Guided notes covering material from Topic 2.3 of the updated IB Biology syllabus for 2016 exams. Notes sequence and prompts are based on the Oxford IB Biology textbook by Allott and Mindorff.

1. IB Biology Chapter 2 Notes: Carbohydrates & Lipids (2.3) NAME:
Word Definition
Monosaccharides The monomer of carbohydrates. It means “single sugar”
Disaccharides Two monosaccharides joined together. It means “double sugar.”
Polysaccharides Three or more monosaccharides joined together. The polymer of carbohydrates.
Glycerol 3-carbon monomer of lipids. Found in fats, oils, and phospholipids
Fatty acids Long carbon chain monomer of lipids. Found in fats, oils, and phospholipids
Saturated (fatty acid) A fatty acid with single bonds between all carbon atoms.
Monounsaturated
(fatty acid)
A fatty acid with one double bond in its carbon backbone.
Polyunsaturated
(fatty acid)
A fatty acid with more than one double bond in its carbon backbone.
Cis- When the hydrogen atoms are on the same side of the carbon-carbon double bond.
Trans- When the hydrogen atoms are on different sides of the carbon-carbon double bond.
Glucose A monosaccharide found in animals. Blood sugar, used in cells for energy.
Fructose A monosaccharide found in plants—specifically fruits (“fruit sugar”)
Maltose A disaccharide found in plants and animals. Made from two glucose molecules.
Made when starch is broken down.
Sucrose A disaccharide found in plants. This is table sugar. Made of one glucose and one
fructose molecule.
Starch A polysaccharide found in plants, also called amylose. Energy storage molecule
Glycogen A polysaccharide found in animals used to store energy
Cellulose A polysaccharide found in plants used in the structure of cell walls
Lactose A disaccharide found in animals made of one glucose and one galactose molecule.
It is the sugar found in milk.
Condensation A chemical reaction that joins two molecules together through the loss of water
Body Mass Index A measure used to assess whether a person’s body mass is healthy

2. 2.3.1 Monosaccharide
monomers are linked
togetherby condensation
reactions to form
disaccharides and
polysaccharide polymers.
2.3.9 Use of molecular
visualization software to
compare cellulose, starch,
and glycogen.
2.3.5 Structure and function
of cellulose and starch in
plants and glycogen in
humans.
2.3.4 Triglycerides are
formed by condensation
from three fatty acids and
one glycerol.
2.3.7 Lipids are more
suitable for long-term energy
storage in humans than
carbohydrates.
2.3.10 Determination of
body mass index by
calculation or use of a
nomogram.
Monosaccharide:
Disaccharide:
Polysaccharide:
Describe what occurs in a condensation reaction:
In the JMol software images of monosaccharides,what color are the following atoms?
Hydrogen =
Carbon =
Oxygen =
Cellulose:
Starch:
Glycogen:
Outline reasons why lipids are betterlong-term energy storage:
State the formula for calculating BMI:
BMI Status
Under 18.5
18.5-24.9
25.0-29.9
30 and above

3. 2.3.2 Fatty acids can be
saturated,monounsaturated,
or polyunsaturated.
2.3.3 Unsaturated fatty acids
can be Cis or Trans isomers.
2.3.6 Scientific evidence for
health risks of trans-fats and
saturated fats.
2.3.8 Evaluation of evidence
and the methods used to
obtain evidence for health
claims made about lipids.
Saturated:
Monounsaturated:
Polyunsaturated:
Cis-
Trans-
Label the ‘Cis’ and ‘Trans’ configurations,below: