chpt 6&7 video from class 9/23

Atp and respiration crash course video notes 9/23/25

Introduction

The speaker discusses energy production in cells and its complexity.
Energy generation is akin to sports and exercise; it involves hard work but yields significant benefits.
Introduces ATP (adenosine triphosphate) as a crucial molecule for energy storage and usage in cells.

Definition: Cellular respiration is the process of deriving energy from food, particularly glucose.
Chemical Formula for Glucose: C6H12O6 (Represents one molecule of glucose)
Reactants of Cellular Respiration: 6 molecules of oxygen (O2).
Products of Cellular Respiration: 6 molecules of carbon dioxide (CO2), 6 molecules of water (H2O), and energy (in the form of ATP).
Importance of ATP: ATP is essential for various cellular functions, including movement, growth, and neural impulses.

ATP is referred to as the currency of biological energy.
Analogy: Energy must be converted to ATP for cellular use, similar to needing U.S. dollars to conduct business in the U.S.
Functions of ATP: Growth, movement, creation of electrical impulses in nerves and brains.

Components of ATP:
- Nitrogenous base: Adenine
- Sugar: Ribose
- Three phosphate groups
Phosphate Group Properties: The three phosphate groups are negatively charged and repel each other, similar to three kids sitting in a row who dislike each other.
Breaking ATP: When one phosphate group is removed, ATP converts to ADP (adenosine diphosphate), and energy is released.
Hydrolysis Process: The reaction where water is used to break down ATP is called hydrolysis.
Explanation of hydrolysis: Hydro means water; lysis comes from the Greek word for 'to separate'.

Overall Yield: One molecule of glucose can yield about 38 molecules of ATP during cellular respiration (though commonly about 29 to 30 ATP).
Stages of Cellular Respiration: Generally described in three stages:
1. Glycolysis
2. Krebs Cycle (Citric Acid Cycle)
3. Electron Transport Chain

Definition: Glycolysis is the breakdown of glucose into two molecules of pyruvate (pyruvic acid).
Process Requires: Investment of 2 ATPs to proceed.
Net Gain: Produces 4 ATPs, yielding a net gain of 2 ATPs, 2 pyruvates, and 2 NADH (energy-rich molecules).
Anaerobic Process: Glycolysis can occur without oxygen (anaerobic).
Fermentation: In the absence of oxygen, pyruvates undergo fermentation to regenerate NAD+, producing byproducts like alcohol in yeasts and lactic acid in human muscles.

Location: Occurs in the mitochondria (the power center of the cell).
Function: Processes pyruvates from glycolysis and produces additional ATP.
Process: One pyruvate is oxidized, releasing CO2 and forming acetyl CoA.
Energy Production: Also generates NADH and FADH2, key molecules for later ATP production.
Cycle Definition: The Krebs cycle is named after Hans Krebs, who described it, and is known for the production of citric acid.
NAD and FAD: These enzymes are crucial in carrying electrons and are associated with B vitamins that help in energy storage.

Main ATP Production: Most ATP is generated in this stage.
Efficiency: Can yield about 34 ATPs per glucose molecule.
Mechanism: Uses NADH and FADH2 to move protons across the mitochondrial membrane, creating a proton gradient.
ATP Synthase Role: Protons return through ATP synthase, driving the production of ATP by combining ADP and phosphate.
Output per Glucose: Summarizes the total ATP yields:
- Glycolysis: 2 ATPs
- Krebs Cycle: 2 ATPs
- Electron Transport Chain: 34 ATPs
- Total: Approximately 38 ATPs per glucose molecule

Highlights importance of cellular respiration in energy production for the body.
Engages the audience to ask questions for further clarification.
Encourages review of the material to reinforce learning.