NOW IN NOTES….. 3.2 Summarize the basic aerobic and anaerobic processes of cellular respiration and interpret the chemical equation for cellular respiration.

Cellular Respiration The goal of cell respiration is to convert the chemical energy in nutrients to chemical energy stored in adenosine triphosphate (ATP) The mitochondria break down food to produce ATP in the cellular respiration process. (Powerhouse)

Any food (organic molecules, or nutrient, including carb, fats, and proteins) can be processed and broken down as a source of energy to produce ATP molecules.

Chemical Rxn of Respiration 6O2 + C6H12O6  6H2O + 6CO2 + Energy (36 ATP) Notice it is the opposite rxn of photosynthesis!!!

To transfer the energy stored in glucose to the ATP molecule, a cell must break down glucose slowly and capture the energy in stages. 3 Stages include…….

3 Stages of Cellular Respiration 1. Glycolysis – Anaerobic – No oxygen needed If there is oxygen, continues to the step 2 & 3. If there is no oxygen, fermentation. 2. Citric Acid Cycle – Aerobic – Need Oxygen 3. Electron Transport Chain – Aerobic – Need Oxygen

1st Step: Glycolysis “the splitting of glucose” All respiration processes begin here. 2 molecules of ATP break glucose down into Pyruvic Acid and release 4 molecules of ATP. (Have to put in ATP to get more out.) Takes place in the cytoplasm. If no O  fermentation

Final products of Glycolysis (per one glucose) 2 Pyruvic acids – Krebs Cycle 2 NADH – holds e- until Electron Tran Chain 2 ATP Aerobic Res. produces a much larger amount of ATP than fermentation, up to 20 times more ATP produced

Step 2: Krebs Cycle or Citric Acid Cycle Similar to the Calvin Cycle. The pyruvic acid formed in glycolysis travels to the mitochondria where it is chemically transformed is a series of steps, releasing carbon dioxide and energy.

In Prokaryotes – Krebs occurs in cell membrane. Continue Krebs Cycle In Prokaryotes – Krebs occurs in cell membrane. In Eukaryotes – Krebs occurs in the inner membrane of mitochondria. (matrix, more surface area)

Final Products of 2 turns of the Krebs Cycle from 2 pyruvic acids Final Products of 2 turns of the Krebs Cycle from 2 pyruvic acids So goes around 2 times!! 2 ATP 8 NADH 2 FADH2 6 CO2

Step 3: Electron Transport Chain Most of the energy storing ATP molecules is formed during this part of the cycle. Takes place in the inner membrane of the mitochondria. The etc is a series of chem rxn ending with hydrogen combing with oxygen to form water. For every pair of e- in the ETC = 3 ATP

ETC Final Product 32 ATP Much more than any other cycle or system

Fermentation: Anaerobic Respiration This is the next step, ONLY if no oxygen is present. Fermentation does produce ATP, but only a small amount. (2) Pyruvic Acid  produces Lactic Acid or ethynol. NOT EFFICIENT!!!

2 Types of Fermentation 1. Lactic Acid Fermentation: (muscle pain) Happens in fatigues muscle cells during periods of strenuous exercise. The build up of lactic acid causes a burning pain. Depleted of Oxygen. 2. Alcoholic Fermentation Yeast and some bacteria can break down sugar to produce alchohol, carbon dioxide, and energy Makes bread rise, alcoholic beverages, gasoline, yogurt, cheese.

http://biology.clc.uc.edu/fankhauser/cheese/CHEESE.HTML Dr. Fankhauser has a number of fermentation-related recipes online, complete with photographs: His main cheese page http://biology.clc.uc.edu/fankhauser/cheese/CHEESE.HTML

Why do we need the Oxygen Oxygen serves as the final e- acceptor on the ETC. Oxygen gets rid of low energy e- and H+ ions, the wastes of cellular res.

Final Products of Cellular Respiration (Aerobic) Through Aerobic Respiration a yield of 36 ATP can be produced from 1 glucose. 2 – Glycolysis 2 - Krebs cycle 32 - Electron Transport Chain

Quick energy – lactic acid fermentation – anaerobic Long lasting energy – aerobic cellular respiration 3 steps. When beginning a race, our bodies will use all 3 sources of ATP; ATP already in the muscles, new ATP made by lactic acid fermentation, and ATP made in Cellular Respiration.

35-39% efficient. The rest is lost as heat. Plants need to make ATP as well!! Other compounds come from the Krebs Cycle. Example: amino acids, proteins, ions.

Plants Use Oxygen Too You know that plants give off oxygen. But, there is a problem with knowing that fact. Sometimes knowledge of one thing can interfere with knowing something else. That's what happens in this case. People who know that plants give off oxygen often assume that plants must not also take it in. But this assumption is wrong. All living things--plants included-- take in oxygen from the air. Plant cells have special structures called chloroplasts--named for the chlorophyll they contain. Plants use chlorophyll to capture energy from the sun, then they use that energy to make food in a process called photosynthesis. The food is made by combining small molecules of water with small molecules of carbon dioxide to make larger molecules of starch and sugar. (Oxygen is released as a byproduct of photosynthesis.) The starch and sugar are stored by the plant then used by us when we eat plants. But feeding us is not why a plant goes to all the trouble of making starch and sugar. Plants use the food they make to fuel their own growth and activities. And that's where oxygen comes in again. To "burn" fuel requires oxygen. Animals breathe in oxygen and use it to extract energy from food. This process of using oxygen to release energy from food is called respiration. Plants use oxygen in exactly the same way! But when you have lots of phytoplankton growing in water that's too warm to hold much oxygen, there is little o no oxygen for fish. Algae Bloom.

Homework: Copy & Answer Questions What you need to know for your test! Ultimate goal of Cellular Respiration. Where does respiration take place? What happens in Glycolysis? What is glucose split into? What happens in the Krebs Cycle? Difference between aerobic & anaerobic respiration. Role of Oxygen in Cellular Respiration. Lactic Acid vs. Alcoholic Fermentation. What process of Cellular Respiration makes the most ATP?