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Molecules, Biodiversity, Food and Health
Biological Molecules
Biological Molecules
(a) describe how hydrogen bonding occurs between water molecules, and relate this, and other properties of
water, to the roles of water in living organisms;
Water is a polar molecule. This is because the oxygen atom pulls the shared electrons towards…

Page 2

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Molecules, Biodiversity, Food and Health
(c) describe, with the aid of diagrams, the formation and breakage of peptide bonds in the synthesis and
hydrolysis of dipeptides and polypeptides;
Synthesis
The ­OH from one amino acid and the ­H from the ­COOH from the other are removed to
make water, and…

Page 3

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Molecules, Biodiversity, Food and Health
(m) compare and contrast the structure and functions of starch (amylose) and cellulose;
Amylose
Made up of -glucose
Straight chain
Tends to coil up
Plant storage polysaccharide
Cellulose
Made up of -glucose
In a chain, alternate glucose subunits are inverted
Forms straight chains
The -glycosidic…

Page 4

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Molecules, Biodiversity, Food and Health
(r) describe how the concentration of glucose in a solution may be determined using colorimetry
Benedict's test reveals the presence of reducing sugars
It results in an orange-brown precipitate
The more reducing sugar there is present, the more precipitate will be formed and the
more…

Page 5

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Molecules, Biodiversity, Food and Health
(c) describe, with the aid of diagrams, the mechanism of action of enzyme molecules, with reference to
specificity,
The active site of an enzyme is a specific shape, depending on the reaction that it catalyses,
meaning that other molecules won't fit into the active site…

Page 6

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Molecules, Biodiversity, Food and Health
(e) describe how the effects of
pH,
A starch-agar plate is made up by mixing starch with agar. The mixture is poured into a
petridish and left to set. It forms a semi-rigid gel in the plate.
Cut wells into each plate using a cork…

Page 7

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Molecules, Biodiversity, Food and Health
Coenzymes
Small, organic, non-protein molecules that bind for a short period of time to the active site.
They may bind just before, or at the same time, as the substrate binds. In many reactions,
coenzymes take part in the reaction, and like substrate, are changed…

Page 8

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Molecules, Biodiversity, Food and Health
Food & Health
Diet & Food Production
(a) define the term balanced diet;
A diet that contains all the nutrients of the nutrients requires for health and growth.
(b) explain how consumption of an unbalanced diet can lead to malnutrition, with reference to obesity;
Malnutrition…

Page 9

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Molecules, Biodiversity, Food and Health
(h) describe how the use of fertilisers and pesticides with plants and the use of antibiotics with animals can
increase food production;
Fertilisers
Replace minerals in the soil which may have been removed by the previous crops. They
contain Nitrate, Phosphate and Potassium. They increase…

Page 10

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Molecules, Biodiversity, Food and Health
(c) describe the causes and means of transmission of malaria, AIDS/HIV and TB (knowledge of the symptoms
of these diseases is not required);
Malaria
If the host already has malaria, the female anopheles mosquito will suck the parasite
gametes into its own stomach
The gametes…

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chelsie

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first of all that's AS not A2... maybe an improvement would be to study the right content..

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