Download Chapter 2 Molecules to enzymes Multiple Choice

Chapter 2 Molecules to enzymes. MC
1.
Which molecule is a polysaccharide?
A. Cellulose
B. Fructose
C. Maltose
D. Sucrose
[31 marks]
[1 mark]
Markscheme
A
2.
Which always contains carbon, hydrogen and oxygen?
[1 mark]
I. Carbohydrate
II. Protein
III. Fat
A. I and II only
B. I and III only
C. II and III only
D. I, II and III
Markscheme
D
3.
Which molecule can be hydrolyzed?
A. Glycerol
B. Maltose
C. Fructose
D. Galactose
Markscheme
B
[1 mark]
4.
What are these molecules?
[1 mark]
Markscheme
D
5.
What property of water makes it suitable as a coolant?
A. It takes a lot of energy to increase the temperature of water.
B. It takes a lot of energy for water to evaporate.
C. Water molecules are cohesive and stick to the skin.
D. Water is a good solvent so it can transport heat from the body.
[1 mark]
Markscheme
B
6.
Which sugars are examples of a monosaccharide and disaccharide?
[1 mark]
Markscheme
D
7.
Why does exposure to high temperatures cause an enzyme to lose its biological properties?
A. The substrate blocks the active site at high temperatures.
B. The three dimensional structure of the enzyme becomes changed.
C. Chemical reactions cannot take place at high temperatures.
D. High temperatures increase the activation energy of reactions.
[1 mark]
Markscheme
B
8.
What are the most frequently occurring elements in living organisms?
A. calcium, phosphorus, iron and sodium
B. calcium, sodium, nitrogen and phosphorus
C. carbon, phosphorus, oxygen and nitrogen
D. nitrogen, carbon, oxygen and hydrogen
[1 mark]
Markscheme
D
9.
The image shows the structural formula of a molecule.
[1 mark]
What is this molecule?
A. Amino acid
B. Ribose
C. Deoxyribose
D. Lactose
Markscheme
A
10.
What is a consequence of the specific heat capacity for liquid water, ice and water vapour?
A. Less energy is needed to warm water vapour than liquid water.
B. Salt dissolves more readily in liquid water than in ice.
C. Small insects can walk on liquid water.
D. Ice floats on liquid water.
Markscheme
A
[1 mark]
11.
Which is the activation energy of a reaction when it is catalysed by an enzyme?
[1 mark]
Markscheme
A
12.
Which types of molecule are shown in the diagrams?
Markscheme
C
[1 mark]
13.
In enzyme experiments, the rate of enzyme activity often gradually decreases. What is most likely to cause this
decrease?
A. The temperature decreasing
B. The enzyme concentration decreasing
C. The pH decreasing
D. The substrate concentration decreasing
[1 mark]
Markscheme
D
14. Which are functions of lipids?
A. Hydrophilic solvent and energy storage
B. Hydrophobic solvent and membrane potential
C. Thermal insulation and energy storage
D. Thermal insulation and hydrophilic solvent
[1 mark]
Markscheme
C
15. Which molecules are monosaccharides?
[1 mark]
A. starch, glycogen, cellulose
B. sucrose, maltose, lactose
C. fructose, glucose, galactose
D. glucose, lactose, cellulose
Markscheme
C
16.
Which graph shows the effect of increasing substrate concentration on enzyme activity?
[1 mark]
Markscheme
C
17.
Which molecules show a monosaccharide and a fatty acid?
Markscheme
D
[1 mark]
18.
Which carbohydrates are used to provide energy storage in plants and animals?
[1 mark]
Markscheme
C
19.
What contributes to the structure of an enzyme?
[1 mark]
A. Sequence of bases linked by hydrogen bonds
B. Sequence of substrates linked by condensation reactions
C. Sequence of amino acids linked by peptide bonds
D. Sequence of polypeptides linked by hydrolysis reactions
Markscheme
C
20.
The diagrams show three representations of the structure of the same chemical substance.
[1 mark]
What chemical substance is shown?
A. Ribose
B. Glucose
C. Fatty acid
D. Amino acid
Markscheme
B
21.
Where in the cell do condensation reactions involving amino acids occur?
A. Nucleus
B. Golgi apparatus
C. Ribosomes
D. Lysosome
[1 mark]
Markscheme
C
22.
Between which atoms do hydrogen bonds form in water?
[1 mark]
A. Oxygen and hydrogen atoms in the same water molecule
B. Oxygen and hydrogen atoms in different water molecules
C. Hydrogen atoms in the same water molecule
D. Oxygen atoms of different water molecules
Markscheme
B
23.
Which structure represents a fatty acid?
[1 mark]
Markscheme
A
24.
The graph below shows the effect of substrate concentration on enzyme activity. What conclusion can be drawn
about section X of the graph?
A. The enzyme has started to denature and the reaction slows down.
B. The reaction has finished and the substrate has been used up.
C. The enzyme is saturated and is working at its maximum reaction rate.
D. Some of the enzyme has been consumed and the reaction has reached a plateau. .
[1 mark]
Markscheme
C
25.
Which statements correctly explain properties of water?
[1 mark]
I. Water is a useful medium for metabolic reactions as many substances dissolve in water.
II. Water is useful as a coolant as it takes a small amount of heat energy to change its temperature.
III. Water molecules are cohesive which helps water transport in the roots and stems of plants.
A. I and II only
B. I and III only
C. II and III only
D. I, II and III
Markscheme
B
26.
Which sugars are both disaccharides?
[1 mark]
A. maltose and lactose
B. lactose and fructose
C. fructose and galactose
D. galactose and maltose
Markscheme
A
27.
What type of bond is labelled X?
A. Ionic
B. Peptide
C. Covalent
D. Hydrogen
Markscheme
D
[1 mark]
28.
How does an increase in temperature affect enzyme activity?
[1 mark]
Markscheme
A
29.
Which statement describes glycogen?
[1 mark]
A. It is a hormone involved in the control of blood glucose.
B. It is a component of the cell wall in plants.
C. It is a monosaccharide converted to pyruvate during cell respiration.
D. It is a polysaccharide found in animals.
Markscheme
D
30.
Which molecular structure correctly illustrates two amino acids linked by a peptide bond?
Markscheme
C
[1 mark]
31.
What substance is represented by this structure?
[1 mark]
A. Glycerol
B. Fatty acid
C. Cellulose
D. Glycogen
Markscheme
B
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