section 2: biological molecules - topic 6: inorganic ions

Question 1

what is an ion?

Answer 1

an atom (or group of atoms) that has an electrical charge.

Question 2

what is an inorganic ion?

Answer 2

an ion that doesn’t contain carbon.
(though there are a few exceptions)

Question 3

what is an ion with a positive charge called?

Answer 3

a cation.

Question 4

what is an ion with a negative charge called?

Answer 4

an anion.

Question 5

what are the 5 cations we need to know?

Answer 5

calcium.
sodium.
potassium.
hydrogen.
ammonium.

Question 6

what is the chemical symbol of calcium?

Answer 6

Ca^2+

Question 7

what is the chemical symbol of sodium?

Answer 7

Na+

Question 8

what is the chemical symbol of potassium?

Answer 8

K+

Question 9

what is the chemical symbol of hydrogen?

Answer 9

H+

Question 10

what is the chemical symbol of ammonium?

Answer 10

NH4+

Question 11

examples of calciums roles in biological processes.

Answer 11

• involved in the transmission of nerve impulses and the release of insulin from the pancreas.
• acts as a cofactor for many enzymes i.e. those involved in blood clotting.
• is important for bone formation.

Question 12

examples of sodiums roles in biological processes.

Answer 12

• important for generating nerve impulses, for muscle contraction, and for regulating fluid balance in the body.

Question 13

examples of potassiums roles in biological processes.

Answer 13

• important for generating nerve impulses, for muscle contraction, and for regulating fluid balance in the body.
• activates essential enzymes needed for photosynthesis in plant cells.

Question 14

examples of hydrogens roles in biological processes.

Answer 14

• affects the pH of substances (more H+ ions than OH- ions in a solution creates an acid).
• also important for photosynthesis reactions that occur in the thylakoid membranes inside chloroplasts and respiration reactions that occur in the inner membrane of mitochondria.

Question 15

examples of ammoniums roles in biological processes.

Answer 15

• absorbed from the soil by plants and is an important source of nitrogen (which is then used to make amino acids, nucleic acids etc).

Question 16

what are the 5 anions we need to know?

Answer 16

nitrate.
hydrogencarbonate.
chloride.
phosphate.
hydroxide.

Question 17

what is the chemical symbol of nitrate?

Answer 17

NO3-

Question 18

what is the chemical symbol of hydrogencarbonate?

Answer 18

HCO3-

Question 19

what is the chemical symbol of chloride?

Answer 19

Cl-

Question 20

what is the chemical symbol of phosphate?

Answer 20

PO4^3-

Question 21

what is the chemical symbol of hydroxide?

Answer 21

OH-

Question 22

examples of nitrates roles in biological processes.

Answer 22

• absorbed from the soil by plants and is an important source of nitrogen (which is then used to make amino acids, nucleic acids etc).

Question 23

examples of hydrogencarbonates roles in biological processes.

Answer 23

• acts as a buffer, which helps to maintain the pH of the blood.

Question 24

examples of chlorides roles in biological processes.

Answer 24

• involved in the ‘chloride shift’ which helps to maintain the pH of the blood during gas exchange.
• acts as a cofactor for the enzyme amylase.
• also involved in some nerve impulses.

Question 25

examples of phosphates roles in biological processes.

Answer 25

• involved in photosynthesis and respiration reactions.
• needed for the synthesis of many biological molecules i.e. nucleotides (including ATP), phospholipids & calcium phosphate (strengthens bones).

Question 26

examples of hydroxides roles in biological processes.

Answer 26

• affects the pH of substances (more OH- ions than H+ ons in a solution create an alkali).