Chemistry of Life Relating Molecular Structure to Biological Function - Coursework Example

• Types of proteins

The type and classification of protein is dependent majorly on its basic component. The basic component of protein is the amino acids. Nutritionally, there are two types of amino acids. That is the essential amino acids and the non-essential amino acids (Wirtz and Packer, 2013). The essential amino acids are those that the body cannot manufacture and are not easily obtainable hence there need on the diet. The essential amino acids that the body need most includes tryptophan, phenylalanine, Histidin, methionine, threonine, lysine, valine, isoleucine and arginine (Hiraku & Masahiro, 2015). The absence of this proteins can be fetal for the human body. It can result in a number of pathologies in the system.

The other type of amino acids is known as the non-essential amino acids. This are the amino acids that are not needed because they are easily obtainable. The non-essential amino acids include the following: alanine, glycine serine, tyrosine, praline, hydroxyl praline, cysteine, cystin, glutamic acid & aspartic acid (Yi and Zhang, 2016). The types of the amino acids can also be based on metabolic activities. On this method of classification, the amino acids are classified as either ketogenic amino acids which include leucine, glycogenic amino acids or as both ketogenic and glycogenic amino acids. The metabolic breakdown of the ketogenic amino acids results in creation of the ketone bodies while glycogenic amino acids will yield to glucose (Han & Tian, 2013). More so, classification can be based on the charge of the amino acid. There those that are hydrophilic such as threonine and the other are hydrophobic alanine

• Structures

Protein is a complex substance that is composed with several amino acids that are joined by peptide bonds. There are three structures of the proteins. The primary, secondary, tertiary and the quaternary structure.

Primary structure of Protein

It is the simplest structure of the proteins. The amino acids are held together by the peptide bonds (-CO-HN-). The primary structure of the protein is as illustrated in Figure 1. Any change of the sequence on the amino acids of the polypeptide chain will results in the physiological defects.

Figure 1: Han & Tian, 2013

Secondary Structure of Proteins

The secondary structure is characterized by the formation of the folds. It is the combination of two primary proteins that end up forming a polypeptide fold that may conform with a number of structures. The following are the dimension of the structure that may end up being formed.

• Alpha-Helix

It is the commonest structure of the secondary proteins and of globular type. This protein has H-bonding that makes them to be helical in nature. The H-bonding is between the amine nitrogen and the carbonyl groups of the peptide bonds. The diagram on Figure 2 is an example of the secondary structure of protein known as Alpha-Helix.

Figure 2: Han & Tian, 2013

• β-pleated Sheets Proteins

The β-sheets are identified by two or more dissimilar regions of stretches of between five to ten amino acids. It is a type of secondary structure of the proteins. The structure is as result of the folding of proteins on the backbone of the polypeptide (Rustad and Sailer, 2016). It is strengthened by H-bonding between the amide nitrogen and the carbonyl components. Figure 3 shows the diagram of β-pleated Sheets Proteins.

Figure 3: Han & Tian, 2013

Tertiary Structure of the Proteins

It is identified by a complete three-dimensional structure of the protein. It is a combination of more secondary structure. Secondary structure of protein forms domains which later forms the basis of forming the tertiary structure of the proteins whose smallest units are known as polypeptides (Damaraland, 2016). The coming together of the domains is controlled with a number of bonding forces which includes the van der Waals, Hydrogen bonding, hydrophobic forces, disulphide forces and the electrostatic forces. Figure 4 shows a diagram of tertiary structure of the protein.

Figure 4. Sources Han & Tian, 2013

Quaternary Structure

The quaternary structure is formed when a monomer to monomer interaction occurs to form an oligomeric protein. An oligomeric protein is the one that is formed when more than two polyptide chains. The following diagram on Figure 5 shows a quaternary structure.

