Fermentation

Glucose

1. Glucose is good for storage but not as good as fuel

   • Glucose must be converted to ATP

ATP

1. ATP stands for Adenosine triphosphate

   • 

2 Ways to Convert Glucose to ATP

1. Fermentation (anaerobic respiration)

   • Does not require oxygen

   • Makes 2 ATP

2. Aerobic Respiration

   • Requires oxygen

   • Makes 36 ATP

We do/prefer aerobic respiration but can also do anaerobic respiration

So, now that glucose has entered the cell…

1. Both types of respiration, aerobic and anaerobic, begin with Glycolysis in the cytoplasm of the cell

   • Glucose is “lysed” (split) in Glycolysis

2. What happens to pyruvate will depend on the presence of oxygen

   

Bacteria

1. How do bacteria benefit from living in our intestines?

   • They get food and a warm environment

2. How do we benefit from having bacteria in our intestines?

   • We get short-chain fatty acids, which we can digest

Mutualism - A win/win relationship

Types of Fermentation

1. Lactic Acid

   • Glycolysis produces 2 lactic acid

   • The purpose is to generate a small amount of ATP without oxygen

2. Alcoholic

   • Glycolysis produces 2 alcohol (ethanol) and 2 carbon dioxide

     

Fermentation Process

1. Recycles NAD+ back to glycolysis

   • ATP can be continually generated even in the absence of oxygen

   • The purpose of Fermentation is to allow glycolysis to continue

2. Only 2 ATP is generated for every glucose molecule

Fermentation product depends on…

1. Type of microorganism

2. Type of fermentation

3. Source of glucose

   

We can measure CO2 to determine the rate of fermentation

Aerobic Respiration

C₆H₁₂O₆ + 6O₂ => 6H₂O + 6CO₂ + 36 ATP

1. Cellular Respiration is a biochemical pathway

   • Series of chemical reactions in which the products of one reaction are consumed in the next

   • Sugar doesn’t combine with oxygen

     

Steps in Aerobic Cellular Respiration

1. Glycolysis (occurs in the cytoplasm) - splits glucose into 2 3-C molecules of pyruvate

   

2. Krebs Cycle (occurs in the mitochondrial matrix)

   

3. Electron Transport Chain (ETC) uses electrons from NADH and FADH₂ molecules to make ATP using the enzyme (ATP synthase)

Krebs Cycle

1. The function of the Krebs cycle is to add electrons to the electron carriers NAD+ and FAD+

   • Pyruvate is used in the Krebs cycle

2. More NADH and FADH₂ => More ETC => More ATP

   • NADH and FADH₂ go to the ETC

   • NADH, FADH₂, ATP, and CO₂ are made in the Krebs cycle

Electron Transport Chain

1. NADH supplies the electrons to the ETC

2. The ETC is a series of proteins that “pass” the electrons down the chain

   

Overview of Cellular Respiration