2.2 Biological molecules

Question 1

Calcium ion

Answer 1

Ca2+

• Increases rigidity of bone. teeth and cartilage and is a component of the exoskeleton of crustaceans
• Important in clotting blood and muscle contraction
• Activator for several enzymes, such as lipase
• Stimulates muscle contraction and regulates transmission of nerve impulses
• Regulates permeability of cell membranes
• Important for cell wall development in plants, and formation of middle lamella between cell walls

Question 2

sodium ions

Answer 2

Na+
- Involved in regulation of osmotic pressure, control of water levels in body fluid and maintenance of PH
- Constituent of vacuole in plants which helps maintain turgidity
- affects absorption of carbohydrate in the intestine and water in kidney
- contributes to nervous transmission and muscle contraction

Question 3

Potassium ion

Answer 3

K+
- Involved in control of water levels in body fluid and maintenance of ph
- assists active transport of materials across the cell membrane
- involved with the synthesis of glycogen and protein and breakdown of glucose
- generates healthy leaves and flowers in flowering plants
- Contributes to nervous transmission and muscle contraction
- Component of vacuoles in plants. helping to maintain turgidity

Question 4

hydrogen ions

Answer 4

H+
- involved in photosynthesis and respiration
- involved in transport of oxygen and carbon dioxide in the blood
- involved in regulation of blood PH

Question 5

Ammonium ions

Answer 5

NH4 +
- a component of amino acids, proteins, vitamins and chlorophyll
- some hormones are made of proteins eg insulin
- an essential component of nucleus acids
- involved in maintenance of PH in the human body
- component of the nitrogen cycle

Question 6

nitrate ion

Answer 6

NO3 -
- component of amino acids, proteins, vitals and chlorophyll
- essential component of nucleic acids
- hormones are made of proteins which contain nitrogen eg insulin
- component of nitrogen cycle

Question 7

hydrogencarbonate ion

Answer 7

HCO3 -
- involved in regulation of blood PH
- involved in transport of carbon dioxide into and out of the blood

Question 8

chloride ion

Answer 8

Cl-
- helps in production of urine in the kidney and maintaining water balance
- involved in transport of carbon dioxide into and out of the blood
- regulates affinity or haemoglobin to oxygen through allosteric effects on the haemoglobin molecule
- involved in regulation of blood PH
- uses to produce hydrochloric acid in the stomach

Question 9

phosphate ions

Answer 9

PO4 3-
- increases rigidity of bone, teeth, cartilage and is a component in the exoskeleton in crustaceans
- component of phospholipids, ATP, nucleic acids and enzymes
- involved in regulation of blood PH
- helps root growth in plants

Question 10

hydroxide ion

Answer 10

OH-
- involved in regulation of blood PH