Figure 5: Source Han & Tian, 2013

• Function

Function of Carbohydrates

The function of carbohydrate in the body is reduced to its simplest form which is glucose. Glucose is needed for the metabolism of the cells in the body to provide the energy. Half of the energy in the body is provided by the glucose while the other is provided by glycogen that is stored in the body. Glucose is also used as thermoregulatory. When there is cold, the rate of metabolism increases leading to the production of heat for the body to maintain its functions. The functionality of brain is dependent on glucose as source of energy (Gropper & Groff, 2009). It is this energy that is used in the transmission of the neural impulses for a given action to be taken. Without the glucose, the neural function will stall. The cerebral blood flow also needs energy for it to occur. Muscles need to be contracting and relaxing for them to develop. The cells in the muscles needs the glucose for their activity. In a day, muscle cells need close to 100-150 microgram of glucose without which the atrophy of muscle will ensue. The function of the glucose in the body therefore cannot be underscored since it is vital for the day to day activity. The excess of glucose is converted into glycogen and fat adipose tissue. This stored glucose is latter used during starvation.

Function of Lipids

The lipids are obtained in diet through oil and fats. Nutritionally, oil make the foods that human beings eat to be palatable and bring sense of satiety. Omega-3 oil that is obtained from fish is good for the health of the heart since they are low in cholesterol. The fat adipose tissues are used during the starvation by being broken down by body (Kamp, 2014). The lipids are also important in the membranous body part. The phosphor lipids are the main component of the cell membrane. More so, lipids are most important in the transportation of the vitamins in the body. Cholesterol which is lipid found in the cell membrane is a combination of a steroid and alcohol which is used the synthesis of hormones such as sex hormones, cortisone and vitamin D.

Function of Proteins

Proteins have several function in the body especially from the biochemistry point of view. The following are the function of proteins. First and foremost is enzymatic. It acts as catalyst in the metabolic activity (Rustad and Sailer, 2016). The liver function depends on protein for them to take place. The gastric digestion also depends on protein component known as enzymes for them to digest food component.

The second function of the protein is hormonal where the protein based chemicals are produced to mediate message between cell to cell. An example is insulin which is a metalloproteinase that transport glucose from the blood stream to the cells. The other function of protein is structural where the component such as nails, connective tissues and other body structure depends on the protein for the strength. Such proteins are known as fibrous and they include collagen and keratin that stabilizes structures in the body.

Protein is also used as reservoir or a storage component. Iron which is used in the body for the formation of the red blood cells, is stored in the body by a protein known as ferratin. Without the protein, the excess effect of iron in the body will be felt (Kamp, 2014). It may cause serious manifestation that may result to death. More so, protein is used as contractile components. The contractility of heart and muscles is dependent on proteins. Besides, protein is used a transporting agent in the body such as hemoglobin that transport oxygen and a lastly, protein is used as receptor on the surface of the cells to regulate the substance that enter the cell in the human body.

D. The Treatment

Glucose disorder

One of the glucose disorder is glucose storage disorder (GSD) where the liver cannot regulate the amount of glucose that is converted to glycogen or its breakdown when there is starvation. Consequently, there is excessive storage of the glycogen in the liver while at the same time there is inadequate glucose that is released to the blood stream for the cells to use. It is due to lack of a regulating hormone that balances the storage and breakdown of the glycogen. The historical management of the GSD was done by consumption of corn starch helps in keeping the blood sugar low hence no conversion to glycogen. The patients are also fed with carbohydrate in a continuous mode during the day. In the modern time, GSD is managed by recombinant DNA alglucosidase alfa also known as Myozyme that is used in breaking down the lysosomal glycogen.

Lipid disorder

One of the lipid disorder is Gauchers diseases which is a lipid metabolism disorder. It is a rare disease that is caused by absence of glucocerebrosidase. Due to absence of this enzyme, there is accumulation of fatty substance in the body parts such as bone, spleen, lungs, brain and liver. Historically, Gauchers disease has had no cure but in the modern times of the medical advancement there is enzyme replacement that allows management of the lipids from the accumulating on the organs (Consumer Medication Information, 2016).