Comprehensive Study Guide: BIOL 1406

Key Concepts Only: No Need to Memorize Every Detail!

1. Cell Structure & Theory

Cell Theory (3 Principles)

  1. All living organisms are composed of one or more cells.

  2. The cell is the basic unit of life.

  3. All cells arise from pre-existing cells.

Cell Size & Diffusion Constraints

  • Cells rely on diffusion to transport nutrients & waste.

  • Smaller cells = higher surface area-to-volume ratio (better efficiency).

Common Features in All Cells

  • Genetic material (DNA/RNA)

  • Cytoplasm (fluid-filled interior)

  • Plasma membrane (selective barrier)

  • Ribosomes (protein synthesis)

2. Prokaryotic vs. Eukaryotic Cells

  • Prokaryotes: No nucleus, simple structure (e.g., bacteria, archaea)

  • Eukaryotes: Have a nucleus & organelles (e.g., plants, animals, fungi)

3. Biological Membranes & Transport

Fluid Mosaic Model

  • Phospholipid bilayer: Selectively permeable, regulates cell environment.

  • Proteins & Cholesterol: Maintain structure & function.

Transport Mechanisms

  • Passive Transport: Diffusion (high → low concentration, no energy needed).

  • Active Transport: Requires ATP (e.g., Na+/K+ pump).

  • Bulk Transport: Endocytosis (into cell), Exocytosis (out of cell).

4. Macromolecules & Biochemistry

  • Carbohydrates: Energy (glucose), storage (starch, glycogen), structure (cellulose).

  • Proteins: Made of amino acids, responsible for structure & enzyme function.

  • Lipids: Fats (energy storage), phospholipids (membranes), steroids (hormones).

  • Nucleic Acids: DNA & RNA (store & transfer genetic info).

5. Enzyme Function & Metabolism

  • Enzymes: Speed up reactions, lower activation energy.

  • Affected by: Temperature, pH, inhibitors.

  • Feedback Inhibition: Prevents waste by stopping unneeded reactions.

6. Cellular Respiration

  • ATP = Cellular Energy Currency

  • Glycolysis (Cytoplasm): Glucose → 2 ATP (Anaerobic)

  • Krebs Cycle (Mitochondria): Makes electron carriers for ETC.

  • Electron Transport Chain (Mitochondria): Produces most ATP using oxygen.

  • Aerobic vs. Anaerobic: Oxygen needed for full ATP production; fermentation occurs without oxygen.

7. Gibbs Free Energy, Redox Reactions, & pH

Gibbs Free Energy (ΔG)

  • ΔG = ΔG(products) - ΔG(reactants)

  • Exergonic (-ΔG): Releases energy (spontaneous).

  • Endergonic (+ΔG): Requires energy input.

Redox Reactions (LEO goes GER)

  • Lose Electrons = Oxidation (energy loss)

  • Gain Electrons = Reduction (energy gain)

  • Electron carriers (NADH, FADH₂): Key in respiration.

pH & Buffers

  • pH scale (0-14): Acids (0-6), Neutral (7), Bases (8-14).

  • Buffers: Stabilize pH (e.g., blood bicarbonate system).

Key Takeaways for Review

✔ Know the key principles, don’t stress over details. ✔ Understand major differences (Prokaryotes vs. Eukaryotes, Aerobic vs. Anaerobic Respiration). ✔ Master transport mechanisms & enzyme function. ✔ Recognize energy flow (ATP, Gibbs Free Energy, Redox). ✔ pH balance & buffers keep biological systems stable.