METABOLISMCATABOLISM ANABOLISM

KNOW THE DIFFERENCECATABOLISM• Exergonic• Reactions such as• Glycolysis• Krebs cycle• The electron transport

chain

ANABOLISM• Endergonic• Reactions such as• Formation of peptide

bonds between amino acids during protien synthesis

• The linkage of glucose monomers to form glycogen

Glucose Catabolism • Cellular respiration• Reactions involved• Glycolysis• The formation of acetyl coenzyme A• The kreb cycle• The electron transport chain

The Fate of pyruvic acid• Anaerobic condition• Is reduced via an anaerobic pathway by

addition of two hydrogen atoms to form lactic acid (LACTATE)

• 2 Pyruvic acid+2NADH+2H+ 2 Lactic acid + 2NAD+

• Aerobic condition

• Pyruvic acid Acetyl CoA• This molecule links, glycolysis which occur in

cytosol and the krebs cycle which occurs in the matrix of mitochondria

Formation of Acetyl CoA• Summary: Pyruvate is degraded and

combined with coenzyme A to form acetyl coenzyme A; hydrogens are released; and carbon dioxide is released.

Pyruvate dehydrgenase

Aerobic Respiration• The Krebs Cycle

• Decarboxylation of pyruvic acid produces one CO2 molecule and one acetyl group linked to CoA (acetyl-CoA).

• NAD is reduced to NADH (2 electrons removed from pyruvate).

Two acetyl-CoA groups are oxidized in the Krebs cycle for each glucose molecule (one six carbon glucose is oxidized to two 3 carbon pyruvic acid molecules, each of which is decarboxylated to produce an acetyl-CoA molecule). 

Electrons are picked up by NAD+ and FAD for the electron transport chain.

From one molecule of glucose, oxidation in the Krebs cycle produces six molecules of NADH, two molecules of FADH2, and two molecules of ATP.Decarboxylation produces six molecules of CO2.

The electron transport chain• Electrons are brought to the electron

transport chain by NADH.• The electron transport chain consists of

carriers, including flavoproteins, cytochromes, and ubiquinones.

• Electrons are passed from one carrier to the next, the energy is used to drive proton pumps.

• The final electron acceptor is irreversibly reduced; it may be oxygen (aerobic) or another inorganic molecule (anaerobic).

Flavin mononucleotide(FMN)Cytocromesb,c1,c,a,a3Iron-sulphur(Fe-S) ceters ELECTRON CARRIERSCopper(Cu) atomsCoenzymes Q

The Chemiosmotic Mechanism of ATP Generation

• Protons being pumped across the membrane generate proton motive force as electrons move through a series of acceptors or carriers.

• Energy produced from movement of the protons back across the membrane is used by ATP synthase to make ATP from ADP and phosphate.

• In eukaryotes, electron carriers are located in the inner mitochondrial membrane; in prokaryotes, electron carriers are in the plasma membrane.