Myoglobin Protein

What Are Proteins?
Amino Acids, Peptide Bonds & Levels of Protein Structure 


Organic molecules are large chemical compounds that contain carbon-hydrogen bonds and are found in living things. The major classes of organic molecules are  carbohydrates, proteins, lipids and 
nucleic acids.
Article Summary: Learn about the chemical bonds and different levels of structure that take amino acid monomers to a whole other level, a complex protein polymer.

What Are Proteins? Amino Acids & Peptide Bonds
…all attached to same carbon atom (the α–carbon or alpha carbon). A fourth bond attaches α-carbon to a side group that varies among different amino acids. These side groups are important, as they affect the way a protein’s amino acids interact with one another, and how a protein interacts with other molecules.

Although there are hundreds of different amino acids, most organisms use only 21 to build proteins.

Page last updated: 9/2013
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Endomembrane System of a Eukaryotic Cell, Mariana Ruiz
Continued ... 
Levels of Protein Structure
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​Page last updated: 8/2015
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Amino Acid Monomers
Proteins are polymers (big organic molecules) composed of monomers 
called amino acids.

Each amino acid contains a…
  • base amino group ( -NH2)
  • acidic carboxyl group ( -COOH)
  • hydrogen atom

Amino Acid Chemical Structure
Amino Acid Chemical Structure
Chemical structure of 21 amino acids.
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