Respiration, Diet and Biological Molecules

Question 1

Write a word equation for aerobic respiration

Answer 1

Glucose + oxygen –> carbon dioxide + water

Question 2

Write a balanced chemical equation for aerobic respiration

Answer 2

C6H12O6 + 6O2 –> 6CO2 + 6H2O

Question 3

Write a word equation for anaerobic respiration in mammals

Answer 3

Glucose —> lactic acid

Question 4

Write a word equation for anaerobic respiration in plants and fungi

Answer 4

Glucose –> Ethanol + carbon dioxide

Question 5

What is the role of ATP in respiration?

Answer 5

It is produced to provide energy for cells

Question 6

Compare the ATP produced in both aerobic and anaerobic respiration

Answer 6

More ATP produced in aerobic than in anaerobic respiration

Question 7

Aside from chemical energy (ATP), in what other form is energy lost in respiration

Answer 7

Heat energy

Question 8

Identify the chemical elements present in carbohydrates, proteins and lipids

Answer 8

Carbohydrates and Lipids both contain carbon, hydrogen and oxygen; proteins contain nitrogen in addition to C, H and O

Question 9

Give five examples of carbohydrate molecules

Answer 9

Glucose, starch, sucrose, cellulose, glycogen etc.

Question 10

State the basic subunits of proteins

Answer 10

Amino acids

Question 11

State the basic subunits of lipids

Answer 11

Fatty acids and glycerol

Question 12

State the chemical used to test for starch and give the positive result

Answer 12

Iodine; turns brown –> blue-black

Question 13

State the chemical used to test for protein and give the positive result

Answer 13

Biuret; turns blue –> purple

Question 14

Describe the chemical test for lipids and give the positive result

Answer 14

Dissolve sample in ethanol and add cold water; lipids present if a cloudy, white emulsion appears

Question 15

Describe the chemical test for glucose and give the positive result

Answer 15

Add Benedict’s solution to sample and HEAT in a boiling water bath; if glucose present, turns blue –> brick red (green, orange intermediate colours)

Question 16

Define the term balanced diet

Answer 16

Appropriate proportions of carbohydrate, proteins, lipids, vitamins, minerals, water and dietary fibre

Question 17

Give two examples (for each nutrient) of foods high in carbohydrate, protein and lipid

Answer 17

Carbohydrates: pasta, rice, potato etc.; Proteins: meat, fish etc.; Lipids: butter, cheese, milk, oils etc.

Question 18

Describe the functions of carbohydrates, proteins and lipids

Answer 18

Carbohydrates: respired to release energy; proteins: used in growth and repair; lipids: insulation and as a high energy source

Question 19

State a source of each of vitamins A, C and D

Answer 19

Vit A: carrots, sweet potato; Vit C: citrus fruits; Vit D: sunlight, fish, liver

Question 20

Suggest a consequence of low fibre in the diet

Answer 20

Constipation

Question 21

Suggest a consequence of low vitamin C in the diet

Answer 21

Scurvy

Question 22

Suggest a consequence of low iron in the diet

Answer 22

Anaemia

Question 23

Suggest a consequence of low calcium in the diet

Answer 23

Poor bone and teeth development

Question 24

State two sources of iron in the diet

Answer 24

Red meat, spinach.

Question 25

State three factors that affect energy requirements of individuals

Answer 25

Age, pregnancy, activity levels