Cellular Respiration What is Cellular Respiration Stepbystep breakdown

Cellular Respiration

What is Cellular Respiration? • Step-by-step breakdown of highenergy glucose molecules to release energy • Takes place day and night in all living cells • Occurs in stages, controlled by enzymes C 6 H 12 O 6

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

Different types of Cellular Respiration • 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.

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 O 2 not required (anaerobic) • Some ATP produced • Net yield = 2 ATPs

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

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

Electron Transport Chain • series of electron carriers in the membrane of the mitochondria • Occurs in the inner membrane of mitochondria • O 2 required (aerobic) • A lot of ATP produced • Net yield = 32 ATPs

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

products reactants Insert 1 Glucose GLYCOLYSIS - - -- KREBS CYCLE - 2 energy tokens (ATP) glucose GLYCOLYSIS 2 ATP 2 NADH on l i r o d tos hon y c toc i m 2 NADH 2 energy tokens 6 NADH 2 FADH 2 glucose derivatives carbon dioxide KREBS CYCLE carbon dioxide 2 ATP 32 energy tokens - ELECTRON TRANSPORT CHAIN Oxygen 32 ATP Water

Chemical Equations • C 6 H 12 O 6 + 6 O 2 6 H 2 O + 6 CO 2 + 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.

Anaerobic Energy Production: Fermentation • Lactic Acid § Formed mainly by animal muscle cells § Occurs in some unicellular organisms • Alcoholic Fermentation § Yeast cells, Bacteria § Glucose alcohol + carbon dioxide + a tiny amount of heat energy § Glucose lactic acid + a tiny amount of heat energy OR C 6 H 12 O 6 lactic acid + tiny amount of energy

Summary: Aerobic & Anaerobic • Similarities: § Glucose is broken down. § Carbon dioxide is released. § Energy is liberated. • Differences: Aerobic respiration Anaerobic respiration Lots of energy released Little energy is released Water is the end product Lactic Acid or alcohol is the end product Glucose is completely broken down Glucose is partially broken down Is dependent on oxygen Is not dependent on oxygen

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

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