AQA A-Level Biology Topic 1: Biological
Molecules Latest Update 2026/2027
What are monomers? - Answer--Monomers are *small units* which are the
components of larger molecules.
What are polymers? - Answer--Polymers are molecules made from *many
monomers* joined together.
What are examples of monomers? - Answer--*Monosaccharides, amino acids* and
*nucleotides*
What are examples of polymers? - Answer--*Polysaccharides, polypeptides* and
*polynucleotides*
What reaction allows two monomers to bond together? - Answer--A *condensation
reaction* allows *two monomers* to be joined together by a chemical bond,
*releasing a water molecule*.
What reaction breaks the chemical bond between two molecules? - Answer--A
*hydrolysis reaction* allows the chemical bond to break between two molecules and
this happens due to the *addition of water*.
What are carbohydrates? - Answer--Carbohydrates are molecules which consist only
of *carbon, hydrogen and oxygen*.
What is the small unit that makes up a carbohydrate. - Answer--Monosaccharides
What is formed when two monosaccharides go through condensation reaction? -
Answer--A *disaccharide* is formed.
What is the special bond that is formed during the condensation reaction between
two monosaccharides? - Answer--A *glycosidic bond*
What is formed when many monosaccharides go through condensation reaction? -
Answer--A *polysaccharide* is formed.
What are examples of monosaccharides? - Answer--- *Glucose* (*α-glucose* and *β
glucose*)
, - *Galactose*
- *Fructose*
What is the structure of both α-glucose and β glucose? - Answer--They both have *6
carbon atoms*, α-glucose has its OH group attached at the *bottom right* and β
glucose has its OH group attached at the *top right*.
Which disaccharide is formed when two α-glucose molecules join together? -
Answer--Maltose
Which disaccharide is formed when a glucose molecule and fructose join together? -
Answer--Sucrose
Which disaccharide is formed when a glucose molecule and galactose join together?
- Answer--Lactose
What are the three polysaccharides that are formed from glucose monomers? -
Answer--- *Glycogen* (formed by the condensation of α-glucose)
- *Starch* (formed by the condensation of α-glucose)
- *Cellulose* (formed by the condensation of β glucose)
What is starch? - Answer--Starch is what plants *store as excess glucose*. When
plants require glucose for respiration and energy, starch is broken down into glucose.
What mixture does starch consist of? - Answer--*Amylose* and *Amylopectin*
Describe the structure of starch? - Answer--Amylose is a *long, unbranched chain of
α-glucose* molecules. Due to its specific glycosidic bonding, its shape becomes
*coiled*, which makes it very *compact*.
Amylopectin is a *long, branched chain of α-glucose* molecules. It has got many
*side branches* on it.
Explain the relationship between the structure and function in starch. - Answer--The
coiled and compact shape of amylose allows a *lot of energy to be stored*, therefore
making it good for energy storage.
The side branches on amylopectin allow *enzymes to break down* the molecule and
make it *easier to break the glycosidic bond*. This means that energy can be
*released quicker* for important functions like *respiration*.
Molecules Latest Update 2026/2027
What are monomers? - Answer--Monomers are *small units* which are the
components of larger molecules.
What are polymers? - Answer--Polymers are molecules made from *many
monomers* joined together.
What are examples of monomers? - Answer--*Monosaccharides, amino acids* and
*nucleotides*
What are examples of polymers? - Answer--*Polysaccharides, polypeptides* and
*polynucleotides*
What reaction allows two monomers to bond together? - Answer--A *condensation
reaction* allows *two monomers* to be joined together by a chemical bond,
*releasing a water molecule*.
What reaction breaks the chemical bond between two molecules? - Answer--A
*hydrolysis reaction* allows the chemical bond to break between two molecules and
this happens due to the *addition of water*.
What are carbohydrates? - Answer--Carbohydrates are molecules which consist only
of *carbon, hydrogen and oxygen*.
What is the small unit that makes up a carbohydrate. - Answer--Monosaccharides
What is formed when two monosaccharides go through condensation reaction? -
Answer--A *disaccharide* is formed.
What is the special bond that is formed during the condensation reaction between
two monosaccharides? - Answer--A *glycosidic bond*
What is formed when many monosaccharides go through condensation reaction? -
Answer--A *polysaccharide* is formed.
What are examples of monosaccharides? - Answer--- *Glucose* (*α-glucose* and *β
glucose*)
, - *Galactose*
- *Fructose*
What is the structure of both α-glucose and β glucose? - Answer--They both have *6
carbon atoms*, α-glucose has its OH group attached at the *bottom right* and β
glucose has its OH group attached at the *top right*.
Which disaccharide is formed when two α-glucose molecules join together? -
Answer--Maltose
Which disaccharide is formed when a glucose molecule and fructose join together? -
Answer--Sucrose
Which disaccharide is formed when a glucose molecule and galactose join together?
- Answer--Lactose
What are the three polysaccharides that are formed from glucose monomers? -
Answer--- *Glycogen* (formed by the condensation of α-glucose)
- *Starch* (formed by the condensation of α-glucose)
- *Cellulose* (formed by the condensation of β glucose)
What is starch? - Answer--Starch is what plants *store as excess glucose*. When
plants require glucose for respiration and energy, starch is broken down into glucose.
What mixture does starch consist of? - Answer--*Amylose* and *Amylopectin*
Describe the structure of starch? - Answer--Amylose is a *long, unbranched chain of
α-glucose* molecules. Due to its specific glycosidic bonding, its shape becomes
*coiled*, which makes it very *compact*.
Amylopectin is a *long, branched chain of α-glucose* molecules. It has got many
*side branches* on it.
Explain the relationship between the structure and function in starch. - Answer--The
coiled and compact shape of amylose allows a *lot of energy to be stored*, therefore
making it good for energy storage.
The side branches on amylopectin allow *enzymes to break down* the molecule and
make it *easier to break the glycosidic bond*. This means that energy can be
*released quicker* for important functions like *respiration*.
