RespirationI. Introduction

A. What happens to the glucose made by photosynthesis1. Converted to starch for storage2. Is broken down to yield energy

a. cellular respirationII. Cellular respiration: overview

A. All Rxn in which energy is released to support cell lifeB. A controlled process

1. Comparisonsa. Burning wood

1. A Rxn that releases stored energy2. Uncontrolled

a. energy released in a single chemical Rxn

b. WoodHeat + Light

b. Burning food1. A Rxn that release stored energy2. Controlled

a. Energy is released during several stepsb. The product of one Rxn. becomes the reactant in the next

step of the Rxn.3. Cells release energy in a series of steps

C. Cells transfer energy from foodATP1. Food (Starch)Glucose2. Cells transfer energy from glucoseATP

3. ATP Broken down to yield energya. ATP CO2 + H2O + Energy

D. Energy release overview1. Step 1: Food (starch)Glucose2. Step 2: GlucoseATP3. Step 3: ATP CO2 + H2O + Energy

III. Cellular respiration: A detailed lookA. Glycolysis

1. Anaerobic stage of cellular respirationa. Does not require O2

2. Occurs outside the mitochondriaa. Cytosol

3. Glucose 2 pyruvic acid moleculesa. A 3-carbon molecule

4. Energya. 2 ATP molecules are needed to

split glucoseb. 4 ATP molecules formed by

energy released from splitting glucose

c. A net gain of 2 ATPd. 2 NADH molecules released

5. Glycolysis is only 3.5 % efficienta. For every glucose molecule broken down by glycolysis only 3.5%

is converted to energy

B. Aerobic respiration1. Occurs within the mitochondria2. The Pyruvic acid molecules from glycolysis enter the mitochondria

a. Each pyruvic acidacetyl CoA1. 1 NADH released/ pyruvic acid

3. The Krebs Cyclea. Acetyl CoA enters the Krebs cycle

b. Through a series of 5 main steps1. 3 NADH released/ Acetyl CoA2. 1 FADH2 released/ Acetyl CoA3. 1 ATP released/ Acetyl CoA

Remember: For every glucose molecule entering glycolysis, 2 pyruvic acid molecules are created. This in turn creates 2 acetyl CoA molecules. This results in: 2 NADH Pyruvic Acid

6 NADH2 FADH2 Kreb Cycle 2 ATP

For each glucose molecule

4. Electron Transport Chaina. The second stage of aerobic respirationb. Works similar to ETC in photosynthesis

1. For every NADH 3 ATP made2. For every FADH2 2 ATP made

c. Total ATP production 34 ATP

5. How efficient is aerobic respiration?a. 40% efficient

1. For every glucose molecule that enters aerobic respiration, 40% is converted to usable energy!!

b. Comparison1. An automobile is only 25% efficient