PEARSON EDEXCEL AS/A-LEVEL
BIOLOGY EXAM | LATEST QUESTIONS
AND ANSWERS, UPDATED STUDY GUIDE
2026/2027
What are organic compounds?
Compounds that always contain carbon. Also contain hydrogen and oxygen.
Form carbohydrates, lipids and proteins.
Polar molecule
A molecule in which one side of the molecule is slightly negative and the
opposite side is slightly positive
Dissociation
The separation of ions that occurs when an ionic compound dissolves
Page | 1
,ATP
Adenosine triphosphate. Energy.
ADP
(Adenosine Diphosphate) The compound that remains when a phosphate group
is removed from ATP, releasing energy
What is the angle size between the 2 dipoles in a water molecule?
104.5
Hydrogen Bonds
Weak electrostatic intermolecular bonds between polar molecules that contain
at least 1 hydrogen atom
How many bonds can carbon form?
4 - usually forming a tetrahedral shape.
Page | 2
,Molecular shapes
Straight lines = not facing towards or away from you
Dotted lines = facing away from you
Triangle lines = facing towards you
Monomers
small unit that can join together with other small units to form polymers
Polymers large compound formed from combinations of many monomers
Macromolecules
A very large organic molecule composed of many smaller molecules
Carbohydrates the starches and sugars present in foods
Page | 3
, disaccharides
Carbohydrates that are made up of two monosaccharides, sucrose, lactose,
maltose.
formula of monosaccharides
(CH2O)n
Tricose
n = 3 : C3H6O3
Hexose
n=6 : C6H12O6
Page | 4
BIOLOGY EXAM | LATEST QUESTIONS
AND ANSWERS, UPDATED STUDY GUIDE
2026/2027
What are organic compounds?
Compounds that always contain carbon. Also contain hydrogen and oxygen.
Form carbohydrates, lipids and proteins.
Polar molecule
A molecule in which one side of the molecule is slightly negative and the
opposite side is slightly positive
Dissociation
The separation of ions that occurs when an ionic compound dissolves
Page | 1
,ATP
Adenosine triphosphate. Energy.
ADP
(Adenosine Diphosphate) The compound that remains when a phosphate group
is removed from ATP, releasing energy
What is the angle size between the 2 dipoles in a water molecule?
104.5
Hydrogen Bonds
Weak electrostatic intermolecular bonds between polar molecules that contain
at least 1 hydrogen atom
How many bonds can carbon form?
4 - usually forming a tetrahedral shape.
Page | 2
,Molecular shapes
Straight lines = not facing towards or away from you
Dotted lines = facing away from you
Triangle lines = facing towards you
Monomers
small unit that can join together with other small units to form polymers
Polymers large compound formed from combinations of many monomers
Macromolecules
A very large organic molecule composed of many smaller molecules
Carbohydrates the starches and sugars present in foods
Page | 3
, disaccharides
Carbohydrates that are made up of two monosaccharides, sucrose, lactose,
maltose.
formula of monosaccharides
(CH2O)n
Tricose
n = 3 : C3H6O3
Hexose
n=6 : C6H12O6
Page | 4
