Lecture on Cellular Energetics

Introduction

• Instructor: Mrs. Jones from AP Bio Penguins
• Session: Live review of Unit 3 - Cellular Energetics
• Resources Available:
  • Daily reviews on Instagram
  • 374-page review guide on Weebly
  • FRQ (Free Response Question) Fridays
  • 120 quizzes/games on Weebly
  • Review PowerPoints available

Overview of Cellular Energetics

1. Key Concepts:
   • Free Energy (Gibbs Free Energy)
   • Enzymes
   • Cellular Respiration
   • Photosynthesis

Free Energy

• Definition: Energy available to do work
• Reactions:
  • Endergonic Reactions: Require energy input; non-spontaneous
  • Exergonic Reactions: Release energy; spontaneous
• Equation: Delta G = Delta H - T * Delta S (change in enthalpy, temperature in Kelvin, change in entropy)*

Enzymes

• Role: Biological catalysts that speed up chemical reactions by lowering activation energy
• Properties:
  • Proteins with specific structures
  • Not consumed by reactions
  • Do not change Gibbs free energy
• Types of Inhibition:
  • Competitive Inhibition: Competes with substrate for active site
  • Non-Competitive Inhibition: Binds to a different site, changing enzyme shape

Cellular Respiration

• Steps: Glycolysis, Krebs Cycle, Oxidative Phosphorylation
• Glycolysis:
  • Occurs in the cytosol
  • Converts glucose to pyruvate
  • Produces 2 ATP and 2 NADH
• Krebs Cycle:
  • Occurs in mitochondrial matrix
  • Produces CO2, NADH, FADH2, and GTP (ATP equivalent)
• Oxidative Phosphorylation:
  • Occurs in mitochondrial cristae
  • Consists of Electron Transport Chain (ETC) and Chemiosmosis
  • Produces ATP by establishing a proton gradient

Photosynthesis

• Stages: Light Reactions and Calvin Cycle
• Light Reactions:
  • Occur in thylakoid membranes
  • Use water and light to produce ATP and NADPH
  • Oxygen is a byproduct
• Calvin Cycle:
  • Occurs in the stroma
  • Uses CO2, ATP, and NADPH to produce glucose

Practice Questions and Concept Applications

• Multiple Choice: Understanding reaction processes, energy use
• Free Response Questions: Describe biological roles, experimental setups, advantages of aerobic respiration

Additional Topics

• Photosynthesis Efficiency: C3, C4, and CAM plants adaptations
• Experimental Design: Negative controls, glucose's role in respiration

Conclusion

• Reminders:
  • Daily reviews and resources on social media
  • No additional questions from students

This summary provides an overview of key concepts in cellular energetics, focusing on how energy is utilized and produced in biological systems. The session covered critical processes such as cellular respiration and photosynthesis, emphasizing the role of enzymes and energy transformations.