lecture recording on 11 March 2025 at 18.49.01 PM

Exam Grades and Feedback

• Exam grades have been posted; additional 12 points added to each exam score.

• General observation: exam scores were lower than expected.

• Specific Method for Grading: 12 points added to reach the highest score (to 100%) due to overall low performance.

Importance of Exam Preparation

• For those who did not pass (even with the added points) need to reconsider study strategies.

• If achieved a 'C' grade or lower, similar reflection on study habits is necessary.

• Addressing Study Techniques:

  • Time spent studying, methods of study, utilization of tutoring and office hours.

  • Engagement in class: Are students fully attentive?

  • Importance of asking questions during lectures if material is unclear.

Suggestions for Improvement

• If a student spent significant time preparing and still is not achieving desired results, they are encouraged to discuss their study techniques with the instructor.

• Focus is on improving study strategies to excel in difficult classes in a healthcare career pathway.

Overview of Glycolysis

• Glycolysis: First stage of cellular respiration where glucose is converted into two pyruvic acid molecules.

• Key Points:

  • The glucose molecule is oxidized to pyruvic acid.

  • Redox reactions occur: oxidation (losing electrons) and reduction (gaining electrons).

  • NAD+ is reduced to NADH through the acceptance of electrons.

  • Net production: 2 ATP (4 produced, but 2 consumed).

Pyruvate Oxidation and Krebs Cycle

• When Oxygen is Available:

  • Pyruvic acid is converted to acetyl CoA.

  • The process involves NAD+ being reduced to NADH and release of CO2.

• Acetyl CoA enters the Krebs Cycle, resulting in:

  • Conversion of acetyl CoA to citric acid then further through a series of reactions yielding ATP, NADH, FADH2, and CO2.

  • Cycle produces energy carriers for later stages.

Oxidative Phosphorylation

• Last phase includes two components: Electron Transport Chain (ETC) and Chemiosmosis.

• Electron transport involves NADH and FADH2 delivering electrons, ultimately producing water and ATP.

  • Oxygen acts as final electron acceptor.

• Chemiosmosis involves the flow of protons (H+) to synthesize ATP via ATP synthase.

Energy Yield from Cellular Respiration

• Glycolysis Product: 2 net ATP, 2 NADH, 2 pyruvic acid.

• Pyruvate Oxidation Product: 2 NADH.

• Krebs Cycle Product: 2 ATP, 6 NADH, 2 FADH2.

• Oxidative Phosphorylation: Approx. 28 ATP.

• Total potential yield: 32 ATP per glucose molecule, though this number can fluctuate by efficiency.

Role of Glycogenesis and Glycogenolysis

• In case of excess glucose: stored as glycogen in liver and muscle through glycogenesis.

• When glucose is low: glycogen is broken down to glucose via glycogenolysis.

Role of Lipogenesis and Lipolysis

• Excess glucose can be converted into fat via lipogenesis when glycogen stores are high.

• If energy is needed: triglycerides can be broken down through lipolysis.

Gluconeogenesis

• Occurs when glucose is scarce; formation of glucose from non-carbohydrate sources.

• Important for maintaining blood glucose levels via liver.

• Summary of Important Terms:

  • Glycolysis: Breakdown of glucose.

  • Glycogenesis: Formation of glycogen from glucose.

  • Glycogenolysis: Breakdown of glycogen to release glucose.

  • Gluconeogenesis: Formation of new glucose from non-carb sources.

  • Lipogenesis: Formation of fat from glucose.

  • Lipolysis: Breakdown of fats to release fatty acids.