MCV4U UNIT 4 – EXTENSIONS
ASSESSMENT OF LEARNING FINAL
TEST 2026 QUESTIONS WITH
CORRECT ANSWERS GRADED A+
◍ What 4 factors affect enzyme activity?.
Answer: 1. Temperature2. pH3. Enzyme concentration4. Substrate
concentration
◍ How is a control set up in a practical measuring enzyme activity?.
Answer: Replace the enzyme solution with distilled water or boiled enzyme
solution
◍ Give the 2 types of molecule from which a ribosome is made (2).
Answer: 1. ribosomal Proteins2. ribosomal RNA
◍ How can the results be used to find the initial rate of reaction?.
Answer: -Plot results on a graph of rate against time-Draw a tangent at
time=0 and find the gradient
◍ Describe the role of a ribosome in the production of a polypeptide. Do not
include transcription in your answer (3).
Answer: 1. mRNA binds to ribosome2. allows tRNA with anticodons to
bind3. catalyses formation of polypeptide bond between amino acids
◍ Complete the complementary base sequence of DNA strand from which
pre-mRNA may be transcribed:ACGCAUUAU (1).
Answer: TGCGTAATA
◍ In a eukaryotic cell, the base sequence of the mRNA might be different from
the sequence of the pre-mRN
A. Explain why (2).
, Answer: 1. introns in pre-mRNA2. splicing
◍ Outline the practical procedure to measure the effect of temperature on
enzyme activity, using catalase and hydrogen peroxide.
Answer: 1. Add equal volumes of catalase to test tubes in water baths of
differing temperatures (this allows their temperatures to be constant)2. Add
a known volume of hydrogen peroxide to a test tube and place a delivery
tube on after3. Record the number of bubbles formed during the reaction for
a set amount of time, and repeat the experiment using the varying
temperatures of the water baths
◍ Describe the structure of glycogen (2).
Answer: 1. polysaccharide of alpha glucose2. joined by glycosidic bonds
◍ Suggest how glycogen acts as a source of energy (2).
Answer: 1. hydrolysed to glucose2. glucose is used in respiration
◍ How is the rate of reaction calculated using time?.
Answer: 1/time
◍ Suggest and explain two ways the cell0surface membranes of the cells lining
the uterus may be adapted to allow rapid transport of nutrients (2).
Answer: 1. membrane folded so increased surface area2. larger number of
protein channels for facilitated diffusion3. large number of protein carriers
for active transport4. large number of protein for co-transport
◍ Sodium ions from salt (sodium chloride) are absorbed by cells lining the gut.
Some of these cells have membranes with a carrier protein called NHE3.
NHE3 actively transports one sodium ion into the cell in exchange for one
promo (hydrogen ion) out of the cell. Use your knowledge of transport
across cell membranes to suggest how NHE3 does this (3).
Answer: 1. co-transport2. uses hydrolysis of ATP3. sodium ion and proton
bind to the protein4. protein changes shape
◍ What is the effect of temperature on enzyme activity?.
Answer: -As temperature increases, particles are provided with more kinetic
energy. This leads to a higher rate of successful collisions and the formation
, of ES complexes.-Beyond the optimum temperature tertiary structure is
altered leading to the enzyme being denatured and unable to create ES
complexes
◍ High absorption of salt from the diet can result in a higher than normal
concentration of salt in the blood plasma entering capillaries. This can lead
to a build-up of tissue fluid. Explain how (2).
Answer: 1. higher salt results in lower water potential of tissue fluid2. so
less water returns to capillary by osmosis at venue end
◍ What are the risks associated with using enzymes?.
Answer: -Allergic reaction-Wear eye protection
◍ What is a monomer?.
Answer: Small, basic molecular units that can form a polymer
◍ What is a polymer?.
Answer: Large, complex molecules composed of long chains of monomers
joined together
◍ Give at least two examples of a monomer.
Answer: MonosaccharidesAmino acidsNucleotides
◍ Give at least two examples of a polymer.
