Nutrition and Metabolism

Metabolism: Nutrition

Nutrition

The starting point and basis for all human form and function, providing fuel for energy and raw materials for cells.

Metabolism

The chemical changes that lie at the foundation of form and function, encompassing catabolic and anabolic reactions.

Body Weight

Determined by the body’s energy balance, stable, influenced by hereditary and environmental factors.

Appetite

Regulated by peptide hormones and pathways related to short- and long-term energy needs.

Gut-brain peptides

Chemical signals that communicate hunger and satiety from the gastrointestinal tract to the brain.

Ghrelin

A hormone secreted from the stomach that stimulates hunger.

Peptide YY (PYY)

Hormone secreted by the ileum and colon that signals satiety.

Cholecystokinin (CCK)

Hormone that stimulates bile secretion and suppresses appetite.

Leptin

Hormone secreted by adipose tissue that informs the brain about body fat levels, regulating energy balance.

Insulin

Hormone secreted by the pancreas that helps control blood glucose levels and stimulates fat and glycogen synthesis.

Glycolysis

The process of breaking down glucose to produce 2 ext{ ATP}, occurring in the cytoplasm.

Citric acid cycle (Krebs cycle)

Aerobic metabolic pathway that breaks down acetyl-CoA to produce ext{CO}_{2}, NADH, FADH2, and 2 ext{ ATP}.

Electron transport chain

Sequence of proteins in the mitochondrial membrane that generates 26-28 ext{ ATP} using electrons from NADH and FADH2.

Catabolism

The breakdown of organic substrates to extract energy.

Anabolism

The synthesis of new organic molecules, utilizing energy and building blocks.

Nutrient pool

Collection of organic substrates available for catabolism and anabolism in the body.

BMI (Body Mass Index)

A measure defined as weight in ext{kg} divided by height in ext{meters squared}, used to assess overweight and obesity.

Obesity

Defined as a condition of being over 20 ext{%} above the recommended weight for age, sex, and height.

Calories

Units of energy used to quantify the amount of energy obtained from food.

Macronutrients

Nutrients required in large quantities, including carbohydrates, proteins, and fats.

Micronutrients

Nutrients required in small quantities, including vitamins and minerals.

Fatty acids

Components of lipids that can be broken down for energy or synthesized into other lipids.

Amino acids

Building blocks of proteins, some of which must be obtained from the diet.

Hydration

The process of providing adequate fluid intake to maintain physiological function and health.

Electrolytes

Minerals that conduct electrical charges in the body, essential for numerous bodily functions.

Vitamin A

A fat-soluble vitamin essential for vision health, immune function, and cellular growth.

Vitamin B

A group of water-soluble vitamins that act as precursors to coenzymes, vital for energy metabolism, nervous system function, and red blood cell formation.

Vitamin C

A water-soluble vitamin required for collagen synthesis, antioxidant protection, and immune support.

Vitamin D

A fat-soluble vitamin gained from sunlight and diet that facilitates calcium absorption to maintain healthy bones.

Vitamin E

A fat-soluble vitamin that acts as an antioxidant, protecting cell membranes from oxidative damage.

Vitamin K

A fat-soluble vitamin critical for blood coagulation and the synthesis of proteins involved in bone metabolism.

Ascorbic Acid

The chemical name for Vitamin C, known for its role in preventing scurvy and assisting tissue repair.