Figure 3.3. Phospholipid bilayer forming a biological membrane. Membrane
proteins are here depicted as amorphous, potato-like structures. In actuality,
proteins have a great deal of internal structure.
Here is a representation of two amino acid molecules, with all the
atoms drawn out explicitly:
Hn H WO
IN =G=0, Amino acids N-C-C,
H R, OH H Ro OH
The R groups, R; and Ry, may be the same or different. If amino acid
molecules are simply mixed together in water and shaken up, nothing
happens—they do not spontaneously join together to form chains.
However, in the appropriate environment inside living cells, amino
acids can join together with peptide bonds to form a chain of amino
acids called a polypeptide.
Here is the molecular structure diagram of how two amino acids
can join together into a dipeptide by the formation of a covalent bond