Anaerobic Respiration and Fermentation

What is the goal of fermentation?

oxidize NADH into NAD+ so glycolysis can continue and produce ATP in the absence of oxygen

What are the two types of fermentation?

Alcoholic fermentation and lactic acid fermentation.

Describe lactic acid fermentation

NADH transfers its electrons to pyruvate to form lactic acid, regenerating NAD+ for glycolysis.

What is the Cori cycle?

A metabolic pathway that converts lactate produced by anaerobic glycolysis back into glucose in the liver via gluconeogenesis, allowing for energy recovery and maintaining blood sugar levels.

What is the first step of alcohol fermentation following glycolysis?

Pyruvate is decarboxylated and loses CO₂, forming Acetylaldehyde

What is the second step of alcohol fermentation following glycolysis?

Acetylaldehyde is reduced to ethanol by NADH, regenerating NAD+.

Obligate aerobe

can only metabolize using aerobic respiration

Obligate anaerobe

can only metabolize using anaerobic respiration; O₂ is toxic

Facultative anaerobes

prefer aerobic respiration, but can perform both anaerobic and anaerobic respiration

Microaerophiles

only perform aerobic respiration, but high O₂ levels are toxic

Aerotolerant organisms

only undergo anaerobic respiration or fermentation, but O₂ is not harmful

Glycogenesis

glucose to glycogen, occurs in the liver

Glycogenolysis

the breakdown of glycogen to glucose, primarily in the liver and muscles.

Beta-oxidation

free fatty acids are converted into Acetyl CoA in the mitochondrial matrix

What is the role of ATP in beta-oxidation?

ATP is invested and activates beta-oxidationto facilitate the breakdown of fatty acids for energy production.

How are free fatty acids transported throughout the body?

Bound to albumin

During lactic acid fermentation, which of the following molecules is reduced?

Pyruvate to lactate