Cellular Respiration

Cellular Respiration

What is Cellular Respiration? • Step-by-step breakdown of high-energy glucose molecules to release energy • Takes place day and night in all living cells • Occurs in stages, controlled by enzymes C6H12O6

Where does it occur? • In the Cell • Cytoplasm • Mitochondrion • Outer Membrane • Inner Membrane

Aerobic respiration Occurs in the presence of oxygen When chemically breaking down glucose completely, this process releases large amounts energy Anaerobic respiration Usually occurs when there is no oxygen available When partially breaking down glucose, this process releases a very small amount of energy. Different types of Cellular Respiration

Stage 1: Glycolysis • means "splitting sugars"….6 carbon glucose is split into two 3 carbon molecules (pyruvate) • Occurs in the cytoplasm of cells • With or Without O2not required (anaerobic) • Some ATP produced • Net yield = 2 ATPs

The Krebs Cycle(a.k.a. citric acid cycle) • Occurs in the mitochondria • O2 required (aerobic) • CO2 (waste) • Some ATP produced • Net yield = 2 ATPs

SUMMARY OF THE KREBS CYCLE 6 NADH GLYCOLYSIS 2 FADH2 CoA Krebs cycle CO2 acetyl coenzyme A 2 ATP electron transport chain 1. citric acid oxaloacetic acid NAD+ NADH NADH NAD+ 2. CO2 6. a-ketoglutaric acid malic acid 3. CO2 FADH2 FAD+ NADH NAD+ ADP 5. a-ketoglutaric acid derivative 4. succinic acid ATP

Electron Transport Chain • series of electron carriers in the membrane of the mitochondria • Occurs in the inner membrane of mitochondria • O2 required (aerobic) • A lot of ATP produced • Net yield = 32 ATPs Krebs Cycle

A. Cytoplasm of the cell A. Mitochondrion A. Mitochondrial membrane Cellular RespirationReview…... Q. Where does each Stage occur? • 3 Stages: • Stage 1: Glycolysis • O2 not required (anaerobic) • Some ATP produced • Stage 2: Krebs Cycle • O2 required (aerobic) • Some ATP produced • Stage 3: Electron Transport System • O2 required (aerobic) • Much ATP produced 2 ATPs 2 ATPs 32 ATPs

products reactants GLYCOLYSIS glucose 2 ATP Insert 1 Glucose 2 energy tokens 2 NADH GLYCOLYSIS cytosol mitochondrion (ATP) glucose derivatives - carbon dioxide 2 NADH 2 energy tokens carbon dioxide - KREBS CYCLE KREBS CYCLE 6 NADH - - 2 ATP 2 FADH2 - 32 energy tokens - - ELECTRON TRANSPORT CHAIN ELECTRON TRANSPORT CHAIN - 32 ATP Oxygen Water

Chemical Equations • C6H12O6 + 6O2 6H2O + 6CO2 + ATP Or in other words…. • Oxygen combines with glucose to convert it into energy • Releasing carbon dioxide and water as waste products. • glucose + oxygen carbon dioxide + water + lots of heat energy

Anaerobic Respiration • Occurs if there is a lack of oxygen available for aerobic respiration • Glucose is incompletely broken down • In this type of respiration a lot less energy is produced and most of it is lost as heat.

Lactic Acid Formed mainly by animal muscle cells Occurs in some unicellular organisms Glucose lactic acid + a tiny amount of heat energy OR Alcoholic Fermentation Yeast cells, Bacteria Glucose alcohol + carbon dioxide + a tiny amount of heat energy Anaerobic Energy Production: Fermentation C6H12O6 lactic acid + tiny amount of energy

Summary: Aerobic & Anaerobic • Similarities: • Glucose is broken down. • Carbon dioxide is released. • Energy is liberated. • Differences:

Venn Diagram • Use notes to make a venn diagram of similarities and differences between aerobic and anaerobic respiration

mitochondrion GLYCOLYSIS KREBS CYCLE inner membrane ELECTRON TRANSPORT CHAIN inner compartment 32 ATP H2O O2 outer compartment outer compartment ATP SYNTHESIS H+ H+ H+ H+ H+ H+ H+ H+ H+ H+ inner membrane H+ H+ H+ H+ H+ H+ H+ H+ H+ H+ H+ H+ H+ H+ H+ H+ H+ H+ H+ H+ H+ H+ H+ NADH H+ ATP synthesis NAD+ 2 H+ + 1/2 O2 ADP + P inner compartment H2O ATP ELECTRON TRANSPORT CHAIN

Cellular Respiration