CP Biology
2015-16
Name
______
____________
Biochemistry Part II
PROTEINS
Of all the organic compounds, proteins are the largest,
most complex, and most diverse.
While 70% of the body is water, most of the other 30% is
protein!
_________________
_.
• Made of elements C, H, O, N
• Made of AMINO ACIDS (the monomer)
• PEPTIDE bonds link amino acids together to make
polypeptides
Many linked amino
acids is a
______________
• One or more polypeptides “fold” into a PROTEIN
Proteins are Diverse
• Twenty (20) amino acids exist in nature
• Different combos of amino acids lead to different
functioning proteins
• The sequence of DNA directs the sequence of amino
acids.
Personal notes, summary of lesson, questions:
One or more
polypeptides folds
into a
______________
1
AMINO ACIDS
Amino acids are compounds with an AMINO group
(-NH2) on one end and a CARBOXYL (-COOH) group on
EXAMPLES OF SOME SPECIFIC AMINO ACIDS
Circle each amino group, box each carboxyl group and
label each R group (-R).
the other end.
Each amino acid consists of one of each of the following,
connected to each other by covalent bonds.
1) central carbon atom (-C-)
2) carboxyl group (-COOH)
3) amino group (-NH2)
4) one hydrogen atom (-H)
5) 'R' (variable) group - one of 20
different side chains
On the two amino acids below, circle the atoms that must
be removed in order to create a peptide bond.
Because of their uniform structure, any amino acid can bond These atoms create a _______________ molecule, which is
a product of the reaction.
to any other amino acid using a covalent bond called a
peptide bond.
THINK ABOUT IT: What process will link together two
individual amino acids? _______________________
Glycine
Personal notes, summary of lesson, questions:
Valine
2
POLYPEPTIDES
Segments of amino acids are called polypeptides
When they are first assembled, polypeptides are
LINEAR (straight) chains.
They are not yet functioning proteins!
R groups on the amino acids interact with each other
causing the polypeptide to fold into a specific 3dimentional shape or structure.
Once it is completely and correctly folded, it is
considered a protein. (other small changes or
modifications may also occur before the protein is
completely functional)
-How many amino acids are shown in the polypeptide
below? _______________ (Hint: count the R groups)
-How many peptide bonds are shown in the polypeptide
below? ______________ (Hint: peptide bonds are between
which two atoms?)
The structure of each protein in unique; STRUCTURE
(or FORM) leads to FUNCTION!
-How many water molecules were released as this
polypeptide was formed?______________ (Hint: one for
each bond made!)
Personal notes, summary of lesson, questions:
3