Protein| definition and structure Protein

 Introduction:

Protein is another important macromolecule that makes a bulk of the human body. It has its major role in the growth and development of human body. It is usually the polymer of amino acids. Usually 20 types of amino acids are responsible for protein formation. Out of these 10 are essential that are to be provide in daily diet and 10 are non-essential that our body can make on its own. There are very important for the development and growth of our body as about 50% dry mass of cell is made up of protein. They have great importance from the nutrition point of view. In this article I will discuss about the synthesis of This, transcription and translation. This article will focus only on the synthesis of protein. If you want to know about protein and importance of protein in our body then click on this link and read our article, which will describe about function and sources of protein:

Protein synthesis:

As we know that protein is very important for human being. So it is also important to understand synthesis of protein. Cell in body synthesis protein. RNA with ribosome is involve in this synthesis. There are two basic functions that are involve in protein synthesis. Both are describe below:

1. Transcription
2. Translation

General Overview of Synthesis:

First of all I will give you a general overview about protein synthesis, first step is transcription: In this step DNA creates a copy of messenger RNA (mRNA). This copy gives specific information about the sequence of amino acids. After that it will be the time of transcription. Ribosomes attach on mRNA and t RNA attach amino acids from amino pool on ribosome. After the completion of 20 amino acids with specific sequence polypeptide chain detaches from ribosome.

Protein

As in the previous article we have discussed about transcription. In transcription mRNA strands were formed. Now in this translation ribosomes and RNA attaches amino acids, from amino acid pool in ribosomes according to the coding on mRNA.

Phases of Translation:

1. Initiation
2. Elongation
3. Termination

Initiation:

It is most important phase like transcription. In translation during initial process mRNA attaches with ribosomes.

Elongation:

In this stage ribosomes move along mRNA and read codes and give message to tRNA and t RNA bind amino acids and form a polypeptide chain according to the sequence of cods.

Termination:

It is the last stage for protein synthesis. In this step at the stop codon it is a signal to release ribosome from mRNA and breakup of polypeptide chain from ribosome.

Functions of protein in human body:

Dietary proteins provide amino acids that play their role in the body building and in the maintenance of tissues. Some other important functions of proteins are as follows:

1. Control of acid-base balance:

Proteins and amino acids act as buffers to maintain the acid-base balance of our blood. During normal metabolism, both acids and bases are forme but the amount of acids predominate the bases. Their regulation in our body is done only by proteins and amino acids.

1. Builders of Enzymes, Hormones and Antibodies:

Proteins act as the building blocks of enzymes, hormones and antibodies. All enzymes are globular proteins. As you know that our life will cease without enzymes. So, from this point of view proteins are essential. Hormones are responsible for the regulation of many body processes e.g feed-back mechanism mostly that include the maintenance of body temperature at 37 degree celcius, the regulation of blood sugar level or the process of digrstion etc. All the antibodies that protect us from the antigens or the foreign particles are also protein in nature.

1. Body building:

Although protein is present in each and every cell but have different behavior in various tissues. For example;

• The protein in the muscle allows it to contract and hold fluid. This gives the muscle their strength and integrity to maintain their shape and functioning even when muscles are compose of about 75% water.
• The protein in nails, skin and hair is hard and insoluble, providing a protective covering for the body.
• Proteins in the walls of blood vessels provide elasticity, which is essential for maintaining normal blood pressure and blood flow.
• Proteins provide the framework in which the mineral matter of bones and teeth is embedder.
• Cell organelle formation:

Almost all the organelles of cells are composed of proteins e.g mitochondria, ribosomes, endoplasmic reticulum etc.

• Proteins form the cell membrane that is involved in the cellular transport. So, proteins also have a very selective role and acts as a selector for the incoming and outgoing particles across the cell membrane. In this way, cell membrane acts as a selectively permeable membrane.
• it also form the protoplasm of the cell that is the living and most functional part of the cell.
• Energy provider:

One gram of protein provides approximately 4 kcal (17 kJ) of energy when is oxidize. When total energy intake is inadequate, to meet the need for energy, dietary protein is use. Therefore, in this condition, when the proteins are being use for energy purposes rather than their real function the body protein is starter to be dissolve and the affect person’s body becomes skinny and lean. This mal-usage of protein leads to many diseases such as kwashiorkor, marasmus etc.

Conclusion:

In the light of above discussion we can say that translation is another important and last stage for the production of protein. We can say that it is most important for the production of protein. If you want to know about transcription then click on this link: