Inorganic ions

Question 1

Doctors investigated the link between high sodium concentrations in medicines
and hypertension (high blood pressure).
They analysed medical records of patients. 1 292 337 of these patients had taken
medicines containing high sodium concentrations. Each of these patients was
paired with a patient from a control group.
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(b) Give two factors that should have been the same for each pair of patients
and one factor that should have been different.

Answer 1

Same
Accept any two of the following for one mark
1. BMI, age, sex/gender, other/previous medications, ethnicity, diet,
exercise, health (issues)
Ignore weight
Different
2. No sodium in the (same) medicine;

Question 2

(a) Describe the roles of iron ions, sodium ions, and phosphate ions in cells.

Answer 2

Iron ions
1. Haemoglobin binds/associates with oxygen

Haemoglobin transports/loads oxygen;

Sodium ions
2. Co-transport of glucose/amino acids (into cells);

3. (Because) sodium moved out by active transport/Na – K pump;
4. Creates a sodium concentration/diffusion gradient;
5. Affects osmosis/water potential;

Phosphate ions

6. Affects osmosis/water potential;
7. Joins nucleotides/in phosphodiester bond/in backbone of
   DNA/RNA/in nucleotides;
8. Used in/to produce ATP;
   Reject ‘energy produced’
9. Phosphorylates other compounds (usually) making them more
   reactive;
10. Hydrophilic/water soluble part of phospholipid bilayer/membrane

Question 3

A high concentration of sodium in the blood can affect blood volume and
cause hypertension.
Use your knowledge of water potential to suggest how high sodium
concentrations in the medicines taken could affect blood volume.

Answer 3

(Sodium ions) lower the water potential (of blood);
Accept make the blood water potential more
negative
Accept decrease the blood water potential
2. Water would move into the blood by osmosis (from cells/tissue fluid);
3. Increasing the blood volume;