CELLULAR RESPIRATION

RESPIRATION Lab Below is a listing which will help you to prepare for the quiz and lab on this material.

CONTENT TO KNOW:

I. Overview of Respiration - Respiration consists of a series of catabolic reactions which break down molecules to release energy; creates ATP for use by the cell

C6H12O6 + 6O2 ------> 6CO2 + 6H2O

Mitochondria – the organelle in which cellular respiration occurs

II. ATP – adenosine triphosphate – energy “currency” of the cell; readily spendable

• 36 ATP – produced each time one glucose is completely “burned” using aerobic respiration

• ADP + Pi ------> ATP (phosphorylation) - now carries energy

• ATP ------> ADP + Pi (releases energy)

Click Here for an IMAGE of ATP

III. Summary - The 3 Stages of Respiration –

Click Here for an IMAGE of the 3 Stages of Respiration

GLYCOLYSIS – Sugar “lysis” (breaks glucose into two pieces) • End products of glycolysis = 2 pyruvate molecules • Occurs out in the cytoplasm

THE KREBS CYCLE – • all carbons originally in glucose are released as carbon dioxide here • occurs in the mitochondria

ETC (ELECTRON TRANSPORT CHAIN) – electrons are passed down a series of proteins embedded in the mitochondrial membrane; they accept and then release electrons while harvesting energy from them

Reduction - is the gain of electrons Oxidation - is the loss of electrons These reactions are always coupled: hence the term REDOX

• changes NADH into ATP • ETC occurs in the mitochondria

IV. Anaerobic Pathways –

Anaerobic - without oxygen • Lactate (lactic acid) Fermentation (muscle cells can utilize this path) • Alcohol Fermentation – has a decarboxylation step; produces 2 ATP