Nutrition, Metabolism and Energy Balance

Vocabulary flashcards based on Chapter 24: Nutrition, Metabolism, and Energy Balance from the provided lecture notes.

Nutrient

Substance in food for growth, maintenance, and repair.

Kilocalories (kcal)

Unit for measuring the energy value of foods.

Essential nutrients

Nutrients that must be provided by the diet; cannot be synthesized by the liver.

Carbohydrates

Fuel for energy, mainly from plant sources; includes sugars and fibers.

Lipids

Fats that help absorb fat-soluble vitamins and serve as a major energy source.

Proteins

Macromolecules essential for structure and function in the body.

Vitamins

Organic compounds crucial for metabolism, often acting as coenzymes.

Minerals

Inorganic elements needed for various body functions and structures.

Metabolism

Biochemical reactions in cells involving nutrients.

Anabolism

Synthesis of large molecules from smaller ones.

Catabolism

Breakdown of complex structures into simpler ones.

Cellular respiration

Process by which food fuels are broken down to capture energy in the form of ATP.

Glycolysis

The metabolic pathway that converts glucose into pyruvic acid, yielding ATP.

Krebs cycle

Also known as the citric acid cycle, where acetic acid is oxidized for energy.

Electron transport chain

Series of proteins in the mitochondrial membrane that facilitate oxidative phosphorylation.

Oxidation

Loss of electrons or hydrogen atoms; associated with the release of energy.

Reduction

Gain of electrons or hydrogen atoms; associated with the storage of energy.

ATP (Adenosine Triphosphate)

Energy currency of the cell, powering various biochemical processes.

Glycogenesis

The formation of glycogen from glucose.

Glycogenolysis

The breakdown of glycogen into glucose.

Gluconeogenesis

The formation of glucose from non-carbohydrate sources.

Lipogenesis

The synthesis of triglycerides from excess glucose.

Lipolysis

The breakdown of fats into fatty acids and glycerol.

Cholesterol

A lipid that is an essential component of cell membranes and a precursor for steroid hormones.

Beta oxidation

The metabolic process of converting fatty acids into acetyl CoA.

Acetyl CoA

Key intermediate in metabolism that enters the Krebs cycle.

NAD+

A coenzyme that acts as an electron carrier in metabolic processes.

FAD

A coenzyme involved in redox reactions during cellular respiration.

Hydrogen atoms

Atoms that are involved in redox reactions and energy transfer processes.

Dehydrogenases

Enzymes that catalyze the removal of hydrogen atoms in oxidation reactions.

Oxidative phosphorylation

Process by which ATP is produced using the electron transport chain and chemiosmosis.

Substrate-level phosphorylation

Direct transfer of a phosphate group to ADP to form ATP.

ATP synthase

Enzyme that generates ATP from ADP and inorganic phosphate.

Fatty acids

Building blocks of lipids that can be oxidized for energy.

Glycerol

A component of triglycerides that can be converted into glucose.

Pyruvic acid

The end product of glycolysis, which can enter the Krebs cycle.

Ketone bodies

Byproducts of lipid metabolism that can be used for energy when glucose is low.

Lactic acid

Product of anaerobic metabolism of glucose in the absence of oxygen.

Urea

Compound formed during amino acid deamination, excreted in urine.

Amino acids

Building blocks of proteins, necessary for protein synthesis.

NH3 (Ammonia)

Toxic byproduct of amino acid metabolism that is converted to urea.

Oxaloacetic acid

A 4-carbon molecule that combines with acetyl CoA to start the Krebs cycle.

Transamination

Process where an amino group is transferred from one amino acid to a keto acid.

Oxidative deamination

Removal of an amino group from an amino acid, producing ammonia.

Glycogen phosphorylase

Enzyme that catalyzes the breakdown of glycogen to glucose-6-phosphate.

Hexokinase

Enzyme that catalyzes the phosphorylation of glucose to glucose-6-phosphate.