SBI4U0
BIOCHEMISTRY: PROTEINS
Name:
Date:
FUNCTION
1) ___________ and control chemical reactions
2) hormones and chemical messengers
3) structure and support
4) ____________ speed up reactions
 About _______% of the human body’s dry weight is protein.
STRUCTURE

polymers of amino acids – there are ______ different amino acids

amino acids are made from a combination of carbon, hydrogen, oxygen AND ________________

all amino acids have the following:

o
____________ group (NH2)
o
____________ group (COOH)
o
side chain or ______ group
the function of the amino acid is determined by the properties of the ___ group such as:
o
structure, shape and space occupied
o
charge
o
ability to form bonds

proteins are formed by dehydration synthesis reactions (removal of a ____________ molecule)

the bond that forms between two amino acids is called a ______________ bond.

the bond forms between the ____________ and _____________ atoms.

a molecule with many amino acids is called a _______________________
LEVELS OF STRUCTURE

Proteins have very specific shapes. The shape of a protein determines its function in the body.

If the shape is altered or deformed, the function is lost. This is because proteins usually function by interacting with
other molecules and binding to them much like one puzzle piece fits perfectly with another puzzle piece.

Proteins can denature if exposed to certain chemicals or to heat

Once the long chain of amino acids (as many as 1000) has been created, the polypeptide undergoes several stages
before it reaches its final complex structure:
o
___________ Structure: the completed linear polypeptide chain
o
___________ Structure: the polypeptide folds onto itself forming a) an -helix b) a -sheet c) random
coil
o
___________ Structure: the secondary structure folds onto itself held by ionic, covalent, hydrogen and/or
non-polar bonds. Covalent bonds are formed between sulfur atoms creating disulfide bridges.
o
___________ Structure: results when different folded polypeptide chains interact with each other
Proteins Complexed With Metal Ions


Hemoglobin is a protein formed by the combination of 4 polypeptide chains (quaternary structure)
Hemoglobin carries oxygen in red blood cells….how?