LAST LECTURE! - DEC2

Examination Focus on Saturated Fats
- Understanding of C12 and C16 saturated fats is key.
- Will not focus on general saturated fat concepts.
Oxidation Process Overview
- Describes a pathway without austenation.
- Consists of a series of four linked reactions.
- Purpose: Reduces carbon chain length by 2 carbons per cycle.
- Each cycle produces:
- 1 NADH
- 1 FADH2

Example: C16 Fatty Acid Oxidation
- Calculation involves the processes of:
- Counting acetyl CoA produced
- Counting NADH
- Counting FADH2
- For C16:
- Acetyl CoA produced = 8
- Number of cycles = n/2 - 1 = 16/2 - 1 = 7
- Number of NADH = 7
- Number of FADH2 = 7
- Total ATP produced calculation:
  - ATP from Acetyl CoA into TCA cycle: 8 times 12 = 96
  - ATP from NADH: 7 times 2.5 = 17.5
  - ATP from FADH2: 7 times 1.5 = 10.5
  - Therefore, Total = 96 + 17.5 + 10.5 = 124.
Example: C12 Fatty Acid Oxidation
- For C12, similar calculations yield different numbers:
- Acetyl CoA produced = 6, which leads to:
  - Total ATP from C12 = (6 * 12) + (5 * 2.5) + (5 * 1.5) = Total ATP.

Comparison of ATP yield between Glucose and Fatty Acids
- C6 Glucose undergoing glycolysis produces 40 ATP.
- C6 Fatty acid (such as palmitate) produces 46 ATP.
- This indicates that on a pure carbon basis, fats yield more energy compared to carbohydrates.
Difference in Metabolic Pathways
- Glycolysis and TCA system for glucose.
- Fatty acid oxidation links into similar pathways, specifically breaking down fatty acids by beta-oxidation.

Keto Diet and Energy Utilization
- Occurs during low carbohydrate intake, fasting, and starvation.
- Initial loss of weight due to caloric shortage leads to decreased energy expenditure.
- As glucose levels fall, the body shifts to fat oxidation and produces ketone bodies for energy.
Fatty Acid Breakdown via Beta-Oxidation
- Produces Acetyl CoA and subsequently ketone bodies.
- Key components produced are NADH and FADH2.
- Acetyl CoA is sent to the TCA cycle for additional ATP production, but not directly transferred outside of liver cells due to reactivity.

A ketone body serves as a transport form of Acetyl CoA.
- Produced when the liver converts Acetyl CoA into acetoacetate, beta-hydroxybutyrate, and acetone under low glucose conditions.
- Acetoacetate and beta-hydroxybutyrate can travel in the blood to tissues such as the brain, heart, and muscle.
- Upon reaching the tissues, they convert back to Acetyl CoA for use in the TCA cycle, yielding ATP.
Specific Ketone Bodies:
- Acetoacetate: Results from Acetyl CoA losing its CoA.
- Beta-Hydroxybutyrate: Formed through the reduction of acetoacetate.
- Acetone: Byproduct exhaled via breath, not contributing to Acetyl CoA formation.

Amino Acids Basics
- Consist of an amine group, central carbon, carboxylic acid, and variable (R) group.
Nitrogen Removal Process
- Toxic nitrogen must be removed from amino acids.
- Two main reactions:
- Transamination: Transfers an amine from an amino acid to an alpha-keto acid (common: pyruvate).
  - Enzyme involved: Alanine aminotransferase (ALT) or Aspartate aminotransferase (AST).
- Oxidative Deamination: Produces ammonia from the amino acid.
Urea Cycle
- Ammonia produced enters the urea cycle where it's converted into urea.
- Involves formation of citrulline and argininosuccinate, which splits into arginine and fumarate.
- Ultimately leads to urea formation.

Expect questions on:
- Calculation of ATP produced from different pathways.
- Relationships between glucose and fatty oxidation yields.
- Understanding ketogenesis and its relevance in metabolic states.
- Details of amino acid metabolism, nitrogen removal, and the urea cycle.
Assessments of methodologies will reflect on accumulated knowledge on metabolism and bioenergetics. Key focus should be on understanding integration of all metabolic pathways covered, including glycolysis, TCA cycle, fatty acid oxidation, and amino acid metabolism.