IGCSE Biology
2026 - 2028
Syllabus Checklist
Topic 4: Biological Molecules
Chemical Composition
List the chemical elements
that make up carbohydrates
, fats
, and proteins
.
Large Molecules from Smaller Units
State that large molecules
are made from smaller molecules
, limited to:
▪ Starch
, glycogen
, and cellulose
from glucose
.
▪ Proteins
from amino acids
.
▪ Fats
and oils
from fatty acids
and glycerol
.
Food Tests
Describe the use of:
▪ Iodine solution
test for starch
.
▪ Benedict’s solution
test for reducing sugars
.
▪ Biuret test
for proteins
.
▪ Ethanol emulsion test
for fats
and oils
.
▪ DCPIP test
for vitamin C
.
DNA Structure
Describe the structure of a DNA molecule
:
▪ Two strands coiled together to form a double helix
.
▪ Each strand contains chemicals called bases
.
▪ Bonds
between pairs of bases hold the strands together.
▪ The bases always pair in the same way: A with T
and C with G
.
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