Cellular Respiration

Respiration The breakdown of simple food molecules such as glucose and the release of the energy it contains Respiration does not refer to a person breathing

Aerobic and Anaerobic Respiration Aerobic- Occurs in the presence of oxygen Anaerobic- Does not occur in the presence of oxygen. Does not yield as much energy

Aerobic: Glucose + oxygen yields carbon dioxide + water

Energy is produced in the form of ATP(Adenosine Triphosphate) ATP is a high energy molecule that the body uses as its source of energy Respiration is the process that produces ATP

Aerobic Respiration

Aerobic Respiration Begins with glycolysis (cytoplasm – 2 ATP) Pyruvic acid (3-carbon compound) moves into mitochondria Krebs cycle (2 ATP produced) Electron transport chain (32 ATP produced)

Glycolysis First Stage of respiration Glucose is broken down in the cytoplasm The mitochondria can only breakdown smaller molecules to yield energy Pyruvate 3- carbon sugars Occurs in both aerobic and Anaerobic respiration Produces a net yield of 2 ATP How many carbons does glucose have?

Glycolysis

Second Step of Cellular Respiration Krebs Cycle Small molecules (pyruvate) broken down further The chemical reactions require oxygen Minimal amount of energy is released Known as the krebs cycle Occurs in the mitochondrial matrix Produces electron carriers Positively charged molecules Produces 2 ATP

Electron Transport Chain Movement of electron carriers (NADH and FADH2) across the cell membrane A hydrogen ion gradient is produced by actively transporting hydrogen ions out side of the mitochondria As the hydrogen ions diffuse back into the cell through the enzyme atp synthase ADP and a phosphate ion are bound producing ATP. Yields 34 ATP

Anaerobic Respiration

Anaerobic (alcohol fermentation): Glucose→ ethanol alcohol + carbon dioxide

Anaerobic (lactate formation): Glucose → lactic acid

Fermentation Occurs during anaerobic only No additional ATP are made End products vary Yeast: ethyl alcohol and carbon dioxide Yeast is used to make bread rise (because CO2 is produced) and to make alcohol products Bacteria: lactic acid

Muscle Fatigue Caused when not enough oxygen is reaching the muscles Lactic Acid builds up and is not broken down fast enough The more mitochondria there are in an area the less fatigued the muscles get

Recap Aerobic: Glycolysis & Kreb’s cycle/electron transport chain Anaerobic: Glycolysis & Lactate Formation or Alcohol Fermntation  

Respiration of Fats and Proteins Cells can utilize other organic compounds in aerobic respiration Compounds produced enter at a different point in the pathway

http://www. teachersdomain. org/resource/tdc02. sci. l ife. cell http://www.teachersdomain.org/resource/tdc02.sci.l ife.cell.mitochondria/