Name ________________________________
IB Biology I Molecular Biology Practice
1. What is the difference between hydrolysis and
condensation?
Hydrolysis is the breaking apart of a molecule
with water and condensation is the removal of
water to connect two smaller molecules
2. List the functions of proteins.
a) catalyst
b) muscle contraction
c)cytoskeleton
d) tensile strengthening
e) blood clotting
f) transport of nutrients and gases
g) cell adhesion
h) membrane transport
i) hormones
j) receptors
k) packing of DNA
l) immunity
3. Draw an amino acid.
4. Draw a dipeptide.
5. How does an enzyme increase the rate of a
reaction?
They lower the reaction rate allowing the reaction to
proceed faster because it needs less energy to start.
6. Describe what happens to enzymatic activity as the
substrate concentration is increase.
The enzyme activity will increase until all the enzyme is
bound up and then the reaction rate will level off.
When the reation is complete the enzyme is free to
attach to another substrate
7. Draw a fatty acid.
8. How could you cause an enzyme to denature?
High temperatures, a non optimal pH
9. What determines the specificity of an enzyme for a
substrate?
The active site on the enzyme, which fits into the
substrate exactly.
10. State the names of two monosaccharides, two
disaccharides, and two polysaccharides.
Monosaccharides: Glucose, fructose ,ribose
Disaccharides: lactose, sucrose
polysaccharide: Amylose (starch), Amylopectin,
Glycogen (animal storage polymer), Cellulose,
11. Define hydrogen bond.
A hydrogen bond is the electromagnetic attraction created
between a partially positively charged hydrogen atom
attached to a highly electronegative atom and another
nearby electronegative atom. A hydrogen bond is a type of
dipole-dipole interaction; it is not a true chemical bond.
12. What is the role of carbohydrates in animals?
They are a source of energy
13. Draw glucose.
14. Draw ribose.
15. Explain the induced fit model of enzymatic action.
This is when the substrate will change slightly to fit
the enzymes active site
16. Define active site.
a region on an enzyme that binds to a protein or
other substance during a reaction.
17. What is a proteome?
The set of proteins present in an organism under a
given set of environmental conditions.
18. Draw and label a graph that shows the activity of
an enzyme as the temperature increases.
19. Explain why water has a high boiling point.
The extra hydrogen bonds found in a sample of
water will increase the boiling point and cause it to
have a low vapor pressure. In a state of
equilibrium, vapor pressure pertains to the
pressure exerted by a vapor on the liquid from
which it evaporated. Vapor pressure forms an
indirect correlation with intermolecular forces,
where increasing forces result to a decrease in
vapor pressure and decreasing forces result with an
increasing in vapor pressure.
20. What is the one gene-one polypeptide hypothesis?
For every polypeptide formed there is only one
gene.
21. What is the difference between anabolism and
catabolism?
Anabolism: the synthesis of complex molecules in
living organisms from simpler ones together with
the storage of energy; constructive metabolism.
Catabolism: the breakdown of complex molecules
in living organisms to form simpler ones, together
with the release of energy; destructive metabolism.
22. How did the artificial synthesis of urea disprove
vitalism?
When a compound was produced outside the living
organism, scientists realized that the vital force
(soul or spirit of an organism) was not needed.
23. What type of bond does carbon make?
Covalent Bond
24. Draw four water molecules and their hydrogen
bonds.
25. Explain how the properties of water allow it to act
as a coolant.
the high specific heat value of water, this means that
the amount of heat per unit mass of water required to
raise its temperature by 1 degree Celsius is quite high.
In other words, a small quantity of water can absorb a
large amount of heat which is the definition of a good
coolant.