Answer: ProteinsCarbohydratesDNA
◍ Describe how bacteria divide (2).
Answer: 1. binary fission 2. replication of circular DNA3. division of
cytoplasm to produce 2 daughter cells4. each with single copy of circular
DNA
◍ Suggest one advantage to a bacterium of secreting an extracellular protease
in its natural environment (2).
Answer: 1. to digest protein2. so they can absorb amino acids for protein
synthesis
◍ What is a condensation reaction?.
Answer: Chemical bond is formed between two monomers, producing a
, molecule of water
◍ Mammals have some cells that produce extracellular proteases. They also
have cells with membrane-bound dipeptidases. Describe the action of these
membrane-bound dipeptidases and explain their importance (2).
Answer: 1. hydrolyse peptide bonds to release amino acids2. amino acids
can cross cell membrane
◍ Suggest why human ATP synthase is not inhibited and bacterial synthase is
inhibited (1).
Answer: 1. human ATP synthase has a different shape active site to bacterial
ATP synthase
◍ Give 3 environmental variables that should be controlled when growing the
plants before treatment with the different sprays (2).
Answer: 1. carbon dioxide concentration2. light intensity3. temperature
◍ The scientists incubated the flasks containing the leaf discs at 26C and
gently shook the flasks. Suggest one reason why the scientists ensured the
temperature remained constant and one reason why the leaf discs were
shaken (2).
Answer: 1. temperature - so rate of diffusion remains constant2. shaking - so
all surfaces of the leaf discs are exposed
◍ What is a hydrolysis reaction?.
Answer: Breaking a chemical bond using a molecule of water to produce
smaller molecules
◍ Describe how phagocytosis of a virus leads to presentation of its antigens
(3).
Answer: 1. phagosome guess with lysosome2. virus destroyed by
lysozymes3. peptides from virus are displayed on the cell membrane
◍ Describe how presentation of a virus antigen leads to secretion of an
antibody against this virus antigen (3).
Answer: 1. helper T cells bind to the antigen2. this stimulates a specific B
cell3. B cell clones
ASSESSMENT OF LEARNING FINAL
TEST 2026 QUESTIONS WITH
CORRECT ANSWERS GRADED A+
◍ What 4 factors affect enzyme activity?.
Answer: 1. Temperature2. pH3. Enzyme concentration4. Substrate
concentration
◍ How is a control set up in a practical measuring enzyme activity?.
Answer: Replace the enzyme solution with distilled water or boiled enzyme
solution
◍ Give the 2 types of molecule from which a ribosome is made (2).
Answer: 1. ribosomal Proteins2. ribosomal RNA
◍ How can the results be used to find the initial rate of reaction?.
Answer: -Plot results on a graph of rate against time-Draw a tangent at
time=0 and find the gradient
◍ Describe the role of a ribosome in the production of a polypeptide. Do not
include transcription in your answer (3).
Answer: 1. mRNA binds to ribosome2. allows tRNA with anticodons to
bind3. catalyses formation of polypeptide bond between amino acids
◍ Complete the complementary base sequence of DNA strand from which
pre-mRNA may be transcribed:ACGCAUUAU (1).
Answer: TGCGTAATA
◍ In a eukaryotic cell, the base sequence of the mRNA might be different from
the sequence of the pre-mRN
A. Explain why (2).
, Answer: 1. introns in pre-mRNA2. splicing
◍ Outline the practical procedure to measure the effect of temperature on
enzyme activity, using catalase and hydrogen peroxide.
Answer: 1. Add equal volumes of catalase to test tubes in water baths of
differing temperatures (this allows their temperatures to be constant)2. Add
a known volume of hydrogen peroxide to a test tube and place a delivery
tube on after3. Record the number of bubbles formed during the reaction for
a set amount of time, and repeat the experiment using the varying
temperatures of the water baths
◍ Describe the structure of glycogen (2).
Answer: 1. polysaccharide of alpha glucose2. joined by glycosidic bonds
◍ Suggest how glycogen acts as a source of energy (2).
