Topic 1: Inorganic ions

Question 1

Where do inorganic ions occur?

Answer 1

• In solution in the cytoplasm
• In body fluids in the organisms

Question 2

Explain the importance of H+ ions.

Answer 2

-Concentration of H+ ions determines the pH.
High conc: Lower pH (acidic)
Low conc: Higher pH (alkaline)

-Important for enzyme-controlled reactions as they’re affected by changes in the pH.

Question 3

Explain how changes in the pH affect enzymes rate of reaction

Answer 3

Abnormal levels of H+ ions can interact with side-chains of amino acids and change the secondary and tertiary structure of the protein which causes the enzyme to denature. No more E-S complexes formed

Question 4

Explain the importance of Iron ions.

Answer 4

-It’s a component of the haem group in haemoglobins
-Allows oxygen to bind for transport as oxyhaemoglobin

Question 5

Explain the importance of Na+ ions.

Answer 5

-Required for the co-transport of glucose and amino acids into cells.
-Required for the transmission of nerve impulses

Question 6

Explain the importance of phosphate ions. (4 marks)

Answer 6

-Component of nucleotides, allowing phosphodiester bonds to form in DNA/RNA
-Component of ATP, allowing energy release
-Phosphorylates other compounds, making them more reactive.
-Hydrophilic part of the phospholipid, allowing a bilayer to form