5. Cellular Respiration

A. Basic Process 1)In respiration, energy from food is converted to chemical bond energy to be used by cells 2)The only usable source of energy for a cell is ATP

3. Structure of ATP

4. The ATP Reaction: ATP + H2O ADP + P + Energy

5.) 2 Types of respiration ANAEROBIC RESPIRATION--does not use O2, makes very few ATP’s AEROBIC RESPIRATION--uses O2; most organisms carry out aerobic respiration, Makes lots of ATP

B.) Gas Exchange 1.) Oxygen must be absorbed from the environment in aerobic respiration 2.) Carbon Dioxide must be released 3.) Complex organisms have a respiratory system

c.) Chemical Respiration 1.) Must occur all the time in ALL organisms 2.) Respiration is a characteristic of life 3.) Aerobic respiration occurs in the mitochondria of the cell 4.) Anaerobic respiration occurs in the cytoplasm

D.) Anaerobic Respiration 1.) Occurence Some simple organisms only carry out anaerobic respiration Also known as fermentation In muscle cells, lactic acid is formed in anaerobic respiration. This causes muscle fatigue.

2.) End Products of anaerobic respiration; Either lactic acid or alcohol and carbon dioxide

3.) Energy release Anaerobic respiration produces 2 ATP per molecule of glucose Most of the energy is in the lactic acid or alcohol The anaerobic process is known as Glycolysis

E.) Aerobic Respiration 1.) General Process Molecules of food are broken down into carbon dioxide and water Produces 36 molecules of ATP per glucose

2.) Oxidation-Reduction Reactions: In aerobic respiration, glucose is oxidized to release energy. The energy is used to make ATP 3.) The Role of Oxygen: Oxygen accepts hydrogen atoms released in oxidation forming water 4.) Overall equation for Respiration:

F.) Phases of Respiration 1.) Anaerobic Phase: Glucose + 2 ATP  2 Pyruvic acid + 4 ATP What is the net gain of ATP in this phase? _____

2. Aerobic Respiration: Pyruvic acid enters the mitochondria In the mitochondria, Pyruvic acid is further broken down to give 34 ATP’s Net gain of ATP is 36 from the complete oxidation of 1 glucose molecule

Respiration Summary Anaerobic Respiration Produces CO 2 and either ethyl alcohol or lactic acid Makes a net gain of 2 ATP/glucose Aerobic Respiration Produces CO 2 and water Makes a net gain of 36 ATP/glucose