Answer: 1. hydrolysed to glucose2. glucose is used in respiration
◍ How is the rate of reaction calculated using time?.
Answer: 1/time
◍ Suggest and explain two ways the cell0surface membranes of the cells lining
the uterus may be adapted to allow rapid transport of nutrients (2).
Answer: 1. membrane folded so increased surface area2. larger number of
protein channels for facilitated diffusion3. large number of protein carriers
for active transport4. large number of protein for co-transport
◍ Sodium ions from salt (sodium chloride) are absorbed by cells lining the gut.
Some of these cells have membranes with a carrier protein called NHE3.
NHE3 actively transports one sodium ion into the cell in exchange for one
promo (hydrogen ion) out of the cell. Use your knowledge of transport
across cell membranes to suggest how NHE3 does this (3).
Answer: 1. co-transport2. uses hydrolysis of ATP3. sodium ion and proton
bind to the protein4. protein changes shape
◍ What is the effect of temperature on enzyme activity?.
Answer: -As temperature increases, particles are provided with more kinetic
energy. This leads to a higher rate of successful collisions and the formation
, of ES complexes.-Beyond the optimum temperature tertiary structure is
altered leading to the enzyme being denatured and unable to create ES
complexes
◍ High absorption of salt from the diet can result in a higher than normal
concentration of salt in the blood plasma entering capillaries. This can lead
to a build-up of tissue fluid. Explain how (2).
Answer: 1. higher salt results in lower water potential of tissue fluid2. so
less water returns to capillary by osmosis at venue end
◍ What are the risks associated with using enzymes?.
Answer: -Allergic reaction-Wear eye protection
◍ What is a monomer?.
Answer: Small, basic molecular units that can form a polymer
◍ What is a polymer?.
Answer: Large, complex molecules composed of long chains of monomers
joined together
◍ Give at least two examples of a monomer.
Answer: MonosaccharidesAmino acidsNucleotides
◍ Give at least two examples of a polymer.
Answer: ProteinsCarbohydratesDNA
◍ Describe how bacteria divide (2).
Answer: 1. binary fission 2. replication of circular DNA3. division of
cytoplasm to produce 2 daughter cells4. each with single copy of circular
DNA
◍ Suggest one advantage to a bacterium of secreting an extracellular protease
in its natural environment (2).
Answer: 1. to digest protein2. so they can absorb amino acids for protein
synthesis
◍ What is a condensation reaction?.
Answer: Chemical bond is formed between two monomers, producing a
, molecule of water
◍ Mammals have some cells that produce extracellular proteases. They also
have cells with membrane-bound dipeptidases. Describe the action of these
membrane-bound dipeptidases and explain their importance (2).
Answer: 1. hydrolyse peptide bonds to release amino acids2. amino acids
can cross cell membrane
◍ Suggest why human ATP synthase is not inhibited and bacterial synthase is
inhibited (1).
Answer: 1. human ATP synthase has a different shape active site to bacterial
ATP synthase
◍ Give 3 environmental variables that should be controlled when growing the
plants before treatment with the different sprays (2).
Answer: 1. carbon dioxide concentration2. light intensity3. temperature
◍ The scientists incubated the flasks containing the leaf discs at 26C and
gently shook the flasks. Suggest one reason why the scientists ensured the
temperature remained constant and one reason why the leaf discs were
shaken (2).
Answer: 1. temperature - so rate of diffusion remains constant2. shaking - so
all surfaces of the leaf discs are exposed
◍ What is a hydrolysis reaction?.
Answer: Breaking a chemical bond using a molecule of water to produce
smaller molecules
◍ Describe how phagocytosis of a virus leads to presentation of its antigens
(3).
Answer: 1. phagosome guess with lysosome2. virus destroyed by
lysozymes3. peptides from virus are displayed on the cell membrane
◍ Describe how presentation of a virus antigen leads to secretion of an
antibody against this virus antigen (3).
Answer: 1. helper T cells bind to the antigen2. this stimulates a specific B
cell3. B cell clones
