Metabolism Basics and Energy Currency

Vocabulary flashcards covering key metabolic terms, reactions, and molecules discussed in the lecture notes.

Anabolism

Metabolic pathway that builds larger molecules from smaller ones, storing energy in newly formed bonds.

Catabolism

Metabolic pathway that breaks down large molecules into smaller units, releasing energy from broken bonds.

Dehydration Synthesis

An anabolic reaction in which a water molecule is removed to form a new covalent bond between subunits.

Exergonic Reaction

A chemical reaction that releases energy, often driving coupled endergonic processes.

Endergonic Reaction

A chemical reaction that requires an input of energy to proceed, such as most anabolic reactions.

Monosaccharide

A single-sugar molecule; basic building block for carbohydrates like disaccharides and polysaccharides.

Disaccharide

A carbohydrate formed when two monosaccharides are joined via dehydration synthesis.

Lipid

Hydrophobic biomolecule; examples include fats formed from glycerol and fatty acids via dehydration synthesis.

Glycerol

Three-carbon backbone molecule that bonds with fatty acids to form triglycerides.

Fatty Acid

Long hydrocarbon chain with a carboxyl group; bonds to glycerol to form lipids.

Peptide Bond

Covalent bond linking amino acids, created by dehydration between a carboxyl and an amino group.

Amino Acid

Protein monomer containing a central carbon, amino group (NH2), carboxyl group (COOH), hydrogen, and side chain.

Carboxyl Group

Functional group –COOH; contributes an –OH in peptide bond formation.

Amino Group (NH2)

Functional group –NH2; donates a hydrogen in peptide bond formation.

Polysaccharide

Large carbohydrate polymer (e.g., starch, glycogen, cellulose) composed of many glucose units.

Glucose

Six-carbon sugar serving as the primary fuel for cellular respiration.

Cellular Respiration

Series of catabolic pathways that convert glucose to ATP, releasing CO₂ and H₂O.

Adenosine Triphosphate (ATP)

Cell’s energy currency; three phosphate groups store high-energy bonds used to power reactions.

Adenosine Diphosphate (ADP)

ATP after one phosphate is removed; can be re-phosphorylated to regenerate ATP.

Acetyl CoA

Two-carbon molecule derived from pyruvate; enters the Krebs (citric acid) cycle.

Krebs Cycle (Citric Acid Cycle)

Catabolic pathway in mitochondria that oxidizes Acetyl CoA, releasing energy and intermediates for biosynthesis.

Citrate

First intermediate of the Krebs cycle; can be diverted for fatty acid and sterol synthesis.

Alpha-Ketoglutarate

Krebs cycle intermediate that can be withdrawn to produce amino acids and nucleotides.