Download Remember: Condensation makes bonds: Hydrolysis breaks bonds.

IB Biology 3.2 Carbohydrates, Lipids, Proteins
Highlight all Command Terms!
1. Define organic molecule.
• “Organic compounds are based on carbon and are found in living things.” (1)
2. List three carbon-containing groups or molecules that are not organic.
There are many organic molecules in living things. The same (or very similar) molecules are used in many
different living things for the same purpose.
3. Saccharides are sugars and carbohydrates. Sugars (monosaccharides and disaccharides) are used
to build up carbohydrates (polysaccharides).
a. State what happens to the structure of monosaccharides when they are placed in water.
b. Draw the simplified (ring) structures of glucose and ribose. Number the carbon atoms
correctly.
Condensation of monosaccharides is a polymerization reaction. It can continue to create a longer chain
of saccharides (a carbohydrate). These building reactions are anabolic metabolism.
c. Annotate and complete diagram below to outline how two monosaccharides are
converted into a disaccharide through condensation, producing a glycosidic bond.
Include a word equation.
What else is needed to make the reaction occur?
d. Complete the table below:
-saccharides
examples
Glucose
Mono-
Plant or animal?
Function/ uses
animal
Quickly absorbed and used in
respiration
Galactose
plant
plant
Lactose
Di-
animal
animal
Poly-
Dimer of glucose, broken down from
starch.
Insoluble storage of glucose in the
liver, produced using insulin.
Starch
plant
Structural unit in plant cell walls
e. Outline this reaction using an example of a dimer of two pentose sugars. Explain the
relevance of the name of the reaction.
Remember: Condensation makes bonds: Hydrolysis breaks
4. Fatty acids and glycerol are used in the production of triglycerides.
a. Draw the generalized structures of fatty acids and glycerol.
b. Outline the relevance of the following properties of lipids.
Energy storage*
Thermal insulation*
Protection
Buoyancy
bonds.
IB Biology 3.2 Carbohydrates, Lipids, Proteins
Membranes
Hormones
*Essential exam examples
c. Write a word equation for the formation of one triglyceride from fatty acids and
glycerol.
d. Outline how condensation reactions produce one triglyceride molecule (including the
name of the bonds produced):
e. Explain why condensation of fatty acids and glycerol to produce a triglyceride is not an
example of polymerization.
f. Compare lipids and carbohydrates in terms of energy storage:
carbohydrates
lipids
Stored as…?
Long/short term storage?
Ease of digestion/ release of
energy?
Energy per gram?
Solubility in water?
(and consequence)
Use of oxygen in
metabolism?
(and consequence)
5. Proteins are the tertiary (or quaternary) structure of polypeptides, polymers of amino acids.
a. In the space below, draw the structure of a general amino acid. Include (and label) the
amine group, carboxyl group and ‘R’ group.
b. There are ____ different amino acids, each coded for by a triplet of bases on DNA. The
R-group is the region of variation between the amino acids and determines its
properties.
c. Use a diagram to show condensation and hydrolysis of peptides.