Steps

1. Decarboxylation of pyruvate to an aldehyde
2. NAD+ reduced to NADH + H
3. Coenzyme A added to pyruvate to form Acetyl CoA

Coenzyme A

A large organic molecule that binds to active sites that assists with pyruvate oxidation

What are the products of Kreb's Cycle

Each acetyl CoA produces 2 carbon dioxide, 1 FADH2, 3 NADH, and 1 ATP (2 Acetyl CoA!)

What are FAD and NAD molecules

FAD and NAD are a type of electron acceptors that transfer electrons across the mitochondria

What is a Electron Transport Chain

The ETC is a series of electron carriers that accept electrons from NADH and FADH2

How do electrons move across the ETC

Electrons move across the ETC in a series of REDOX reactions

What is the importance of oxygen in the ETC

Oxygen is highly electronegative, final electron acceptor at the end of ETC (Forms H20 at the end)

Which side of the ETC is more concentrated with H

The intermembrane space has a higher concentration of H creating a positive charge

ETC Component: Complex 1

2 electrons from NADH are transferred to Complex 1 and protons are pumped across the membrane

ETC Component: Q

2 electrons are transferred from complex 1 to Q (is a lipid soluble and can move within bilayer)

ETC Component: Complex 3

2 Electrons are transferred from Q to Complex 3, and protons are pumped across the membrane

ETC Component: Cyt C

1 Electron are transferred from Complex 3 to Cyt C, carries 2 electrons but only transfers 1 (a mobile component on the surface of the membrane)

ETC Component: Complex 4

1 Electron are transferred from Cyt C to Complex 4, and protons are pumped across the membrane

ETC Component: O2

Final electron acceptor and produces a water molecule at the end

ETC Component: Complex 2

2 electrons are transferred from FADH2 to Complex 2, (does not pump protons!)

What is the difference between FADH2 and NADH during the ETC

FADH2 starts at Complex 2 instead of Complex 1 which results in 1 less ATP than NADH

Electrochemical Gradient

Electrons in NADH and FADH2 powers protein pumps to create a electrochemical gradient

Driving Force of ETC

Extremely electronegative oxygen drives the ETC process

Chemiosmosis

The force which pulls H+ into the matrix due to the electrochemical gradient creating a proton-motive

ATP Synthase

Large protein that uses energy from H+ ions to bind ADP and a phosphate group together to produce ATP

Oxidative Phosphorylation

The production of ATP using energy derived from the redox reactions

Facilitated Diffusion of Protons

Use of transport protein (ATP Synthase)

Diffusion of Protons

Movement of molecules down a gradient, requires no energy (Electrochemical Gradient)

ATP Conversions

ATP = ATP
NADH = 3 ATP
FADH2 = 2 ATP

Substrate-Level Phosphorylation

Direct ATP formation through phosphate transfer from substrate to ADP (Glycolysis and Krebs)