Concise Summary on Mitochondria and Chloroplasts

Mitochondria and Chloroplasts

• Energy Conversion: Both organelles are crucial for energy conversion in cells.
• Structure Similarity: Contain extensive membranes facilitating energy harnessing.

Evolution of Mitochondria and Chloroplasts

• Endosymbiotic Theory: Evolved from engulfed prokaryotes in ancestral eukaryotic cells.
• Genetic Material: Both organelles possess their own DNA.

Mitochondria Structure

• Shape & Size: Cylindrical, size ranges from $0.5-1 ext{μm}$.
• Membranes:
  • Outer Membrane: Smooth; contains transport proteins (porins).
  • Inner Membrane: Highly folded (cristae); generates ATP using embedded proteins.
• Compartments: Includes intermembrane space and mitochondrial matrix, housing enzymes, ribosomes, and mitochondrial DNA.

Energy Production in Mitochondria

• Fuel Sources: Uses pyruvate and fatty acids; oxidizes acetyl CoA through citric acid cycle.
• Electron Transport Chain (ETC): Electrons are transferred through a series of proteins, creating a proton gradient used for ATP synthesis through ATP synthase.

Proton Gradient and Chemiosmosis

• Proton Pump: Moves hydrogen ions, creating a gradient that powers ATP formation.
• Chemiosmosis: Protons drive ATP production by rotating ATP synthase like a molecular motor.

Chloroplast Structure and Function

• Similar Arrangement: Comprised of outer and inner membranes enclosing the stroma and thylakoids.
• Photosynthesis Process: Converts light energy into chemical energy, producing glucose and oxygen from water and carbon dioxide.

Photosynthesis Overview

• Light Reactions: Use sunlight to split water, generating ATP and NADPH.
• Calvin Cycle: Utilizes ATP and NADPH to convert CO2 into glucose.

Key Reactions

• Light Reactions: 2H2O + 2NADP + 3ADP + 3Pi ightarrow O2 + 2NADPH + 3ATP
• Dark Reactions: 6CO2 + 18 ATP + 12 NADPH ightarrow C6H{12}O6 + 6H_2O + 18 ADP + 18 Pi + 12 NADP
• Overall Photosynthesis Reaction: 6CO2 + 6H2O
  ightarrow C6H{12}O6 + 6O2