Cellular Respiration Chapter 9

Interest Grabber Feel the Burn Do you like to run, bike, or swim? These all are good ways to exercise. When you exercise, your body uses oxygen to get energy from glucose, a six-carbon sugar. Section How does your body feel at the start of exercise, such as a long, slow run? How do you feel 1 minute into the run; 10 minutes into the run? 2.What do you think is happening in your cells to cause the changes in how you feel? 3.Think about running as fast as you can for 100 meters. Could you keep up this pace for a much longer distance? Explain your answer.

Sunlight powers life Autotrophs – Photosynthesis – Producers Heterotrophs – Consumers Cellular respiration- converts energy into cell fuel (ATP

Why do living things need food? provides living things with the chemical building blocks they need to grow and reproduce. Source of raw materials for making new molecules source of energy

What do cells do with food? Cells gradually release energy from glucose and other food compounds in the form of ATP.

ATP Most of the energy from cell respiration is converted into ATP ATP is a substance that powers most cell activities. Energy in phosphate bonds

Cellular Respiration Process that releases energy by breaking down glucose to make ATP at each stage 3 Steps – Glycolysis – Kreb’s cycle – Electron Transport Chain Formula

Cellular Respiration 3 stages: 1.Glycolysis –the breaking of glucose into pyruvate 2.Kreb’s Cycle–pathway which converts pyruvate 3.Electron Transport Chain- coverts NADH into ATP

The 3 steps of cellular respiration 1. Glycolysis 2. Kreb’s cycle 3. Electron Transport Chain Each stage captures some of the chemical energy available in food molecules and uses it to produce ATP.

Glucose Glycolysis Krebs cycle Electron transport Fermentation (without oxygen) Alcohol or lactic acid Chemical Pathways Section 9-1

Glycolysis Occurs in cytoplasm Does not require oxygen Net gain of ATP = 2 Molecule of glucose is broken in half to two pyruvate molecules (then goes into mitochondria)

Cellular Respiration

End of Glycolysis 90% of the energy of glucose still has not been used The energy is stored in the electrons of pyruvic acid

Cellular Respiration Stage Two(Aerobic): Production of ATP Krebs Cycle reactions that produce energy-storing molecules (NADH and ATP) Pyruvate  citric acid In mitochondria Carbon dioxide given off

Citric Acid Production Figure 9–6 The Krebs Cycle Section 9-2 Mitochondrion

Mitochondria The matrix where 3- carbon pieces that came from carbohydrates are broken down to (CO 2 and water) The cristae is where ATP is made

Stage 3- ETC- Electron transport chain Hot potato-electrons Uses high energy electron to convert NADH in to ATP Oxygen gets the “hot potato” to make water

Figure 9–7 Electron Transport Chain Section 9-2 Electron Transport Hydrogen Ion Movement ATP Production ATP synthase Channel Inner Membrane Matrix Intermembrane Space Mitochondrion

Fermentation (anaerobic) When oxygen is not present, gylcolysis follows this pathway (anaerobic) Two types – Alcoholic fermentation – Lactic Acid Fermentation

Alcoholic Fermentation Yeasts and other microorganisms Causes bread to rise Formula

Lactic Acid Fermentation Pyruvic acid can turn to lactic acid so gylcolysis can continue Produced in muscles during exercise when oxygen is used up Muscles continue to make ATP

Alcohol Fermentation Unicellular organisms also go through this process Used in the productions of foods and beverages- cheese, yogurt, sour cream, pickles, alcoholic beverages

Summary MoleculeRole in respiration C 6 H 12 O 6 Broken down in glycolysis = 2 ATP made, pyruvate O2O2 Accepts H+ in ETC, aids in making ATP * Aerobic respiration only H2OH2OMade in ETC, waste product CO 2 Made in Krebs cycle, waste product

Flowchart Section 9-2 Glucose (C 6 H ) + Oxygen (0 2 ) Glycolysis Krebs Cycle Electron Transport Chain Carbon Dioxide (CO 2 ) + Water (H 2 O) Cellular Respiration

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