Cellular Respiration

Overview of Cellular Respiration the process that releases energy by breaking down glucose and other food molecules in the presence of oxygen This is an aerobic process, meaning that it requires oxygen Referred to as a metabolic pathway Metabolism: a cell’s chemical process It occurs in the Mitochondria

Overall Chemical Equation 6O2 + C6H12O6  6CO2 + 6H2O + energy Or Oxygen + glucose  carbon dioxide + water + energy

Structure of Mitochondria They are found in almost all eukaryotic cells. It consists of two membranes, with a space between the inner and outer membranes. The highly folded inner membrane encloses a thick fluid called the matrix. Many enzymes and proteins are built into the membrane to allow for ATP production. The complex folding pattern allows for many sites where cellular respiration can occur.

There are three process that make up cellular respiration in the presence of Oxygen. Glycolysis Krebs Cycle Electron Transport Chain If it occurred all at once all the energy would be released at once, and most would be lost as heat and light. So it put into steps to release the energy in smaller amounts.

Cellular Respiration – use pg 222 Cytoplasm

Glycolysis – “splitting of sugar” The process in which one molecule of glucose is broken in half, producing two molecules of pyruvic acid, a 3- carbon compound. First step of Cellular Respiration Releases only a small amount of energy. The presence of oxygen determines which pathway is taken to release the energy Occurs in the cytoplasm

1. The Process of Glycolysis Glucose Remember this is the energy of the cell! 2 ATP 2 ADP Electron Carrier 2 Pyruvic Acids 2 NAD+ 4 ADP Uses Oxygen 2 NADH 4 ATP 2 Pyruvic Acids Aerobic Respiration Doesn’t use Oxygen Anaerobic Respiration

Summary of Glycolysis The original glucose molecule has been converted to two molecules of pyruvic acid. Two ATP’s have been spent And Four ATP’s have been produced and two NADPH

2.The Krebs Cycle Also known as the citric acid cycle Occurs in the mitochondrial matrix Pyruvic acid produced from glycolysis is used to make a two carbon compound known as acetyl coenzyme A or acetyl CoA. Acetyl CoA enters the cycle to produvce Carbon dioxide NADH ATP FADH2

Summary of the Krebs Cycle 2 ATP are produced NADH and FADH2 carry electrons to the electron transport chain to make more energy CO2 is released from the cell

3. Electron Transport Chain with ATP Synthase Action The ETC used high energy electrons from the Kreb’s cycle to convert ADP to ATP. Occurs in the inner membrane of the mitochondria and is composed of a series of carrier proteins. Water is produced and released at the end of the ETC. 34 ATP are produced in the end

The Totals Grand Total

Cellular Respiration without Oxygen Fermentation is the process of releasing energy from food by producing ATP without Oxygen (anaerobic). Occurs after Glycolysis Two types Alcoholic fermentation Lactic acid fermentation

Alcoholic Fermentation Yeast and few other microorganisms Produces ethyl alcohol and carbon dioxide gas as wastes. Alcoholic Fermentation

Lactic Acid Fermentation Occurs in humans and other eukaryotes Muscle cramps are caused by a build up of lactic acid When you exercise vigorously, the large muscles run out of oxygen quickly. Your muscles quickly produce ATP using lactic acid fermentation. Lactic acid builds up which causes your muscles to ache.