3.5 - Cellular Respiration

What is the purpose of cellular respiration?

deconstruct glucose by oxidizing to create ATP

Mitochondrion

catabolizes glucose and other metabolites

Outer Membrane

smooth; bean like shape

Inner Membrane

highly folded and convoluted (Cristae)

What does the inner membrane hold?

houses ETC and ATP Synthase

Intermembrane Space

high concentration of protons

Matrix

location of citric acid cycle

Where does Glycolysis occur?

in the cytosol

Glycolysis - Energy Investment

-cell invests 2 ATP to phosphorylate glucose twice

-breaks down into TWO G3P

Glycolysis - Energy Payoff

-NAD+ is reduced to NADH

- phosphate bonds to G3P

-all phosphates are stripped from G3P (each phosphate removed = ATP)

-remainder of G3P is Pyruvate

What is the net result of Glycolysis?

2 ATP, 2 NADH carriers, 2 Pyruvate, H2O waste

What determines if pyruvate can enter the mitochondria?

if oxygen concentration is sufficient

Link Reaction

removes CO2 from Pyruvate and adds CoA

-NAD+ and FAD are reduced

What are the results of Link Reaction?

2 Acetyl CoA molecules, 1 FADH, and 1 NADH

Citric Acid Cycle

metabolizes Acetyl CoA to produce more ATP and electron carriers

What are the results of the Citric Acid Cycle?

6 NADH, 2 FADH2, 2 ATP, CO2 waste

What drops off the electrons at the ETC?

NADH and FADH2

ETC

a series of proteins embeded in the mitochondrial inner membrane

ATP Synthase

facilitated diffusion transport proteins

Oxidative Phosphorylation

electrons go though the ETC, fueling the active transport of protons into the intermembrane space. The protons diffuse back into the matrix via ATP Synthase, creating ATP

How is the proton concentration gradient in the intermembrane space established?

through the electrons running through the ETC

What is drawing electrons through the ETC?

oxygen at the end of the chain

What occurs when electrons reach oxygen?

they join together with two protons to create water

What are products of oxidative phosphorylation?

26-28 ATP and 6 H2O

When does fermentation occur?

when the oxygen concentration is insufficient in the mitochondria

What does fermentation produce in prokaryotic cells?

ethanol and CO2

What does fermentation produce in animals?

lactic acid/lactate

Why is the Cori Cycle insufficient for living?

the liver must give up 6 ATP in the process, causing a net loss of ATP

Where does the Cori Cycle occur?

the liver

Cori Cycle

transforming lactate into glucose to undergo cellular respiration