Cells and Energy

On your “Heart and Lung Model” Write the word alveoli: Write down what has to happen in the alveoli. From your homework, write Pathway of Air,then the pathway for air to follow. Write down diffusion and describe how Oxygen moves in lungs, body cells

Cells use energy to: Move Change shape Reproduce React to their environment Metabolize (manufacture and repair parts of cell) Transport food and nutrients Expel waste

Divide your notes into 4 sections: Energy-ATP and evidence for the products for cellular respiration Aerobic Respiration Anaerobic Respiration The of cellular respiration

Cellular Respiration compared to combustion In the energy and evidence for reactants part of your notes: What has to happen for the candle to burn? What are the products given off when the candle burns? What happens when the student breathes into the test tube? What are the products for someone breathing?

ATP: What the cell needs for energy! Adenosine Triphosphate Energy currency Deliver energy to wherever is needed in a cell ATP breaks down into ADP releasing one phosphate group and energy The released energy is able to drive cell’s activities

Cellular Respiration: why the body cells need Oxygen A stepwise series of reactions that break down complex molecules into carbon dioxide and water, releasing energy in the process

Chemical Equation C 6 H 12 O 6 + 6O 2  6CO 2 + 6H 2 O + 36 ATP What is our evidence that Carbon dioxide and water are given off during cellular respiration?

Two forms of cellular respiration: –Aerobic Respiration –Anaerobic Respiration

Aerobic Respiration Cellular Respiration in the presence of oxygen (also called oxidative respiration)

Occurs in 3 stages: 1.Glycolysis  one glucose molecule is split into two 3-carbon products (pyruvic acid) releases 2 ATP molecules Occurs in cytoplasm Takes ATP to start reaction, but produces more ATP than it uses

Occurs in 3 stages: 2.Krebs Cycle  breaks the 3- carbon products (pyruvic acid) down into carbon dioxide, releases 2 ATP molecules Occurs in mitochondria

Occurs in 3 stages: 3. Electron Transport Chain  each H atom is separated into an electron (-) and a proton (H+). The H+ combines with O 2 molecules forming water (H 2 O). 36 ATP molecules are released. * Occurs in mitochondria

How much energy is produced in aerobic respiration? For every ONE glucose molecule: 2 ATP + 2 ATP + 36 ATP = 40 ATP 2 ATP used to make pyruvic acid 2 ATP used to move pyruvic acid into the mitochondria 40 ATP – 2 ATP – 2 ATP = 36 ATP

Anaerobic Respiration Cellular Respiration which occurs when there is little or no oxygen

Occurs in 2 stages: 1.Glycolysis  same as in aerobic respiration. Produces 2 ATP molecules.Produces 2 ATP molecules.

Occurs in 2 stages: 2. Fermentation  cells convert pyruvic acid (the 3-carbon molecule from glycolysis) into lactate another 3- carbon molecule. Lactate cycles back into glycolysis and the cycle occurs again. This continues until oxygen is present. –Each fermentation cycle produces 2 ATP molecules.

Types of Fermentation Lactic Acid Fermentation  The anaerobic pathway in animal cells –Waste is lactic acid Alcohol Fermentation  The anaerobic pathway in plant cells –Waste is alcohol

How much energy is produced in anaerobic respiration? For every ONE glucose molecule 2 ATP + 2 ATP = 4 ATP 4 ATP produced per cycle of anaerobic respiration

Which type of cellular respiration is more efficient? Aerobic or anaerobic? Explain your reasoning?

3…2…1… 3 steps of aerobic respiration (include ATP per step) 2 steps of anaerobic respiration (include ATP per step) 1 organelle where cellular respiration takes place