Lipid and Carbohydrate Metabolism

These flashcards cover key vocabulary related to lipid and carbohydrate metabolism, which includes definitions of various molecules, metabolic pathways, and hormones involved in energy regulation.

Serum Lipoproteins

Transport proteins that carry cholesterol and triglycerides; consist of a core of cholesterol and triglycerides, and a coat of proteins and phospholipids.

Chylomicrons

A type of lipoprotein that transports dietary fats from the intestines to other locations in the body.

VLDL

Very Low-Density Lipoproteins that transport triglycerides from the liver to tissues. “Bad cholesterol”

LDL

Low-Density Lipoproteins that carry cholesterol to tissues but can lead to plaque buildup in arteries. “Bad cholesterol”

HDL

High-Density Lipoproteins that help remove cholesterol from cells and take it back to the liver. “Good cholesterol”

Phospholipid

A class of lipids that are a major component of all cell membranes, with a hydrophilic head and hydrophobic tails.

Triglyceride

An ester formed from glycerol and three fatty acids, serving as a primary form of stored energy.

Amino acids

The building blocks of proteins that can travel easily in the blood.

Energy transfer from glucose

The process of converting glucose to ATP via glycolysis and the citric acid cycle.

Glucose Catabolism

The chemical breakdown of glucose to produce energy in the form of ATP.

Glycolysis

The metabolic pathway that converts glucose into pyruvate.

• Inputs: Glucose, 2\times ATP (for energy investment), 2\times NAD+.
• Outputs: 2\times Pyruvate, Net 2\times ATP, 2\times NADH.

NADH

Reduced nicotinamide adenine dinucleotide; an energy carrier produced in cellular respiration.

FADH2

Reduced flavin adenine dinucleotide; another energy carrier in cellular respiration.

Citric Acid Cycle (Krebs Cycle)

A series of reactions in the mitochondrial matrix that generates ATP, NADH, and FADH2 from acetyl-CoA.

Oxidative Phosphorylation

The process of producing ATP using the electron transport chain and chemiosmosis.

Electron Transport Chain

A series of protein complexes in the mitochondrial inner membrane that transfer electrons and generate ATP.

Chemiosmotic Mechanism

The process of ATP production driven by a proton gradient across the mitochondrial membrane.

Lipolysis

The breakdown of lipids to release fatty acids and glycerol for energy.

Beta Oxidation

The process by which fatty acids are broken down in the mitochondrial matrix to produce acetyl-CoA.

Insulin

A hormone produced by the pancreas that regulates glucose levels and promotes nutrient storage.

Glucagon

A hormone that raises blood glucose levels by promoting glycogen breakdown and glucose release from the liver.

Leptin

A hormone produced by adipose tissue that helps regulate energy balance by inhibiting hunger.

Ghrelin

A hunger hormone produced in the stomach that stimulates appetite.

Peptide YY (PYY)

A hormone released by the L cells of the GI tract that inhibits appetite.

Glucose-Dependent Insulinotropic Peptide (GIP)

A hormone with a role in insulin signaling, released in response to eating.

Hypothalamus

A brain region involved in hunger regulation and energy homeostasis.

Absorptive State

The period when the body is absorbing nutrients post-meal, characterized by insulin dominance.

Postabsorptive State

The period when the body is not absorbing nutrients, dominated by glucagon and counter-regulatory hormones.