Cellular Respiration

Learning Objectives Explain the relationship between calorie and Calorie Write the balanced chemical equation for cellular respiration

Where does the energy that living things need come from? Food!

Why do you need to eat food? Energy for daily activities. Cells in your body convert chemical energy (glucose) into ATP

Chemical Energy & Food Food serves as a source of energy. Our cells use molecules from fats, proteins and carbohydrates as food energy.

How is energy from food measured? Energy in food is converted to heat The amount of heat needed to raise the temperature of 1 gram of water by 1 degree Celsius = 1 calorie 1000 calories = 1 Calorie

What is the relationship between the green box and blue box? Reactant Product Reactant Product

Cellular Respiration Cellular respiration is the process that releases energy by breaking down glucose in the presence of oxygen.

Cellular Respiration Cellular respiration occurs in the mitochondria

Mitochondrial Structure Outer membrane – encloses the mitochondria Inner membrane – folds many times to make cristae Cristae – site of ATP production Matrix – fluid contained in the mitochondria

The Balanced Chemical Equation for Cellular Respiration Glucose oxygen water carbon energy dioxide C6H12O6 + 6 O2 6 H20 + 6 CO2 + ATP (Reactants) (Products)

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Learning Objectives Describe the 3 steps of cellular respiration Describe the role of ATP in cellular activities

3 Steps of Cellular Respiration Step 1 - Glycolysis - break down glucose, make some ATP Step 2 - Krebs Cycle - series of reactions that produce energy-storing molecules, some ATP. Step 3 - Electron Transport Chain - produce large amounts of ATP.

3 Parts of Cellular Respiration Electron Transport Chain Krebs Cycle Glycolysis Krebs Cycle Electron Transport Chain

Glycolysis (occurs in cytosol) Glycolysis is the process in which one molecule of glucose is broken in half, producing 2 pyruvic acid + 2 NADH + net gain of 2 ATP. NADH goes to the electron transport chain.

Pyruvate Respiration (in cytosol) Glycolysis (in cytosol) Aerobic Fermentation Respiration (in cytosol) (in mitochondria) some ATP O2 available (aerobic) O2 not available (anaerobic) No ATP mucho ATP

Fermentation (occurs in the cytoplasm under anaerobic conditions) Two types Alcoholic Fermentation Lactic Acid Fermentation

Alcoholic Fermentation Pyruvic Acid + NADH Alcohol + CO2 + NAD+

Lactic Acid Fermentation Pyruvic Acid + NADH Lactic Acid + NAD+

Pyruvate Respiration (in cytosol) Glycolysis (in cytosol) Aerobic Fermentation Respiration (in cytosol) (in mitochondria) O2 available (aerobic) O2 not available (anaerobic)

Aerobic Respiration (occurs in the mitochondria under aerobic conditions) The energy-releasing pathways within cells require oxygen, which is why we breath.

Mitochondria Structure Pyruvate (three carbon molecule from glycolysis) is broken down to CO2 and H2O in the matrix. ATP is made in the cristae. ATP powers most cellular activities.

Krebs Cycle 2 ATP - used for cellular activities 6 CO2 expelled in breath Pyruvate from glycolysis is used to make CO2, NADH, ATP and FADH2. Energy-carrying molecules transfer energy to next stage (Electron Transport Chain).

Electron Transport Chain The electron transport chain uses the high energy electrons from the Krebs cycle to convert ADP into ATP.

Let’s Review

How much ATP is made per glucose molecule?

The Big Picture Glucose Cell Membrane Cytosol

How Cells Obtain Energy YouTube Video How Cells Obtain Energy

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