Unit 4_425

Structure and metabolism of carbohydrates, fats and proteins

Carbohydrates, fats and proteins are the major food components that the body needs most. They have different purposes that they serve in the human body. A balanced diet therefore is supposed to have these food components. They are also required in different components in the human body (Sacks et al, 2009). Proteins, carbohydrates and fats have different and are metabolized differently

The structure of the food components refer to the arrangement of the compounds that make up the substance. To start with, carbohydrates are made up of carbon, hydrogen and oxygen. 6 atoms of carbon combine with 12 atoms of hydrogen and 6 atoms of oxygen to make a carbohydrate molecule (Sacks et al, 2009. Generally, the most complex form of carbohydrate is starch. Therefore, the foods that are rich in starch are the greatest sources of carbohydrates in the human body. These include all cereals e.g. maize, wheat and sorghum. Cassava is also rich in starch.

The basic form of carbohydrates is called monosaccharide (exemplified by glucose, fructose and galactose) When more than one monosaccharide combine, they form disaccharides (which include maltose, lactose and sucrose) More than one disaccharides combine to make a polysaccharide (which is best exemplified by starch and chitin) therefore, in a starch molecule, there are large chains of disaccharides that are in turn formed by chains of monosaccharide (Sacks et al, 2009

Structural formula of a carbohydrate

C6H1206

Fats

Like carbohydrates, fats are made up of carbon, hydrogen and oxygen. The difference in the structure of fats and that if carbohydrates is that, while carbohydrates molecules are made up of 6 oxygen atoms, fats are made up of 5 oxygen atoms per molecule. Therefore, the basic difference between the structure of a carbohydrate and that of a fat is that, carbohydrates are made up of more oxygen atoms in the structure than fats. Below is the structural formula of a fat molecule

C6H1205

Generally, the structure of a fat molecule is made up of fatty acids and glycerol three fatty acid molecules combine with one glycerol to make a triglyceride which is the fat molecule. Below is a structural representation of a lipid

Fatty acid

+ =

Fatty acid

Fatty acid

Glycerol

Glycerol

Fatty acid

Fatty acid

Fatty acid

3 fatty acids + 1 glycerol = triglyceride (fat molecule)

Proteins

Generally, proteins are made up of carbon, hydrogen, oxygen and Nitrogen. However, they have elements of phosphorous and sulphur attached. The basic structure of a protein molecule is made up of amino acids. Amino acids are the most basic building blocks of proteins. There are twenty amino acids that make up proteins. Of the twenty, 9 are not made by the body and therefore must be taken with food. These are called the essential amino acids. The other 11 are synthesized and are called non essential amino acids.

Deeper in to the structure of a protein, an amino acid molecule is made up of amino groups that are basic and carboxyl groups that are acidic. Therefore, a protein molecule is made up of many amino acid chains made up by combination of amino groups and carboxyl groups.

Below is a structural representation of an amino acid molecule

[NH2 COOH] n

Metabolism

Metabolism is the process of breaking down food molecules into energy. In metabolism, the basic forms of the food molecules are broken down in the presence of oxygen to release energy (Cahn & Houget, 2013). A glucose molecule gives up to 38 ATP molecules. A gram of lipids on the other hand produces nine calories. They are metabolized when the carbohydrates are over. A gram of proteins on the other hand supplies four calories but are last in the pecking order (Jackson, Morrisett, & Gotto, 2006).

Individualized sports nutrition plan for James (an athlete)

Athlete: James Remy

Age: 32

Current weight: 115

Ethnicity: Latin American

Sport: Football

Training schedule: James spends 6 hours in the pitch doing exercise every day from Monday to Friday. On Saturday, the hours of exercise increase to eight. Sundays are free days for the sportsman. However, his schedules are affected by the game schedules and must as a team compensate for lost exercise time. This is according to his current club exercise policy.

Diet: James eats two scrambles eggs every morning served with a glass of milk. At 10 AM, James takes 2 apples, and orange juice served with slices of bread and peanut butter. At lunch hour, James eats fries served with ¼ chicken from a team hotel and drinks 2 glasses of water. At 4 PM, James takes green salad. At 7 PM, he takes a plate of rice served with green vegetables. At 10PM, James takes 2 glasses of wine and goes to bed.

The information on the activity of the daily activity James is important in determining the required daily dietary uptake. The table below shows that recommended level of uptake for James obtained using the nutrition analysis calculator as well as the level that James is taking calculated using similar program.

Table summarizing his daily intake

According to the uptake table, the uptake of the sportsman is almost at par with the recommended level of uptake for a man of his daily activity. He should therefore continue with this uptake.

References

Cahn, T., & Houget, J. (2013). The metabolism of carbohydrates, fats and proteins during hyperthermia. Compt. Rend. Soc. Biol.(Paris (113: 587, 1933. CAS.

Jackson, R. L., Morrisett, J. D., & Gotto, A. M. (2006). Lipoprotein structure and metabolism. Physiological reviews, 56(2), 259-316.

Sacks, F. M., Bray, G. A., Carey, V. J., Smith, S. R., Ryan, D. H., Anton, S. D., ... & Leboff, M. S. (2009). Composition of fat, protein, and carbohydrates. New England Journal of Medicine, 360(9), 859-873.