Chapter 04 – Metabolism, Cellular Respiration & Protein Synthesis

30 vocabulary flashcards covering metabolism, energy, cellular respiration pathways, ATP dynamics, carbohydrate storage, and key molecular biology concepts such as DNA replication, transcription, translation, and mutations.

Metabolism

The sum of all chemical reactions occurring in the body.

Cellular Metabolism

The sum of all chemical reactions occurring within a single cell.

Anabolism

Metabolic reactions that build small molecules into larger ones and require energy.

Catabolism

Metabolic reactions that break larger molecules into smaller ones and release energy.

Energy (biological)

The capacity to do work; common forms include heat, light, sound, electrical, mechanical, and chemical.

Cellular Respiration

A process that transfers energy from molecules (e.g., glucose) and makes it available as ATP for cellular use.

ATP (Adenosine Triphosphate)

The cell’s usable form of energy; composed of adenine, ribose, and three phosphate groups.

ADP (Adenosine Diphosphate)

ATP after it loses its terminal phosphate group.

Phosphorylation

The addition of a phosphate group to ADP to regenerate ATP; requires energy from cellular respiration.

Glycolysis

Anaerobic breakdown of glucose into two pyruvic acid molecules, producing a net gain of 2 ATP and high-energy electrons.

Citric Acid Cycle (Krebs Cycle)

Aerobic pathway in the mitochondria that oxidizes acetyl CoA, generates CO₂, releases high-energy electrons, and synthesizes 1 ATP per cycle.

Electron Transport Chain

Series of mitochondrial enzymes that use high-energy electrons to produce most of the cell’s ATP and form water with oxygen.

Aerobic Reaction

A metabolic reaction requiring oxygen and responsible for most ATP production.

Anaerobic Reaction

A metabolic reaction that does not require oxygen and produces little ATP.

Products of Cellular Respiration

Carbon dioxide, water, ATP (≈40% of energy), and heat (≈60% of energy).

Acetyl CoA

A 2-carbon molecule formed from pyruvic acid that enters the citric acid cycle.

Oxaloacetic Acid

A 4-carbon molecule that combines with acetyl CoA to begin the citric acid cycle, forming citric acid.

Glycogen

Polymer of glucose stored mainly in liver and muscle cells for energy reserve.

DNA (Deoxyribonucleic Acid)

Double-helix molecule storing genetic instructions for protein synthesis.

DNA Replication

Process during interphase that produces an exact copy of DNA for daughter cells.

Transcription

Synthesis of an RNA sequence complementary to a DNA template.

mRNA (Messenger RNA)

RNA molecule that carries genetic code from DNA to ribosome.

tRNA (Transfer RNA)

RNA that brings specific amino acids to the ribosome during protein synthesis.

Translation

Process at the ribosome where mRNA code is converted into an amino-acid sequence to build a protein.

Genetic Code

The set of three-base mRNA codons that specify particular amino acids.

Mutation

A change in DNA sequence that can be harmless, harmful, or rarely advantageous.

Genome Variation (0.1%)

Portion of human DNA sequence that differs among individuals, influencing traits or having no effect.

Dystrophin

Protein whose gene mutation causes Duchenne muscular dystrophy, leading to muscle weakness.

HIV-Resistant Mutation

A genetic change that produces an incomplete cell receptor, providing protection against HIV infection.

High-Energy Electron Carrier

Molecules generated in glycolysis and the citric acid cycle that deliver electrons to the electron transport chain.