CELLULAR RESPIRATION

Mitochondria Organelle where cellular respiration takes place Most of the cell’s ATP is made here

Cellular Respiration Process by which glucose is broken down to produce energy (ATP) The cellular respiration reaction is: energy C6H12O6 + 6O2 6H2O + 6CO2 There are two types of cellular respiration: Aerobic Anaerobic

Aerobic Respiration There are 3 steps in aerobic respiration: Glycolysis Krebs cycle Electron transport

Glycolysis Glucose is broken down to produce 2 molecules each of pyruvic acid (a.k.a. pyruvate) and the energy carriers ATP and NADH These reactions occur in the cytoplasm

Krebs Cycle The pyruvic acid made during glycolysis is converted into acetyl CoA before it can enter the Krebs Cycle The acetyl CoA enters the Krebs cycle and is converted into CO2 (a waste product), ATP, NADH, and FADH2 The NADH and FADH2 can now enter the electron transport chain These reactions take place in the mitochondria

Electron Transport Chain NADH and FADH2 are put through the chain so that their energy can be used to convert ADP into ATP These reactions require oxygen, which accepts the H+ ions to form water Occurs in the mitochondria

ATP is made during all 3 parts of aerobic respiration The entire process of aerobic respiration produces 36 ATP molecules

Anaerobic Respiration The extraction of energy from food for ATP production in the absence of oxygen This is also known as fermentation The process begins with glycolysis to produce pyruvic acid There are 2 types: Alcoholic fermentation Lactic acid fermentation

Alcoholic Fermentation pyruvic acid + NADH CO2 + ethanol + NAD+ This reaction occurs mainly in yeast cells Used to make bread as well as alcoholic beverages

Lactic Acid Fermentation pyruvic acid + NADH lactic acid + NAD+ This reaction occurs in muscle cells and it is the build up of lactic acid that causes pain in the muscle during strenuous exercise

Excess Glucose If the glucose that is taken in through food is not used, it will be stored Animal cells store it as glycogen or fat

Comparing Photosynthesis and Cellular Respiration Photosynthesis and Cellular Respiration are opposing processes; their chemical equations are said to be opposites energy (from the sun) 6H2O + 6CO2 C6H12O6 + 6O2 energy (ATP) C6H12O6 + 6O2 6H2O + 6CO2 Cellular respiration occurs in all eukaryotic cells, but photosynthesis only takes place in plants, algae, and some bacteria