1.5 Proteins Flashcards
Proteins
Polymers that have
many subunits (amino acids)
folded into a 3D structure that
determines its function
Most diverse group of molecules in living systems
Proteins
There are thousands of different
proteins within your body
Protein Composition
Proteins are polymers that are made up of amino acid monomers
Amino Acids made up of…
(building blocks of proteins)
A molecule that
consists of a
carboxyl group (COOH), an
amino group (NH2)
and a H atom
How many amino Acids are there
There are 20 different types of R Groups and thus 20 different types of amino acids
Differences in the R Groups gives each amino acid different properties
Amino Acid (R Groups) can be
R Groups may be positive/negative,
polar/non-polar or may
act as acids/bases
Essential Amino Acids
8 Essential Amino Acids
Need to be acquired through diet
Ex. Valine, Leucine, Isoleucine,
Phenylalanine, Tryptophan,
Methionine, Threonine, and
Lysine
Non-Essential Amino Acids
12 Non-Essenital amino acids
Amino acids that can be made in
the body
Proteins are built by…
Attaching Amino Acids into chains
Amino acids are connected by attaching a –NH2
group to a –COOH group by Dehydration Synthesis
The resulting bond is called a…
Peptide Bond
Peptide
a term used to describe a chain of amino acids connected with peptide bonds
Polypeptide
a peptide with more than 50 amino acids
A protein is one or more polypeptides that are folded into
a precise 3D shape
Proteins are only functional after..
folding has occurred
Primary Protein Structure
Linear sequence of amino acids in polypeptide chain
Changing even ONE amino acid in the chain can alter/destroy the final structure/function of the protein
Secondary Protein Structure
The coiling/folding of amino acid chain
Occurs because of hydrogen bonding between different amino acids
Beta-pleated sheet (zig-
zag like pattern) and
Alpha-helix (spiral
pattern) are two
common secondary
structures
Tertiary Protein Structure
Folding of the protein into a
3D shape caused by R-group
interactions
Intermolecular reactions (e.g.,
ionic bonds, hydrogen bonds,
etc.) of the R-groups determine the 3D shape
Tertiary structure is critical to
the function of proteins,
especially enzymes
Quaternary Structure
Linking several separate
polypeptide chains
together
E.g., hemoglobin is made
of 4 polypeptides
Protein Prosthetic Groups
Proteins can also bond with non-protein structures, called prosthetic groups, in order to
function
Many enzymes require prosthetic groups that
contain metal ions to function
