Protein Assembly

Proteins

Proteins are the most diverse class of biological molecule.  They are composed of long chains of smaller subunits called ‘amino acids’ and proteins can be ‘folded’ into many different structural configurations, resulting in a vast array of possible functions provided to the cell.

Let’s take a closer look now…

Protein Structure

Protein Assembly

Proteins are composed of a series of smaller subunits called ‘amino acids’ which are joined together into a long chain.  If we examine the chemical structure of an amino acid, we can see that it is based upon a central carbon atom bonded to (3) discrete groups along with a hydrogen atom:

Amino Acid

On the left side of the amino acid above, we find an ‘amino group’ which is based upon the nitrogen atom.  It is the presence of this group which provides the ‘amino’ in ‘amino acid’.

Amino Group

On the right side of the amino acid, we find a ‘carboxylic acid group’.  It is the presence of this group which makes an ‘amino acid’ an ‘acid’.

Carboxylic Acid

Amino Groups

Finally, at the top of the amino acid, we find the presence of a ‘variable group’.  There are (20) different groups which can be found in this position on the amino acid generating a total of (20) different amino acids in nature.  Some of these groups can be hydrophobic, some hydrophilic while others can form strong chemical bonds with one another.  The image provides the chemical structure of these 20 different groups.  We won’t worry about the differences between these chemical structures, but you should be aware that this chemical diversity provides the basis for the variety of functions carried out by proteins inside the cell.

Protein Assembly- video

Proteins are composed of a series of smaller subunits called ‘amino acids’ which are joined together into a long chain.  The video below explores how proteins are assembled from amino acids.

Summary

Proteins are composed of a series of smaller subunits called ‘amino acids’ which are joined together into a long chain.  If we examine the chemical structure of an amino acid, we can see that it is based upon a central carbon atom bonded to (3) discrete groups along with a hydrogen atom:

Amino Acid

  1. On the left side of the amino acid above, we find an ‘amino group’ which is based upon the nitrogen atom.
  2. On the right side of the amino acid, we find a ‘carboxylic acid group’.
  3. At the top of the amino acid, we find the presence of a ‘variable group’.  There are (20) different groups which can be found in this position on the amino acid generating a total of (20) different amino acids in nature.  Some of these groups can be hydrophobic, some hydrophilic while others can form strong chemical bonds with one another.

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BIO109 Biology I Introduction to Biology Copyright © by Diane Rinehart. All Rights Reserved.

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