1.
State what is meant by a condensation reaction.
[1 mark]
- joins two molecules and releases water
JD SCIENCE
Biological molecules
Indicative marking points. Award marks for equivalent scientific or mathematical wording. Do not issue this sheet with the student worksheet.
2.
State what is meant by hydrolysis.
[1 mark]
- breaks a bond using water
3.
State what is meant by α-glucose.
[1 mark]
- hexose sugar used in starch and glycogen
4.
State what is meant by starch.
[1 mark]
- amylose and amylopectin
5.
State what is meant by cellulose.
[1 mark]
- β-glucose chains with hydrogen bonds
6.
State what is meant by a triglyceride.
[1 mark]
- glycerol + 3 fatty acids
7.
State what is meant by a phospholipid.
[1 mark]
- phosphate head + two fatty tails
8.
State what is meant by the primary structure of a protein.
[1 mark]
- sequence of amino acids
9.
State what is meant by an enzyme.
[1 mark]
- globular protein catalyst
10.
State what is meant by a nucleotide.
[1 mark]
- pentose + phosphate + base
11.
Amira is asked about a condensation reaction in a AQA Biology paper.
(a) [2 marks]
- makes polymers
(b) [3 marks]
- glycosidic, peptide, ester bonds
12.
Amira is asked about hydrolysis in a AQA Biology paper.
(a) [2 marks]
- digestion
(b) [3 marks]
- opposite of condensation
13.
Amira is asked about α-glucose in a AQA Biology paper.
(a) [2 marks]
- C₆H₁₂O₆
(b) [3 marks]
- differs from β-glucose at carbon 1
14.
Amira is asked about starch in a AQA Biology paper.
(a) [2 marks]
- plant energy store
(b) [3 marks]
- coiled, compact, insoluble
15.
Amira is asked about cellulose in a AQA Biology paper.
(a) [2 marks]
- plant cell walls
(b) [3 marks]
- high tensile strength
16.
Amira is asked about a triglyceride in a AQA Biology paper.
(a) [2 marks]
- energy store, insulation
(b) [3 marks]
- ester bonds
17.
A dipeptide is hydrolysed. How many water molecules are needed?
[3 marks]
- Final answer: 1
18.
A polypeptide has 50 amino acids. How many peptide bonds?
[3 marks]
- Final answer: 49
19.
Rf of a chromatogram spot 3.0 cm, solvent 7.5 cm
[3 marks]
- Final answer: 0.40
20.
Enzyme rate is 24 units at 20°C and 48 at 30°C. Q10
[3 marks]
- Final answer: 2
21.
A DNA strand is 12% A. Percentage T
[3 marks]
- Final answer: 12%
22.
If A=12% in DNA, percentage G
[3 marks]
- Final answer: 38%
23.
Amira carries out a AQA-style required practical linked to biological molecules. This is a typical AQA required-practical style question.
(a) [2 marks]
- Independent: the independent variable for this topic
- Dependent: the measured outcome
(b) [2 marks]
- keep all other variables constant
- so the test is fair / only one variable is changed
(c) [2 marks]
- repeat and calculate a mean / use a tighter method
24.
Amira carries out collecting valid data for biological molecules. This is a typical AQA required-practical style question.
(a) [2 marks]
- Independent: a chosen factor
- Dependent: a quantitative measurement
(b) [2 marks]
- calibrated instrument
- so the test is fair / only one variable is changed
(c) [2 marks]
- systematic error from zero error
25.
Amira carries out drawing a graph for biological molecules. This is a typical AQA required-practical style question.
(a) [2 marks]
- Independent: x-variable
- Dependent: y-variable
(b) [2 marks]
- same scale / same apparatus
- so the test is fair / only one variable is changed
(c) [2 marks]
- not drawing a line of best fit through the trend
26.
Amira carries out evaluating a method about biological molecules. This is a typical AQA required-practical style question.
(a) [2 marks]
- Independent: method change
- Dependent: precision / accuracy
(b) [2 marks]
- same sample size
- so the test is fair / only one variable is changed
(c) [2 marks]
- too few repeats
27.
Compare a condensation reaction with hydrolysis.
[4 marks]
- joins two molecules and releases water
- breaks a bond using water
- give one linked difference
28.
Compare hydrolysis with α-glucose.
[4 marks]
- breaks a bond using water
- hexose sugar used in starch and glycogen
- give one linked difference
29.
Compare α-glucose with starch.
[4 marks]
- hexose sugar used in starch and glycogen
- amylose and amylopectin
- give one linked difference
30.
Compare starch with cellulose.
[4 marks]
- amylose and amylopectin
- β-glucose chains with hydrogen bonds
- give one linked difference
31.
Apply your knowledge of a phospholipid to this situation: bilayer
[3 marks]
- bilayer
32.
Apply your knowledge of the primary structure of a protein to this situation: determined by DNA
[3 marks]
- determined by DNA