Chapter 9- Cellular Respiration 1

9.1 A. Harvesting the Energy in Food 1. both producers and consumers undergo cellular respiration to make ATP from glucose a. Cells in plants and animals then use ATP as their main energy supply. 2. The processes of photosynthesis and cellular respiration recycle a common set of chemicals. a. water, carbon dioxide, oxygen, and glucose. 2

Figure 7-3 The products of photosynthesis are the chemical ingredients for cellular respiration, while the products of cellular respiration are the chemical ingredients for photosynthesis. 3

B. Calories: Units of Energy 1.A calorie is the amount of energy required to raise the temperature of 1 gram (g) of water by 1 degree Celsius (°C) By measuring the increase in water temperature and using the definition of a calorie, you can calculate the number of calories in food. 4

C. Relationship of Cellular Respiration to Breathing 1. Cellular respiration is an aerobic process, meaning that it requires oxygen. 2. a cell exchanges two gases with its surroundings a. takes in oxygen and releases carbon dioxide. b. The bloodstream delivers oxygen to cells and carries away carbon dioxide. 5

3. The process of breathing results in the diffusion of these gases between your blood and the outside air. a. This exchange takes place in tiny air sacs in your lungs. b. Movement of oxygen: Inhale  Lungs  air sacs  bloodstream  cell c. Movement of carbon dioxide: cell  blood  air sacs  lungs  exhale 6

4.Overall Equation for Cellular Respiration C 6 H 12 O 6 + 6O 2  6H 2 O + 6CO ATP 7

9.2 Cellular Respiration A. Structure of Mitochondria 1. found in almost all eukaryotic cells. 2. An envelope of two membranes encloses the mitochondrion a. There is a space between the outer and inner membranes. b. The highly folded inner membrane encloses a thick fluid called the matrix. 8

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B. Stage 1: Glycolysis 1. An enzyme-assisted anaerobic process that breaks down: 2ATP + C 6 H 12 O 6  2 pyruvates + 4 ATP 2. A net of two ATP molecules are formed. 3. occurs in the cytoplasm of cells. 10

C. Stage 2: The Krebs Cycle 1. When oxygen is present, pyruvate produced during glycolysis enters a mitochondrion. Step A: 2 pyruvate  CO 2 + NADH + acetyl-CoA 2. After acetyl-CoA is produced the following happens: Step B: acetyl-CoA  ATP + NADH + FADH 2 3. FADH 2 : Electron carrier 1FADH 2  2ATP 4.NADH: An electron carrier 1NADH  3 ATP 5.Occurs in matrix 11

D. Stage 3: The Electron Transport System 1. After the Krebs Cycle, NADH and FADH 2 contain much of the energy that was originally found in the glucose molecule. 2.These molecules pass through an electron transport chain that makes up to 34 molecules of ATP from NADH and FADH 2. 3.Occurs in the inner membrane of the mitochondria (folded! WHY?!) 12

E. Adding up the ATP- 38 ATP molecules 1. Glycolysis produces net gain of two ATP molecules. 2. The Krebs cycle produces two more ATP molecules 3. The ETS produce about 34 more molecules of ATP. 13

9.3 A. Fermentation in Human and animal cells 1. Fermentation follows glycolysis in the absence of oxygen. 2. Fermentation: anaerobic process that recycles NAD + 3. Lactic Acid Fermentation: occurs when pyruvate  lactate + NAD + 4. This is why our muscles get sore and tired when we exercise. 5. Only makes 2 ATP 14

B. Fermentation in Microorganisms 1. Alcohol Fermentation occurs when pyruvate  ethanol + CO 2 2. This is how we make wine and bread. 3. Only makes 2 ATP 15