Question

1. Explain the process by which excess nutrients are converted to energy storage molecules and compare and contrast glycogen and fat as energy storage molecules.

2. Explain the role of ATP in living things. List the major inputs and outputs of aerobic respiration. Describe how the inputs are delivered to cells and the waste products removed. Describe the three major stages of aerobic respiration.

Answer 1

1. The energy for the living organisms are obtainable from ATP, which is known to be produced by the metabolic reactions of carbohydrates, proteins, and fats in the cytoplasm and mitochondrion of the cell through the ATP production pathways, including glycolysis and citric acid cycle. If the amount of ATP available is in excess of the body’s requirements, the liver would store energy in the form of glycogen in the liver and skeletal muscle cells through the usage of excess ATP and glucose. When blood sugar drops, the release of glucose from stores of glycogen by the liver would occur.

2. The role of ATP in living things-

ATP is known to be present in all cells of the living organisms and useful for transporting energy for cellular metabolic activities, including muscle contraction and maintaining of body temperature.

List of Major inputs and outputs of aerobic respiration

Process	Input	Output
Glycolysis	glucose, ADP, and NAD+	2 pyruvate, 2 ATP, and 2 NADH
Transition step	2 pyruvic acid, 2 CoA, 2 NAD+	2 CO2, 2 ACoA, 2 NADH
Krebs cycle	2 ACoA, ADP, 6 NAD+, 2 FAD	4 CO2, 2 ATP, 6 NADH, 2 FADH2
Oxidative phosphorylation	10 NADH, 2 FADH2, 6 O2, ADP	10 NAD+, 2 FAD, 6 H2O, 34 ATP

Describe how the inputs are delivered to cells and the waste products removed

The input of glucose originated from the foods is delivered to cells through the blood stream. The carbondioxide and water are the two main waste products that are generated in mitochondrial part of the cell during the breaking of chemical bonds in glucose. The water generated through the mentioned process would be utilized by cytoplasm of the cell, however the carbon dioxide will absorb into the blood stream and expel from the body through the lungs.

Three main stages of aerobic respiration

During the aerobic respiration, the energy from glucose is released in the presence of oxygen. There are three main stages of aerobic respiration, including glycolysis, Krebs Cycle and Electron Transport Chain

Glycolysis- During this process, the glucose is broken down into 3 carbon molecules during the oxidation process takes place in cystol of the cell. As a result of this, the 2 ATP molecules and 2 NADH molecules that carries 2 energy electrons are produced.

Krebs Cycle: During this cycle, the release of carbon Dioxide from the 3-carbon molecule and oxidation of the two carbon molecule will produce 6 CO2 molecules, 8 NADH molecules, 2 FADH2, and 2 ATP.

Electron Transport Chain- In this stage, the unreleased energy during both the Glycolysis and Krebs Cycle are released. The water is produced from the addition of electrons released from NADH and FADH2 and protons to the oxygen. Also, the ATP would be reduced during the movement of the protons across the cell membrane. The high amount of ATP would be produced during this process compared to Glycolysis and Krebs Cycle.