Metabolism and Energy

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Metabolism is defined the sum of all chemical reactions which occurs and are involved in sustaining life of a cell, and thus an organism. Metabolism is of the following two types: catabolism and anabolism. In catabolism, molecules break down producing energy

During anabolism, synthesis of essential compounds needed by the cells are produced (such as DNA, RNA, and protein synthesis).

Bioenergetics describes the metabolic pathways by which a cell obtains energy. Nutrition science studies the relation between food substance and living things. The study deals with:

1) Body requirements of various substances.

2) The function of various substances in body.

3) The amount of the substances needed.

4) The lower levels below which health gets affected.

The food which we eat supplies energy (calories) and supplies essential chemicals which the body cannot synthesize by itself. Food provides substances which are essential for building and repair of body tissues. Food provides substances for efficient functioning of the body.

Energy is trapped in complex chemical compounds and in nutrients. These compounds are broken down to obtain energy. Humans obtain energy from carbohydrates, lipids and proteins. The chemical energy in these molecules is transformed into thermal, kinetic, and other chemical forms.

NUTRIENTS OF HUMAN METABOLISM

Carbohydrates, lipids, and proteins serve as a fuel for the human body. The nutrients are broken down into smaller pieces in the alimentary tract and are absorbed into the blood. This makes it possible for tissues and cells to transform the chemical energy of digestive end products into useful work. The majority of the absorbed products contain monosaccharides, glucose, monoacylglycerol, long chain of fatty...

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...amino acids by cells. All cells do not have proper enzyme machinery and compartments to use all the 3 molecules. Red blood cells are cannot oxidize fatty acids and amino acids as they are devoid of mitochondria. The type of substrate used by the cell changes according to the physiological situation of the cell. Such situations are commanded by different signals. The hormones exert powerful effects which can change the whole cell metabolic profile. Therefore, one should know all the metabolic pathways which control the energy conversion and regulation.

REFERENCES

Blaxter, K. (1989). Energy metabolism in animal and man. Cambridge University Press.

Andrea, T. Da Poian., & Tatiana, El-Batcha. Nutrient Utilization in Humans: Metabolism Pathways. Retrieved from

http://www.nature.com/scitable/topicpage/nutrient-utilization-in-humans-metabolism-pathways-14234029

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