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Water is an excellent solvent

Ionic substances such as sodium chloride dissolve easily in water because the positively
and negatively charged ions are separated
Molecules like glucose and amino acids also have charged groups and therefore dissolve
easily.
Water is liquid at room temperature(good medium)
Water has low viscosity thus…

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Amino acid peptide bond is between the amine and carboxyl group of each
Cofactors could be halogen ions



Synthesis and breaking of a polypeptide




Structure of haemoglobin- describe accumulatively

primary structure: chain of amino acids joined by peptide bonds.
secondary structure alpha / helix & small regions of beta pleated…

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And is branched, starch is stored as glucose in plants
Cellulose: made up of a long chain of glucose molecules bonded by a beta 1,4 bond. And is
unbranched, cellulose is used as the cell wall of plants
Glycogen:




There are two forms of starch, amylose and amylopectin. Glycogen is…

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Cellulose

Beta-glucose make chains called cellulose abundant in plants, they are stronger than
Amylose as every other monomer is flipped over as shown in figure 3.

Cellulose=> Hydrogen bonding=> Microfibrils=> Hydrogen bonding=> Macrofibrils

Macrofibrils are important for Turgor Pressure and the arrangement of Microfibrils
determine how guard cells work .…

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If test is positive, but does not follow the colour pattern for reducing sugars.

Iodine test for starch

Add Iodine dissolved in potassium iodide solution to sample
If starch is present, colour change brown-orange to blue-black

Biuret test for proteins

Sample is made alkaline by adding NaOH
Add copper (II)…

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Examples:

Statins- compete with cholesterol for active site of HMG-CoA reductase, a liver enzyme
which helps make cholesterol (reversible)
Penicillin (an antibiotic) can kill or inhibit the growth of microorganisms. Penicillin is an
inhibitor of a bacterial enzyme that forms cross-links in the bacterial cell wall of some
bacteria.


o…

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Pesticides: chemicals that kill pests, most are specialised, or may harm non-pests
Fungicide: reduces fungal growth in leaves and roots
Antibiotics: infected animals are treated when intensively farmed which may slow
growth and impair reproductions
Herbicides: kill plants by disrupting hormones, similar to pesticides

Food spoilage:

Visible growth of microorganisms…

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Conditions are very specific and small changes kill microorganisms

Health: a state of mental, physical and social wellbeing, not just absence of disease

Disease: a departure from good health caused by a malfunction of the mind or body

Parasite: an organism that lives in or on a host organism that…

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Global distribution: widely distributed across the tropics and subtropics

More than 1 million people die of malaria each year, mostly infants in Africa
Mosquitoes are resistant to insecticides
Plasmodium is drug resistant

Acquired immune deficiency syndrome is caused by human immodeficiency virus, which
infects T-cells by:

The virus injects viral…

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Natural Natural immunity by infection Advantage: Immediate
Advantage: long-term immunity protection
Disadvantage: disease may be Disadvantages: short-term, no
fatal memory cells
Example: antibodies passed from
mother to child across placenta,
foetal blood or breast milk
(exposed to lots of antigen
cycles)
Artificial Example: vaccination-actual antibodies and injected
antigens injected Advantages:…

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