Cellular Respiration  Respiration

• Respiration – the biochemical process that makes ATP from glucose • Occurs in both AND autotrophs and heterotrophs.  Respiration

• There are two types of respiration, AEROBIC and ANAEROBIC. • Aerobic respiration requires OXYGEN to release energy.

• The chemical equation for aerobic respiration is:

C6H1206 + 6O2  6H2O + 6CO2 + 36 ATP Glucose Oxygen Water Carbon Dioxide Energy  Respiration

• Anaerobic respiration DOES NOT REQUIRE OXYGEN. (Also called FERMENTATION)

• Both aerobic and anaerobic respiration begin with the same process, glycolysis.  Glycolysis

• Occurs in CYTOPLASM • Means “split the sugar,”

• The chemical equation for glycolysis is:

C6H12O6 + 2 ATP  2 Pyruvic acid + 4 ATP

 Glycolysis

1. Glucose molecules are broken down into 2 pyruvic acid (pyruvate) molecules 2. Two ATP molecules are used and four ATP molecules are created resulting in a net gain of two ATP. 3. Following glycolysis, the pyruvic acid molecules can follow two paths: aerobic respiration or anaerobic respiration.  Glycolysis

2

Glucose

Glycolysis  Aerobic Respiration

• Occurs in the MITOCHONDRIA 1. Pyruvic acid molecules are converted to Acetyl-CoA molecules.

2. Acetyl-CoA broken down into H+, CO2, and ATP • Krebs Cycle 3. The H+ ions bond to carrier molecules, NAD+ and FAD to make NADH and FADH2.  Aerobic Respiration

4. NADH and FADH2 go through a series of step reactions – the electron transport chain – to produce ATP.  Aerobic Respiration

• Each cycle produces 10 NADH

molecules, 2 FADH2 molecules and 2 ATP. 1 NADH = 3 ATP

1 FADH2 = 2 ATP

• The end product of aerobic respiration is the production of 36 ATP MOLECULES.

 Aerobic Respiration

Glucose 2 36

Glucose Glycolysis

Glycolysis Krebs Electron cycle transport  Anaerobic Respiration

• Occurs in the CYTOPLASM.

• Occurs in the absence of oxygen  Anaerobic Respiration

• Lactic acid Fermentation- converts pyruvic acid to lactic acid and CO2 – Lactic acid can build up in muscles when they run out of oxygen and causes muscle soreness

• Alcoholic fermentation- converts pyruvic acid to ethanol and CO2 – Process used to make wine, beer, cheese, and bread

• Both processes result in the production of only 2 ATP MOLECULES.

 Factors Affecting Respiration:

• ATP concentration - the more ATP molecules available, the slower the rate of respiration.

 Anaerobic Respiration

2 36

Glucose

Glycolysis Krebs Electron cycle transport

Fermentation Alcohol or (without oxygen) lactic acid