Biology Assignment on Cellular Respiration, Glycolysis, Fermentation

This assignment delves into key biological processes including cellular respiration, glycolysis, and fermentation. It explores the necessity of NADH reoxidation and its role in respiration and fermentation. The assignment also examines the chemiosmotic mechanism of ATP generation and contrasts oxidative phosphorylation with substrate-level phosphorylation. It further analyzes the energy yields of aerobic and anaerobic respiration, and fermentation, explaining the differences in ATP production. Finally, it elucidates the oxidation and reduction processes that occur during glycolysis and respiration, providing a comprehensive understanding of these essential cellular mechanisms. The assignment covers a range of topics from the breakdown of glucose to the production of energy in various cellular processes, providing a detailed overview of the subject matter.

Biological Sciences
1. In a cell, why must NADH be reoxidized? How does this happen in an organism that uses
respiration? Fermentation?
NADH molecule is reoxidized to enable the process of glycolysis of freshly formed glucose.
Reoxidization happens to support the next round of the glycolysis process. Reoxidization of
NADH happens in the organism that uses respiration is based on the type of respiration used
by the particular organism. The organism using aerobic respiration continues the aerobic
citric acid cycle when there is an ample amount of oxygen. In a condition of lack of oxygen,
the organism shifts the process of respiration into anaerobic respiration. Fermentation is said
to be the process of complex substance breaking down into a simple substance.
2. Explain the chemiosmotic mechanism of ATP generation. How does oxidative
phosphorylation compare with substrate-level phosphorylation found in glycolysis and the
Kreb’s cycle?
ATP is created due to the formation of the proton gradient in the membranes of mitochondria.
The mechanism of chemiosmotic is regulated by certain components which are proton pump,
proton gradient and ATP synthase. Oxidative level phosphorylation occurs when ATP is
formed due to the oxidation of NADH and FADH2. It also happens due to the frequent
transportation of the electrons and protons. Substrate level phosphorylation occurs during the
process of phosphorylation when the phosphorylating ADP together with the phosphate and
power offered as the result of the dual reaction. The process of Substrate level
phosphorylation happens outside the mitochondria. This process may take place inside the
mitochondria. During the process, Substrate level phosphorylation which is taking place
outside of cell happens during glycolysis. Substrate level phosphorylation that takes place
inside the mitochondria happens during a citric acid cycle which is also termed as Kerbs
cycle.

3. Which of the following yields the greatest energy for a cell: fermentation, anaerobic
respiration, or aerobic respiration? Which yields the least? Why?
The process that produces more energy is aerobic respiration and it is a rapid process. It
produces 38 ATP/ glucose. The process that produces less energy is stated as fermentation.
This process yields 2ATP/glucose. The comparative analysis confirms that Aerobic cell
respiration generated more energy than anaerobic cell respiration. It is due to the process in
which the anaerobic cell respiration process of glycolysis and fermentation happens. In
Aerobic cell respiration the process covers glycolysis, citric acid cycle and transportation of
respiratory electrons happen.
4. Explain what happens to glucose during glycolysis and respiration in terms of oxidation
and reduction.
Glycolysis is the process of breaking down of glucose products which happen in the cell. It is
considered to be the process of converting sugar into glucose. The process of glycolysis in
respiration is a different phenomenon. During the process of respiration in cells, the glucose
substance breaks down into the molecules of carbon dioxide and water molecules. During this
process, few ATP is formed due to changes that happen in the glucose molecules.
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