Metabolism and Nutrition in Cells

Overview

• All living organisms perform metabolism to acquire energy.
• Focus on understanding components of nutrition related to cell composition.
• Cells have selectively permeable membranes for transport of necessary building blocks.

Transport Mechanisms

• Review of unicellular organism strategies for material transport.
• Different strategies for nutrient acquisition.

Bioenergetic Principles

• Law of Conservation of Energy: Energy cannot be created or destroyed.
• Law of Entropy: Disorder tends to increase in a system.
• Free Energy: Determines the spontaneity and rate of reactions, requiring catalysts (enzymes) for biological relevance.

Metabolism

• Fundamental process involving electron movement.
• Involves redox reactions, donation, and receiving of electrons in covalent bonds.

Metabolic Pathways

• Focus on glycolysis, citric acid cycle, and the electron transfer chain.
• Compare aerobic vs anaerobic pathways.
• Discussion on biosynthesis vs catabolic processes.

Nutrition and Molecule Classification

• Inorganic Molecules: Do not have both carbon and hydrogen (e.g., CO2, O2).
• Organic Molecules: Contain both carbon and hydrogen (e.g., methane, glucose).

Essential Nutrients

• Macronutrients: Required in large amounts (e.g., carbohydrates, lipids, proteins, nucleic acids).
  • "CHOMPS" acronym (Carbon, Hydrogen, Oxygen, Nitrogen, Phosphorus, Sulfur).
• Micronutrients: Required in small amounts but crucial (e.g., ions like potassium, calcium, sodium).
  • Includes prosthetic groups and coenzymes (e.g., iron in the electron transport chain).

Transport Systems

• Simple Transport System: Uses proton-motor force to bring in substrates like lactose.
• Group Transport: Common in bacteria, involves phosphorylation during sugar uptake.
• ABC Transport System: Involves protein intermediates for indirect phosphorylation, used for vitamins and lipids.

Transport Events

• Uniport: Single substrate moved in one direction.
• Antiport: Two substrates moved in opposite directions.
• Symport: Two substrates moved in the same direction.

Conclusion

• Understanding transport mechanisms and nutrient acquisition is fundamental to studying cellular metabolism and bioenergetics.