Chapter 4 Cellular Respiration GCA Mr. Cobb

Cellular respiration Food (glucose) into ATP Not “breathing” It can be either aerobic or anaerobic Aerobic – require oxygen Anaerobic – does not require oxygen

3 Stages of Aerobic Cellular Respiration Glycolysis Preparation Step & Citric Acid Cycle (Kreb’s Cycle) Electron Transport

Glycolysis 1 st step in aerobic or anaerobic Location: cytoplasm of cell Glucose 2 Pyruvic Acid molecules This process does not require Oxygen. Total energy made is 4 ATP, but 2 is needed to start the rxn. 2 ATP is extra. What is made? 2 NADPH, 2 ATP, 2 Pyruvic Acids

Glycolysis glucose  pyruvate

Glycolysis GlucosePyruvic acid Pyruvic Acid

Aerobic O 2 required Release H 2 O and CO 2 and energy Remember that cellular respiration is the opposite of photosynthesis. C 6 H O 2 6 CO H 2 O + ATP

Aerobic Respiration Glycolysis is 1 st step and in both aerobic or anaerobic respiration 2 Steps in Aerobic Respiration: 2. Citric Acid Cycle or Krebs Cycle 3. Hydrogen and Electron Transport System

Cellular Respiration Flowchart (aerobic) Glucose (C 6 H ) + Oxygen (0 2 ) Glycolysis Krebs Cycle Electron Transport Chain Carbon Dioxide (CO 2 ) + Water (H 2 O) + ATP

Citric Acid Cycle (Krebs) 2 Pyruvic acids from glycolysis diffuses into the mitochondria. Pyruvic acid is turned into acetyl CoA and CO 2 is released. One glucose molecule makes the cycle turn twice Chemical rxns in Mitochondria Products: 6 NADH, 2 FADH 2, 2 ATP and 4 CO 2

Krebs cycle pyruvate  acetyl CoA & CO 2

Citric Acid Production The Krebs Cycle Section 9-2 Mitochondrion

H+ and e- transport molecules: 1) NADH 2)FADH 2 

Electron Transport NADH and FADH 2 from Krebs Cycle are pumped by electron energy across the inner membrane (cristae) and creates a concentration difference. The H ions come back across through the ATP synthase and create ATP. Oxygen (from what we breathe in) comes in and binds to the H ions to make water.

Electron Transport 32 ATP Water is made from the Hydrogen and Oxygen.

Electron Transport Mitochondria * two membranes - outer - inner (folded)

Animation 31/krebs.html

ELECTRON TRANSPORT CHAIN

matrix H+H+H+H+ H+H+H+H+ H+H+H+H+ H+H+H+H+ H+H+H+H+ H+H+H+H+ Mitochondria H+H+H+H+ H+H+H+H+ NADH H+H+H+H+ FADH 2 e-e- H+H+H+H+ H+H+H+H+ e-e- H+H+H+H+

Electrons * passed across inner membrane * their energy gradually decreases H + * energy used to transport H + into the intermembrane space.Oxygen * the final electron acceptor H + H 2 O. * joins with H + to produce H 2 O. If there is no oxygen, the electron chain stops. because there is no way to release electrons. electrons

matrix H+H+H+H+ H+H+H+H+ H+H+H+H+ H+H+H+H+ H+H+H+H+ H+H+H+H+ Mitochondria H+H+H+H+ H+H+H+H+ NADH H+H+H+H+ FADH 2 e-e- H+H+H+H+ H+H+H+H+ e-e- H+H+H+H+

What happens when there is no oxygen to accept the electrons? * glycolysis done * then fermentation in cytoplasm 2 kinds 1)lactic acid 2)ethanol

26 Products of Fermentation

fermentation 0 ATP Just takes e-& H+ off NADH so glycolysis can continue

Alcoholic Fermentation After glucose broken down to pyruvate, then pyruvate broken down to CO 2 and ETHANOL.

Alcoholic Fermentation by bacteria & yeast used to make bread, alcohol,

Lactic Acid fermentation By human muscle cells & bacteria Used to make cheese, yogurt, sour kraut

If you work anaerobically, fermentation occurs in your muscles lactic acid builds up results in muscle soreness