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AS Human Biology Unit 3
Text questions
| P38/Q1 | a) b) c) |
monomer = fat polymer = starch macromolecule = protein |
| P39/Q2 |
6 + 6 = 12 |
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| P40/Q3 |
C12H22O11 |
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| P41/Q4 |
All starches are polymers of alpha glucose with
glycosidic bonds between C1 and C4 of adjacent
glucose molecules. Starches from different plants
will differ due to:
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| P42/Q5 |
Food intake is generally higher for males than for
females. Starch rich foodstuffs form the basis of
the most common diets hence starch intake is higher
in males. |
|
| P43/Q6 |
Protein perform many functions, eg. structural,
functional (enzymes). There are many different types
of proteins designed to perform structural functions
and there are many different proteins which serve as
enzymes controlling various metabolic processed
within the cell. |
|
| P44/Q7 |
8 |
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| P44/Q8 |
N-terminus → a free
amino group (NH2), i.e. not engaged in the formation
of a peptide bond. C-terminus → a free carboxyl group (COOH), not engaged in the formation of a peptide bond. |
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| P45/Q9 |
(b) & (d) |
|
| P48/Q10 |
A vaccine (inactive influenza viruses) stimulates
some of the WBC to produce influenza antibodies.
These antibodies will defend the person if he/she is
exposed to living influenza viruses. An antibody is
a protein. The structure of this protein matches
some protein features found on the surface of the
virus. «1968» strains of influenza virus have
different protein features than «1985» strains.
Therefore «1968» antibodies will not match
«1985» strains of the virus. Therefore «1968»
antibody will not defend a person exposed to the
«1985» virus. |
|
| P49/Q11 |
Fatty acid with at least two double bonds (C = C) in
the hydrocarbon chain. |
|
| P50/Q12 |
Triglyceride: 1 molecule of glycerol plus 3
molecules of fatty acids. Molecule of a triglyceride
is non-polar and it does not mix with water
(hydrophobic). Phospholipid: 1 molecule of glycerol + 2 molecules of fatty acids + 1 phosphate group. Molecules of fatty acids are non-polar (hydrophobic). Phosphate group is polar (hydrophilic). |
|
| P51/Q13 |
Monounsaturated. |
|
| P52/Q14 |
The distance moved by substance is a fraction of the
distance moved by solvent front. |
Assignment
| P54/Q1 | Figures are given per 100g of milk because it is
a standard way of providing this information ("nutritional value"), which was accepted by the industry. This standard enables comparisons to be made easily. It also allows a quick expression of values as %. |
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| P54/Q2 | a) b) |
Carbon is oxidised: C + O2
→ CO2. Ash represents mineral salt/ions content in milk. |
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| P54/Q3 | ? EMPTY |
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| P54/Q4 | a) | 10.8kg - 100% 34.4kg - ? ? = (34.4 x 100) / (10.8) = 318.5% Very high protein content → synthesis of new proteins for tissue/body building. Very high fat content → synthesis of seal's own fat/adipose tissue. High ash content → ions (Ca2+) used in bone building. |
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| P55/Q5 | a) b) |
They have no double bonds in their
hydrocarbon chain. Total concentration of saturated and unsaturated fatty acids in mg per g of milk produced.
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| c) | The concentration of saturated fatty acids (SFA) in
the milk produced by vegans is lower than the
concentration of SFA in the milk produced by the
control group. The reason for the difference is the
diet. Vegans eat exclusively non-animal foodstuffs
(vegetarian diet). Fats produced by plants have a
much higher concentration of unsaturated fatty acids
than fats of animal origin, which are eaten by the
control group, (hence higher saturated fatty acid
content in the milk of the control group). The
concentration of unsaturated fatty acids (UFA) in
the milk of vegans is higher than that of the
control group because of the reason given above. |
Examinations
| P56/Q1 | a) |
Glycerol 3C. |
| b) |
(i) The smallest molecule of an amino acid is
It contains 2C. |
|
| c) |
During the reaction molecules of water are removed
and as result a new (glycosidic) bond
between adjacent glucose molecules can be formed,
joining these two molecules together. Water molecule
is removed to condense two (glucose)
molecules into one larger molecule. |
|
| P56/Q2 | a) |
A strip of chromatography paper - pencil line ruled
to show the origin - a spot of the substance is
build up gradually on the origin by transferring
small drop of a solution of the substance at a
time, drying it up, transferring another one, and so
on - the paper is fastened with a drawing pin to a
bung and placed in a boiling tube with some amount
of solvent inside - care needs to be taken to ensure
that the spot is suspended above the level of the
solvent - the completed chromatogram is examined and
the distances A(moved by substance) and B (moved by
solvent front) are measured to enable calculation of
the Rf value. |
| b) |
(i) A certain amount of fatty acids remains on the
chromatography paper before the maximum height
("distance moved by substance") is reached. (ii) The level of radioactivity measured in this case is determined by the number of radioactive atoms of C. Hence, the larger the molecule of the fatty acid, the higher number of radioactive C atoms in its hydro-carbon chain and, consequently, the higher total level of the molecule's radioactivity. |
