Food - Leaving Cert

Question 1

Biomolecule

Answer 1

Organic chemical produced and found only within living organisms

Question 2

Metabolism

Answer 2

The sum of all chemical reactions in an organism

Question 3

Types of metabolism

Answer 3

Anabolic

Catabolic

Question 4

Anabolic

Answer 4

Energy is required to convert smaller molecules into larger molecules
eg photosynthesis, protein synthesis

Question 5

Catabolic

Answer 5

Energy released to convert larger molecules into smaller molecules
eh respiration, digestion

Question 6

Why do we need food

Answer 6

Energy source for respiration

Growth and repair of cells

Question 7

Chemical elements found in food

Answer 7

C, H , O , N , P , S
Salts of:
Na, Mg, Cl, K, Ca
Traces of:
Fe, Cu, Zn

Question 8

Biomolecule types

Answer 8

Carbs
Lipids
Proteins
Vitamins

Question 9

Carbohydrates general formula and ratio

Answer 9

Cx(H2O)y

X=Y Y=6
Ratio: 2:1 (2hydrogen 1oxygen)

Question 10

Carbohydrates structural role

Answer 10

Cellulose(poly) found in plant cell walls

Chitin(poly) found in fungal cell walls

Question 11

Carbohydrates metabolic role

Answer 11

Glucose(mono) broken down to release energy in respiration
Glucose stored as glycogen in animal muscle after respiration
Starch (poly) stores glucose after photosynthesis

Question 12

Monosaccharide

Answer 12

1 single sugar unit
eg glucose, fructose

Source- fruit

Question 13

Disaccharide

Answer 13

Two sugar molecules joined
eg sucrose, lactose, maltose

Source- table sugar, milk

Question 14

Polysaccharide

Answer 14

Many sugar molecules joined
eg starch, cellulose

Source- bread, pasta, cereal

Question 15

Lipids types

Answer 15

Triglycerides (3 fatty acids one glycerol)

Phospholipids (one fatty acid replaced by a phosphate group) (major component of cell membranes)

Question 16

Lipids general structural components

Answer 16

Fatty acids and glycerol

Question 17

Examples of lipids

Answer 17

Fats- solid at room temp
Oils- liquid at room temp
Steroids (cholesterol and some sex hormones)

Question 18

Structural role of lipids

Answer 18

In cells: phospholipids are major component of cell membranes
In an organism: energy store, protection of organs, heat insulation

Question 19

Metabolic role of lipids

Answer 19

Release energy in respiration

Question 20

Protein shapes

Answer 20

Fibrous - no folding eg keratin in hair and nails

Globular - lots of folding eg albumin in egg white, enzymes

Question 21

Structural role of proteins

Answer 21

Keratin in skin and hair

Myosin in muscles

Question 22

Metabolic role of proteins

Answer 22

All enzymes are proteins -> biological catalysts that control photosynthesis and respiration
Hormones regulate body functions eg insulin regulates blood sugar levels

Question 23

Vitamins

Answer 23

Needed in small amounts

Cannot be made by the body

Question 24

Vitamin C

Answer 24

Water soluble 
Chemical name: ascorbic acid
source: citrus fruits,green veg
deficiency: scurvy
symptoms: soft bleeding gums

Question 25

Vitamin C functions

Answer 25

Build connective tissue
Maintain bones and teeth
Good immune system function

Question 26

Vitamin D

Answer 26

Fat soluble
Chemical name: calciferol
Source: dairy, fish liver oils, egg yolk
Deficiency: tickets in children, osteomalacia in adults
Symptoms: bones lose calcium and break easily

Question 27

Vitamin D Functions

Answer 27

Needed to absorb calcium from food

To form bone

Question 28

Minerals

Answer 28

Inorganic
Needed in small amounts
Plants absorb minerals through their roots
Animals get minerals through food

Question 29

Plant minerals

Answer 29

Calcium - to form middle lamella (cell wall) between cells

Magnesium - to form part of chlorophyll

Question 30

Animal minerals

Answer 30

Calcium- forms bones and teeth

Iron- forms part of haemoglobin

Question 31

Water

Answer 31

Cells and body fluid are made of 70% water in animals and 90% in plants

Question 32

Uses of water

Answer 32

Universal solvent that transports substances in blood or in plants, allows substances to move through membranes
Where all metabolic reactions take place, component of cytoplasm, controls shape of cell by osmosis
Is a reactant/product in chemical reactions, source of oxygen produced in photosynthesis