Download Assignment # Carbohydrates

Proteins
GT Biology
I. Proteins are compounds made of
carbon, hydrogen, nitrogen, and oxygen
A. Proteins
1. sometimes contain sulfur and
phosphorous
2. can have the ending “-in”
ex: insulin, gastrin, hemoglobin
3. are very versatile
4. make LIFE possible
B. Proteins function as
1. Structural parts of cells & body
tissues
Ex: Cartilage, bones, muscles
2. Hormones – chemical messengers
3. Antibodies – protect body from
foreign substances
4. Enzymes – speed up chemical
reactions (end in “-ase”)
5. Protection
ex: hair, turtle shell, horns, hooves
Sources of Proteins as food
Eggs
Dairy
Beans and Nuts
Meat
Fish
II. The building blocks of proteins are
amino acids (AA’s)
A. Central carbon atom bonded to:
1. 1 Carboxyl group
2. 1 amino group
3. 1 hydrogen
4. 1 side chain
?
B. There are 20 different kinds of
amino acids (usually end in “-ine”)
III. How proteins are formed
A. Proteins are formed by dehydration
synthesis (sound familiar?)
*link amino acids together
One AA loses an “OH”, one loses an “H”
forming a dipeptide and water. This
can continue to link many AA
together = a protein
B. The bond between two amino acids
is a peptide bond
water
dipeptide
H2O
C. Dipeptide – a molecule composed of
2 amino acids
D. Polypeptide – a molecule composed
of more than 2 amino acids
1. The smallest protein has 50 amino
acids
2. The largest protein has over 100,000
amino acids
V.
The structure of a protein
determines its function
A. Coils or helixes (one chain)
B. Pleated sheets (One chain)
C. Globular (many chains together)
globular
How do you test for a Protein?
The Biuret test:
* add a small amount of
Biuret solution to the sample. If
it contain protein, it will
turn purple
Lab book entry
Construct a Venn diagram comparing
and contrasting Carbohydrates, Lipids,
and Proteins.
carbo
What the
Two have in
common
What they all
have in
common.
Unique features
lipid
protein