• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

Proteins are extremely important and are around 50% of the dry mass of most cells in the body.

Extracts from this document...

Introduction

Proteins Proteins are extremely important and are around 50% of the dry mass of most cells in the body. The main uses of proteins are: * Essential component of a cell membranes. * Haemoglobin used to transport oxygen is made up of protein * Antibodies are made of proteins * Most enzymes are made of proteins * Hair and surface layers of the skin contain proteins (keratin) * Collagen another protein used to strengthen bones and artery walls. When proteins are broken down they form amino acids, these then produce many different chemicals. There is a set structure for these chemicals. It revolves around carbon, one side has an amine group (-NH2) and on the other a carboxylic acid group (-COOH) ...read more.

Middle

This reaction can also be reversed which is called hydrolysis (gain of water), this reaction is usually done in the stomach and small intestine but at ribosome as well. There are three different ways of representing the structure of proteins: * Primary structure * Secondary structure * Tertiary Structure * Quaternary structure The primary structure shows the basic form of the polypeptide. It shows the amino acids involved and in which sequence they are joined. This form is mainly used to work out the chemistry of the protein since it shows all of the chemicals used. The secondary structure shows the effect the amino acids have on each other. The structures given are simplified down to, in a chain of polypeptide the -CO group is attracted to the -NH group ahead of it and so move towards each other, forming an ?-helix. ...read more.

Conclusion

R groups, Disulphide bonds form between cysteine molecules, Ionic bonds form between R groups containing amine and carboxyl groups, Hydrophilic bonds interactions occur between R groups which are non-polar or hydrophobic. Quaternary Structure is the association of different polypeptides chains in protein. How different proteins are joined together. Globular and fibrous proteins have a special structure where the molecules curl up into a "ball" e.g. myoglobin, haemoglobin. The reason for the molecule folding is to place the hydrophobic ends in the center and the hydrophilic ends pointing outwards. This will allow it to dissolve. Globular proteins have a lot of roles in metabolic reactions, enzymes being globular proteins. The opposite of globular proteins are long strands known as fibrous proteins. These have more structural roles such as keratin in hair and collagen in skin. Nitesh Patel LVI PK ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our AS and A Level Molecules & Cells section.

Found what you're looking for?

  • Start learning 29% faster today
  • 150,000+ documents available
  • Just £6.99 a month

Not the one? Search for your essay title...
  • Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month
  • Over 160,000 pieces
    of student written work
  • Annotated by
    experienced teachers
  • Ideas and feedback to
    improve your own work