Acids, Bases and Buffers

Question 1

What is an acid

Answer 1

a molecule/ ion that tends to give up protons in solution

Question 2

What is a base

Answer 2

a molecule/ ion that tends to acquire proteins in solution

Question 3

Ka

Answer 3

acid dissociation constant , measures the strength of acid in solution

Question 4

pKa

Answer 4

negative log of Ka

indicates strength of acid, Lower the pKa the stronger the acid

Question 5

carbonic acid in the body

Answer 5

formed when CO2 combines with water in the blood

acts as a buffer

Question 6

lactic acid in the body

Answer 6

secreted during anaerobic respiration and can cause cramp

Question 7

hydrochloric acid in the body

Answer 7

secreted into the stomach as part of the digestive process

Question 8

name some acids produced by oral bacteria under anaerobic conditions

Answer 8

lactic acid, formic acid, acetic acid, propionic acid, butyric acid

Question 9

what causes dental caries

Answer 9

acids produced by oral bacteria

Question 10

what causes tooth erosion

Answer 10

acids in the diet e.g fizzy drinks, fruit juices

Question 11

what effects do acids have on hydroxyapatite

Answer 11

causes hydroxyapatite to to become more soluble

Question 12

how are the negative effects of acids on hydroxyapatite reversed

Answer 12

calcium containing foods e.g milk and saliva (which contains calcium and phosphate) inhibit solubilisation and promote remineralisation

Question 13

chelating agents and their oral effect

Answer 13

chelating agents bind with metal ions e.g calcium stopping it counteracting calcium solubilisation

Question 14

what is an example of a chelating agent

Answer 14

citric acid which is found in fruit juices

Question 15

what is the main buffer in saliva

Answer 15

bicarbonate

Question 16

what are examples of buffers in saliva

Answer 16

bicarbonate, phosphate, proteins