3.10 Carbohydrate, Fat, and Protein Metabolism

Adipocytes

Cells specialized for triglyceride synthesis and storage; fat cells

Adipose Tissue

Tissue composed largely of fat-storing cells

Beta Oxidation

Series of reactions that generate hydrogen atoms (for oxidative phosphorylation) from breakdown of fatty acids to acetyl CoA

Essential Amino Acids

Amino acids that cannot be formed by the body at all (or at a rate adequate to meet metabolic requirements) and so must be obtained from diet

Gluconeogenesis

Formation of glucose by the liver or kidneys from pyruvate, lactate, glycerol, or amino acids

Glycerol 3-Phosphate

Three-carbon molecule that combines with fatty acids to form triglyceride

Glycogen

Highly branched polysaccharide composed of glucose subunits; major carbohydrate storage form in body

Glycogenolysis

Glycogen breakdown to glucose

Keto Acid

A class of breakdown products formed from the deamination of amino acids

Negative Nitrogen Balance

Net loss of amino acids in the body over any period of time

Oxidative Deamination

Reaction in which an amino group (-NH2) from an amino acid is replaced by oxygen to form a keto acid

Positive Nitrogen Balance

A period in which there is a net gain of nitrogen (amino acids) in the body

Proteases

Enzymes capable of breaking peptide bonds in proteins

Proteolysis

The process whereby peptides and proteins are cleaved into smaller molecules, by the actions of specific enzymes (proteases)

Transamination

Reaction in which an amino acid amino group (-NH2) is transferred to a keto acid, the keto acid thus becoming an amino acid

Urea

Major nitrogenous waste product of protein breakdown and amino acid catabolism