MCAT Biology

A comprehensive introduction to key biological concepts tested on the MCAT, focusing on cellular processes, genetics, and the integration of biological systems.

Cell Structure and FunctionGenetics and InheritanceBiological Molecules
Cellular Respiration and MetabolismMolecular Genetics and Gene ExpressionHuman Body Systems Integration
Genetic Testing and Personalized MedicineBiotechnology in Everyday LifeDisease Prevention and Vaccination
Active Recall and Spaced RepetitionCritical Reading and Data InterpretationTime Management and Pacing
Cell Structure and F...Genetics and Inherit...Biological MoleculesCellular Respiration...Molecular Genetics a...Human Body Systems I...Genetic Testing and ...Biotechnology in Eve...Disease Prevention a...Active Recall and Sp...Critical Reading and...Time Management and ...
Advanced Topics

Cellular Respiration and Metabolism

How Cells Harvest and Use Energy

Energy is essential for life, and cells extract it through metabolism. The main process for generating cellular energy is cellular respiration.

Stages of Cellular Respiration

  1. Glycolysis: Glucose is broken down in the cytoplasm, producing ATP and pyruvate.
  2. Krebs Cycle (Citric Acid Cycle): Pyruvate enters mitochondria, releasing electrons and more ATP.
  3. Electron Transport Chain: Electrons generate a proton gradient, driving ATP synthesis.

The overall equation is: \[ C_6H_{12}O_6 + 6O_2 \rightarrow 6CO_2 + 6H_2O + \text{ATP} \]

Metabolic Pathways

Catabolism breaks down molecules for energy, while anabolism builds new molecules.

Clinical Impact

Understanding metabolism helps explain diseases like diabetes, where energy extraction from glucose is impaired.

Key Formula

\[C_6H_{12}O_6 + 6O_2 \rightarrow 6CO_2 + 6H_2O + \text{ATP}\]

Examples

  • Muscle cells increase respiration during exercise to meet energy demands.

  • Mitochondrial disorders affect energy production, leading to fatigue.

In a Nutshell

Cellular respiration is how cells convert food to usable energy.

Key Terms

ATP
Adenosine triphosphate, the energy currency of the cell.
Glycolysis
The first stage of cellular respiration, breaking down glucose.
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Molecular Genetics and Gene Expression
Cellular Respiration and Metabolism - MCAT Biology Content | Practice Hub