Question

5. What critical role does NAD+ and FAD play in cellular respiration? 6. List the major reactions of cellular respiration. Where does each reaction occur inside the cell? 7. What two types of reactions are anaerobic? What is the difference between glycolysis and fermentation? 8. What are the advantages and disadvantages of fermentation? What is the difference between bacterial fermentation and yeast fermentation?

Answer 1

Cellular Respiration

C6H12O6 + 6O2 ---------------------> 6CO2 + 6H2O + ~38 ATP

The process of breakdown of sugar in presence of oxygen is known as cellular respiration. Partial process of which occurs in the cytoplasm, and other part in the mitochondria.

Cellular Respiration can be broken down in to 4 steps:

1- Glycolysis- In this process 1 Glucose (C6H12O6) molecule is broken down to 2 molecules of pyruvic acid. This process occurs in the cytoplasm of the cell

2- Krebs Cycle- It is the process which occurs in mitochondrial matrix where two molecules of pyruvate is converted in to acetyl CoA

3- The Electron Transport Chain- It is the process which occurs at the cristae of the mitochondria

Role of NAD+ and FAD

Nicotinamide Adenine Dinucleotide when is found in oxidised state it is known as NAD+ It picks up an electron from Glucose and becomes NADH. Then NADH, along with flavin adenine dinucleotide (FADH2) transports the electrons to the mitochondria, where the cell takes up the energy stored in the electrons.

Anaerobic Reactions

These reactions take place when there is very little amount of oxygen is present to support the aerobic reaction. The two types of aerobic reactions present are- alcoholic fermentation and lactic acid fermentation.

Alcoholic fermentation is the process in which glucose is converted in to ethanol. This process is practiced by microorganisms like yeast and bacteria.

Lactic acid fermentation is the process is found in animals when there is very less amount of oxygen present to perform aerobic reaction like at the time of exercise.

Difference between glycolysis and fermentation:

Glycolysis is an aerobic reaction whereas fermentation is an anaerobic reaction

Glycolysis produces two pyruvic acid molecules whereas fermentation produces two ethanol molecules

Glycolysis produces two molecules of ATP whereas fermentation has a by-product called carbon di oxide

Advantages of fermentation

Lactic acid can be produced and it can produce energy for ATPs. Fermentation is used for preservation in a process that produces lactic acid as found in such sour foods as pickled cucumbers, kimchi and yogurt.

Disadvantages of fermentation

Production can be slow, the product is impure and needs to have further treatment and the production carries a high cost and more energy.

Difference between yeast fermentation and bacterial fermentation

Yeast fermentation is the process of producing ethanol and carbon di oxide which is used in food processing like bread, beer and wine

Bacterial Fermentation is the enzymatic decomposition of carbohydrates which is used like a food by bacteria. Fermentation bacteria are anaerobic