SC

Key Concepts Review

Aerobic and Anaerobic Respiration

  • Aerobic Respiration: Requires oxygen (False statement corrected).
  • Anaerobic Respiration: Does not require oxygen.

G Protein-Coupled Receptors (GPCRs)

  • Energy Source: Uses GTP for signal transduction (not ATP).
  • Cyclic AMP (cAMP): Derivative of ATP; important for cellular communication; formed by cleaving ATP.

Thermodynamic Principles

  • Spontaneous Reactions: Negative ext{ΔG} indicates spontaneity; occur without energy input.
  • Non-Spontaneous Reactions: Positive ext{ΔG} indicates they require energy to reach equilibrium.

Inhibition Mechanisms

  • Feedback Inhibition: Product inhibits enzyme to stop production (Correct answer is A).
  • Competitive vs. Allosteric Inhibition:
    • Competitive Inhibition: Inhibitor binds at the active site.
    • Allosteric Inhibition: Inhibitor binds at the allosteric site, modulating activity.

Redox Reactions

  • Oxidizing Agent: Accepts electrons (not related to oxygen).

Cell Membrane Structure

  • Smooth vs. Rough ER:
    • Rough ER: Continuous with nuclear membrane, synthesizes proteins.
    • Smooth ER: Continuous with rough ER, involved in lipid synthesis and calcium storage.

Hypotonic Solutions

  • Definition: Higher solute concentration inside the cell leads to swelling due to osmosis.
  • Plant Cells: Do not burst due to turgor pressure from the cell wall.
  • Animal Cells: Burst due to lack of a cell wall.

Phospholipid Bilayer

  • Basic structure involves hydrophilic heads and hydrophobic tails; essential for membrane fluidity.
  • Cholesterol Function:
    • At high temperatures: Reduces fluidity by filling in gaps.
    • At low temperatures: Prevents rigidity by introducing kinks.

Signal Transduction Stages

  1. Receive: Ligand binds to receptor.
  2. Transduce: Signal is amplified and transmitted through the cell.
  3. Respond: Cellular response to the signal is executed.

Protein Synthesis and Transport

  • Synthesis: Occurs in the Rough ER.
  • Transport: Via vesicles from the ER to the Golgi apparatus (cis to trans direction).
  • Packaging and Excretion: In Golgi, packaged in vesicles, exocytosed at the trans face.

Calvin Cycle Overview

  1. Carbon Fixation: CO2 is fixed by RuBisCO.
  2. Reduction Phase: Produces G3P from ATP and NADPH.
  3. Regeneration: G3P is used to regenerate substrates.
  • Uses ATP and NADPH generated in light-dependent reactions.