AQA A Level Biology
Paper 1 Questions &
Answers
2025/26
Water removed from the reactants
Condensation
The addition of water to the reactants
Hydrolysis
Add 2cm³ of food sample (in solution). Add 2cm³ of benedict's Reagent. Heat the
solution in a water bath for 3 minutes. Change from blue to brick red. CuO formed
Test for Reducing Sugars
Add 2cm³ of food sample.Add 2cm³ of dilute HCL then heat.Add 2cm³ of
NaHCO3.Then do test for reducing sugars.
Non-Reducing Sugars
Add drops of iodine to starch solution. Colour change to blue-black
Test for Starch
Mix Test solution with ethanol. Shake for 1 minute. Add water. Cloudy white
,emulsion
Test for Lipids
Equal volumes of Test solution and NaOH. Add a few drops of biuret solution
(dilute copper (II) sulphate solution). Colour change to mauve/purple
, Test for Proteins
1. Inhibitor is similar in shape to substrate so it impermanently binds to the active
site.
2. Prevents ESC from forming, slowing rate
Competitive inhibition (2)
1. Molecule will bind to allosteric site.
2. Binding causes a change in active site.
3. Permanently preventing further ESC.
Non-competitive inhibition (3)
1. DNA helicase breaks the hydrogen bonds between the base pairs
2. 2 single strands formed as the double helix "unzips".
3. Free nucleotides in the nucleoplasm bond to the complementary bases on the
strand.
4. DNA polymerase joins the new strands together by creating phosphodiester
bonds.
DNA Replication: Semiconservative (4)
Adenosine triphosphate is a molecule that releases a small amount of energy
when hydrolysed
ATP
Prevents the cell from drying out. Allows bacteria to stick to each other
Slime capsule (2)
Used for attachment of a cell to a surface
Fimbria
Involved in bacterial conjugation
Pilli
Paper 1 Questions &
Answers
2025/26
Water removed from the reactants
Condensation
The addition of water to the reactants
Hydrolysis
Add 2cm³ of food sample (in solution). Add 2cm³ of benedict's Reagent. Heat the
solution in a water bath for 3 minutes. Change from blue to brick red. CuO formed
Test for Reducing Sugars
Add 2cm³ of food sample.Add 2cm³ of dilute HCL then heat.Add 2cm³ of
NaHCO3.Then do test for reducing sugars.
Non-Reducing Sugars
Add drops of iodine to starch solution. Colour change to blue-black
Test for Starch
Mix Test solution with ethanol. Shake for 1 minute. Add water. Cloudy white
,emulsion
Test for Lipids
Equal volumes of Test solution and NaOH. Add a few drops of biuret solution
(dilute copper (II) sulphate solution). Colour change to mauve/purple
, Test for Proteins
1. Inhibitor is similar in shape to substrate so it impermanently binds to the active
site.
2. Prevents ESC from forming, slowing rate
Competitive inhibition (2)
1. Molecule will bind to allosteric site.
2. Binding causes a change in active site.
3. Permanently preventing further ESC.
Non-competitive inhibition (3)
1. DNA helicase breaks the hydrogen bonds between the base pairs
2. 2 single strands formed as the double helix "unzips".
3. Free nucleotides in the nucleoplasm bond to the complementary bases on the
strand.
4. DNA polymerase joins the new strands together by creating phosphodiester
bonds.
DNA Replication: Semiconservative (4)
Adenosine triphosphate is a molecule that releases a small amount of energy
when hydrolysed
ATP
Prevents the cell from drying out. Allows bacteria to stick to each other
Slime capsule (2)
Used for attachment of a cell to a surface
Fimbria
Involved in bacterial conjugation
Pilli
