The Big Picture

Photosynthesis

  • Photosynthesis:process by which plants convert light energy into chemical energy

  • Key components: chlorophyll, sunlight, water, carbon dioxide

  • Two stages: light-dependent reactions, light-independent reactions (Calvin cycle)

  • Produces: glucose (energy source for plants), oxygen (released as byproduct)

  • Importance: basis of food chain, oxygen production, carbon dioxide absorption

Calvin Cycle

  • Location: Stroma of chloroplasts

  • Purpose: To produce glucose from CO2

  • Steps: Carbon fixation, Reduction, Regeneration of RuBP

  • Enzyme: Rubisco

  • Products: G3P (glyceraldehyde-3-phosphate)

  • ATP and NADPH from light reactions are used

  • Occurs in light-independent reactions

Formula for Photosynthesis:

6CO2 + 6H2O + light energy → C6H12O6 + 6O2

This equation represents the process where carbon dioxide, water, and light energy are converted into glucose and oxygen by plants during photosynthesis.

Light Reactions

  • Light reactions occur in the thylakoid membranes of chloroplasts.

  • They involve photosystem I and II, electron transport chain, and ATP synthase.

  • Light energy is absorbed by chlorophyll to excite electrons.

  • Water is split to release oxygen, protons, and electrons.

  • Electrons move through the transport chain, generating ATP and NADPH.

Electron Transport Chain

  • ATP production: Generated through oxidative phosphorylation

  • Mitochondrial location: Inner mitochondrial membrane

  • Electron carriers: NADH and FADH2

  • Complexes involved: I, II, III, IV

  • Final electron acceptor: Oxygen

ATP Synthase

  • ATP synthase is an enzyme complex found in the inner mitochondrial membrane.

  • It is responsible for producing ATP from ADP and inorganic phosphate during oxidative phosphorylation.

  • ATP synthase consists of two main components: F1, which protrudes into the mitochondrial matrix, and Fo, embedded in the membrane.

  • Protons flow through Fo, driving the rotation of a rotor that causes conformational changes in F1, leading to ATP synthesis.

  • This enzyme plays a crucial role in cellular energy production and is essential for various biological processes.

Cellular Respiration

  • Key: Formula for Cellular Respiration

  • Value: C6H12O6 + 6O2 -> 6CO2 + 6H2O + ATP

  • Key: Reactants

  • Value: Glucose and Oxygen

  • Key: Products

  • Value: Carbon Dioxide, Water, and ATP

  • Key: Importance

  • Value: Generates energy for cell functions

  • Process that converts glucose into ATP

  • Three main stages: glycolysis, Krebs cycle, electron transport chain

  • Glycolysis occurs in cytoplasm, Krebs cycle in mitochondria

  • Electron transport chain generates most ATP

  • Oxygen is final electron acceptor in aerobic respiration

Glycolysis

  • ATP investment phase: Glucose -> Glucose-6-phosphate

  • Energy payoff phase: Glyceraldehyde-3-phosphate -> Pyruvate

  • Enzyme: Hexokinase, Phosphofructokinase, Pyruvate kinase

  • ATP produced: 2 ATP

  • Location: Cytoplasm

Krebs Cycle

  • Location: Takes place in the mitochondria

  • Purpose: Generates energy in the form of ATP

  • Steps: Acetyl-CoA combines with oxaloacetate to form citrate

  • Products: ATP, NADH, FADH2, CO2

  • Regulation: Controlled by feedback inhibition

Fermentation

  • Definition: Process of converting sugars into alcohol or acids

  • Types: Alcoholic fermentation, Lactic acid fermentation

  • Importance: Production of alcoholic beverages, bread, yogurt

  • Microorganisms involved: Yeast, Bacteria

  • Conditions: Anaerobic environment, Optimal temperature and pH