Overview

This topic examines how cells capture, convert, and use energy to sustain life. It includes the processes of photosynthesis and cellular respiration, as well as the biochemical pathways that synthesize essential molecules from simpler substances.

Key Concepts and Processes

• ATP (Adenosine Triphosphate): The primary energy carrier in cells. It stores energy in high-energy phosphate bonds and releases it to power cellular processes.
• Photosynthesis: The process by which plants, algae, and some bacteria convert light energy, water, and carbon dioxide into glucose and oxygen. Occurs in chloroplasts.
  6CO₂ + 6H₂O + light → C₆H₁₂O₆ + 6O₂
• Cellular Respiration: The process of breaking down glucose in the presence of oxygen to produce ATP. Occurs in mitochondria.
  C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O + ATP
• Aerobic vs. Anaerobic Respiration: Aerobic uses oxygen and produces more ATP; anaerobic occurs without oxygen and produces less ATP, with byproducts like lactic acid or alcohol.
• Chloroplasts and Mitochondria: Organelles responsible for energy transformations—chloroplasts for photosynthesis, mitochondria for respiration.
• Enzymes: Proteins that act as biological catalysts, speeding up chemical reactions without being consumed.
• Metabolism: All chemical reactions within a cell, including catabolism (breaking down molecules) and anabolism (building molecules).
• Biosynthesis: The creation of complex molecules like proteins, nucleic acids, and lipids from simpler compounds using energy (often from ATP).

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