2.4 Inorganic ions

Question 1

What is an inorganic ion

Answer 1

An inorganic ion is one which doesn’t contain carbon (although there are
a few exceptions to this rule).
There are inorganic ions, in solution, in the cytoplasm of cells and in the body fluids of organisms.
Inorganic ions perform a range of functions.
The specific function a particular ion performs is related to its properties.
An ion’s role determines whether it is found in high or low concentrations.

Question 2

Describe the role of hydrogen ions

Enzyme related

Answer 2

• Maintains pH levels in the body-High conc=Acidic/Low pH
• Affects enzyme rate of reaction as can cause enzymes to dentaure

Question 3

Describe the role of Iron ions (Fe3+)

Haemoglobin

Answer 3

• Component of Haem group of haemoglobin
• Allowing oxygen to bind for transport as oxyhaemoglobin

Question 4

Describe the role of Sodium ions (3)

Answer 4

1. Involved in co transport of glucose/amino acids into cells
2. Involved in action potentials in neurons
3. Affects water potential of cells/osmosis

Question 5

Describe the role of Phosphate ions (4)

PO4-3

Answer 5

1. Component of nucelotides, allowing phosphodiester bonds to form in DNA/RNA
2. Component of ATP, allowing energy release
3. Phosphorylates other compounds making them more reactive
4. Hydrophilic part of phospholipids, allowing a bilayer to form

Question 6

Exam insight:COmmon mistakes

Answer 6

Naming an ion as an element - DOnt just say ‘Iron’ when referring to Iron ions
ATP hydrolysis creates energy- Energy can only be transferred/ released