Photosynthesis and Cellular Respiration     BIOLOGY 12 Photosynthesis and Cellular Respiration

PHOTOSYNTHESIS

Chloroplast Review

Chloroplast Review

Chloroplast Review thylakoids – system of interconnected flattened membrane sacs forming a separate compartment within the stroma of a chloroplast stroma – the protein-rich semiliquid material in the interior of a chloroplast grana – stacks of thylakoids (singular – granum) lumen – space inside the thylakoid discs

Photosynthesis life on Earth is solar powered photosynthesis is comprised of two sets of reactions : light reactions (the “photo” part) Calvin cycle reactions (the “synthesis” part) summary equation: 6CO2 + 6H2O + solar energy  C6H12O6 + 6O2

Photosynthesis - Light Reactions occurs in the thylakoids takes place only in the presence of light they capture energy chlorophyll absorbs light energy  becomes temporarily energized Summary: water is split light energy is converted to chemical energy in the form of two compounds, which will power the Calvin cycle: NADPH (nicotinamide adenine dinucleotide phosphate): a source of energized electrons ATP: the energy currency of cells light reactions release oxygen, and produce no carbohydrate

Photosynthesis - Calvin Cycle occurs in the stroma takes place in the presence or absence of light converting CO2 into carbohydrates requires ATP (produced by the light reactions) Summary: these are synthesis reactions that use NADPH and ATP to reduce CO2 they produce carbohydrate

Photosynthesis Review Questions 1. What is the purpose of the Calvin Cycle? 2. Where does the cell get its energy to perform these reactions? 3. What is the final product? 4. Why is carbon dioxide necessary?

Cellular Respiration

Cellular Respiration - Aerobic the enzymatic breakdown of glucose (C6H12O6) in the presence of oxygen (O2) to produce cellular energy (ATP) one glucose molecule is broken down into a total of 36 ATP molecules three phases: glycolysis Kreb’s cycle (in the mitochondria) Electron Transport Chain (in the mirochondria) summary equation: C6H12O6 + 6O2  6H2O + 6CO2 + ATP

Cellular Respiration: Glycolysis occurs in the cytoplasm anaerobic net yield of 2 ATP per glucose molecule

Cellular Respiration: Kreb’s cycle also called the Citric Acid cycle occurs in the mitochondria aerobic net yield of 2 ATP

Cellular Respiration: Electron Transport Chain (ETC) occurs on the cristae of the mitocondria aerobic majority of all ATP is produced here (32 ATP)

Cellular Respiration – Anaerobic cellular respiration that occurs in the absence of oxygen is called anaerobic cells that undergo anaerobic respiration, still progress through glycolysis, but not through the Kreb’s cycle or the ETC fermentation extends glycolysis with extra reactions, so that glycolysis can keep running and keep producing small amounts of ATP fermentation comes in two types: • lactic acid fermentation • alcohol fermentation

Cellular Respiration – Anaerobic occurs in the cytoplasm anaerobic net yield of 2 ATP per glucose molecule