Cellular Respiration Quiz

Cellular Level of Organization

• The human body is organized in a hierarchical structure, starting with cells.
• Cellular respiration and its steps.
• Cell membrane structure and function, including selective permeability.
• Various cellular transport mechanisms.
• Effects of isotonic, hypotonic, and hypertonic solutions on cells.
• Factors that contribute to resting membrane potential.

Mitochondria

• Function: Mitochondria are the "powerhouses" of the cell, as they use glucose to create energy in the form of ATP.
• Structure:
  • Outer membrane: The outer layer of the mitochondrion.
  • Cristae: Folds in the inner membrane that increase surface area for cellular respiration.
  • Intermembrane space: Space between the inner and outer membrane.
  • Matrix: Fluid-filled area within the inner membrane that contains mitochondrial DNA and ribosomes.

Metabolism Review

• Metabolism encompasses all biochemical processes within a living organism, including anabolism (building up molecules) and catabolism (breaking down molecules).
• Anabolism is the process of building up molecules, which requires energy.
• Catabolism is the process of breaking down molecules, which releases energy.

ATP Review

• ATP structure: ATP is composed of adenine, ribose, and three phosphate groups.
• ATP energy release: Energy is released when a phosphate group is removed from ATP, forming ADP (adenosine diphosphate).
• ATPase: An enzyme that catalyzes the hydrolysis of ATP, releasing energy.
• Phosphorylation: The addition of a phosphate group to a molecule, often done to restore ATP from ADP.

Two Types of Phosphorylation

• Substrate Level Phosphorylation:
  • A phosphate group is directly transferred from a substrate to ADP.
  • Does not rely on ATP synthase.
  • Takes place in glycolysis and the Krebs cycle.
• Oxidative Phosphorylation:
  • Occurs after the electron transport chain.
  • Uses ATP synthase to produce ATP.
  • Happens after the electron transport chain.

When is ATP Made in the Body?

• Aerobic Respiration: Requires oxygen, yielding energy, carbon dioxide and water.
• Anaerobic Respiration: Does not require oxygen, producing less energy and lactic acid.

Overall Equation for Cellular Respiration

• Glucose + Oxygen → Carbon dioxide + Water + Energy (ATP)

Cellular Respiration as a REDOX Reaction

• Oxidation: Loss of electrons (in glucose).
• Reduction: Gain of electrons (in oxygen to produce water).
• REDOX reactions are coupled oxidation and reduction reactions.

Two Carrier Molecules

• NAD+ and FAD+ are electron carriers.
• They accept and transport electrons during cellular respiration, eventually delivering them to the electron transport chain.
• They become reduced to NADH and FADH2 when they accept electrons.

Other Cellular Respiration Facts

• Metabolic Pathway: The series of steps that break down carbohydrates during cellular respiration.
• Exergonic: Cellular respiration is an exergonic process.
• Catabolic: It breaks down larger molecules into smaller ones like CO2 and H2O.

Stages of Cellular Respiration

• Glycolysis: The breakdown of glucose into pyruvate (anaerobic).
• Krebs Cycle: The oxidation of acetyl CoA to produce ATP, NADH, FADH2 (aerobic).
• Electron Transport Chain: Electrons from NADH and FADH2 are passed along a chain of proteins, generating ATP (aerobic).

Key Points of Glycolysis

• Location: Occurs in the cytoplasm.
• Type: Anaerobic process.
• Start: Glucose.
• End: Two molecules of pyruvate.
• ATP Production: Net gain of 2 ATP.

Where does the pyruvate go after glycolysis?

• If oxygen is present: Pyruvate enters the mitochondria becoming oxidized to acetyl coA
• If oxygen is not present: The process becomes fermentation, producing lactic acid.

Fermentation

• Lactic acid fermentation (in muscles) or in alcoholic fermentation (in yeast).
• Produces only 2 ATP per glucose, instead of 30 - 38.

Krebs Cycle Summary

• Location: Mitochondrial matrix.
• Type: Aerobic process.
• Input: 2 pyruvate.
• Output: 2 ATP, 6 NADH, 2 FADH2, 2 CO2 per glucose molecule.

Electron Transport Chain

• Location: Inner mitochondrial membrane
• Function: Hydrogen ions and electrons are passed along to carry energy from NADH, FADH2, into ATP synthases.
• Transmembrane potential: A difference in charge across the inner membrane, created by pumping hydrogen ions.
• Hydrogen ion flow: Hydrogen ions flow back into the matrix through ATP synthase, driving ATP synthesis (chemiosmosis).

How does H+ translate to ATP?

• Four hydrogen ions are required to produce one molecule of ATP.
• 10 hydrogen ions from NADH equal 2.5 molecules of ATP.
• 6 hydrogen ions from FADH2 equal 1.5 molecules of ATP.

Cellular Respiration Summary (ATP Yield)

• Total ATP Yield: ~30-38 ATP molecules per glucose molecule. The exact total is variable, depending on cell types and efficiency.

Helpful Videos

• Videos discussing cellular respiration are referenced. (Specific videos are cited)

Genetic Mutations Affecting Protein Structure

• Mutations in genes can lead to various diseases.
• Example mitochondrial diseases. (Specific genetic diseases and their effects are cited).

Electron Transport Chain Poisons

• Poison examples.
• How poisons can block the electron transport chain and affect ATP production.

Cyanide Poisoning

• Source of cyanide (smoke inhalation or other exposures).
• Symptoms of cyanide poisoning (from inhalation).
• Treatment for cyanide poisoning.

Almonds and Cyanide

• Some almonds are known to contain cyanide.

Quick detour on Transmembrane Potential

• Explanation of what transmembrane potential is.

Test your knowledge on the processes of cellular respiration including glycolysis, the Krebs cycle, and the electron transport chain. This quiz covers ATP yield, fermentation, and the role of oxygen in these metabolic pathways.