Food CH3

Question 1

Nutrition

Answer 1

The way in which an organism obtains and uses food.

Question 2

Nutrients

Answer 2

The substances in food that are used by organisms.

Question 3

What are nutrients necessary for

Answer 3

Growth and repair
energy
metabolic reactions

Question 4

How many elements are food mainly made of

Answer 4

14
Apart from hydrogen, carbon and oxygen, they are called minerals.

Question 5

6 Common elements

Answer 5

Carbon
Hydrogen
Oxygen
Nitrogen
Phosphorus
Sulfur

Question 6

Dissolved salts

Answer 6

Sodium
Magnesium
Chlorine
Pottassium
Calcium

Question 7

Trace elements

Answer 7

Iron
Copper
Zinc

Question 8

Biomolecules

Answer 8

Chemicals made inside a living thing

Question 9

4 biomolecules in food

Answer 9

Carbohydrates
Lipids
Proteins
Vitamins

Question 10

Elements in carbohydrates

Answer 10

Carbon,
Hydrogen
Oxygen

Question 11

Element ratio for carbohydrates

Answer 11

Cx(H2O)y

(twice as much hydrofen as oxygen or carbon)

Question 12

Types of carbohydrates

Answer 12

Monosaccharides
Disaccharides
Polysaccharides

Question 13

Monosaccharides

Answer 13

-Single sugar unit
-Smallest type of carbohydrate
-Sweet taste and soluble in water

Question 14

Examples of monosaccharides

Answer 14

Glucose - found in sweets, fruits and made by plants
Fructose - found in fruits

Question 15

Disaccharides

Answer 15

-Made of two sugar units joined together
-Sweet tasting and soluble in water

Question 16

Examples of disaccharides

Answer 16

Maltose - found in germinating seeds (2glucose molecules)
Sucrose - table sugar (a glucose joined to a fructose)

Question 17

Polysaccharides

Answer 17

-Made of many sugar units ( often thousands )
-Insoluble or slightly in water
-not sweet tasting

Question 18

Examples of polysaccharides

Answer 18

Starch
cellulose
glycogen

Question 19

Starch

Answer 19

-Made of many glucose molecules joined together
-Is the carb stored by plants
-easily digested as only two chemical bonds must be broken to release glucose

Question 20

Cellulose

Answer 20

-Made of many glucose molecules joined together by cross-bonding
-very strong
-difficult to digest

Question 21

Glycogen

Answer 21

-Made of large numbers of glucose arranged in branch chains
-Animals store glycogen in their livers and muscles.

Question 22

Sources of carbohydrates

Answer 22

Bread, pasta, rice, potatoes, sugars, fruits, sweets, cakes

Question 23

structural role of carbohydrates

Answer 23

Cellulose used to form plant cell walls

Question 24

Metabolic role of carbohydrates

Answer 24

Glucose broken down in respiration to release energy

glucose made in photosynthesis

Question 25

Lipids

Answer 25

Fats and oils

Question 26

Fats

Answer 26

Lipids solid at room temp

Question 27

oils

Answer 27

lipids liquid at room temo

Question 28

Elements of lipids

Answer 28

Carbon, hydrogen, oxygen

Question 29

Structure of lipids

Answer 29

1 molecule of glycerol linked to 3 fatty acid molecules (triglycerides)

Question 30

Phospholipids

Answer 30

fat-like substances, in which one of the fatty acids is replaced by a phosphate group or has a phosphate group added to it. Key component of cell membranes

Question 31

Source of lipids

Answer 31

Butter oils margarine cream fat on meats dried food

Question 32

Structural role of lipids

Answer 32

Heat insulation + protection of organs Energy stores in planta and animals Combine with phosphorus (phospholipids) and proteins (lipoproteins0 to form cell membrane.

Question 33

Metabolic role of lipids

Answer 33

Can be broken down in respiration to release energy

Question 34

Elements in proteins

Answer 34

carbon, hydrogen, oxygen nitrogen (sometimes small amts of sulfur, phosphorus and other elements.)

Question 35

Structure of proteins

Answer 35

-Composed of amino acids -amino acids are joined together by peptide bonds.

Question 36

How many types of amino acids are there

Question 37

peptide

Answer 37

less than 20 amino acids

Question 38

polypeptide

Answer 38

more than 20 amino acids

Question 39

protein folding

Answer 39

Determines how a protein will work - fibrous and globular

Question 40

Fibrous proteins

Answer 40

Little or no folding, are strong and tough eg keratin in hair nails and feathers.

Question 41

Globular proteins

Answer 41

Lots of folding and form rounded shapes eg. egg whites (albumin) enzymes

Question 42

What does incorrect protein folding cause

Answer 42

prions- eg BSE in cattle and CJD in humans

Question 43

Sources of proteins

Answer 43

Meat, fish, eggs, milk, nuts, peas, beans

Question 44

what happens to excess amino acids

Answer 44

Our body does not store amino acids. Excess amino acids are converted to urea in the liver in a process called deamination

Question 45

How is urea transported

Answer 45

Urea is carried in the blood to the kidneys and excreted in urine.

Question 46

Structural role of proteins

Answer 46

-Fibrous proteins eg keratin is found in skin and hair -Myosin found in muslces

Question 47

Metabolic role of proteins

Answer 47

-Used as enzymes to control reaction - Form antibodies to fight infection - Hormones regulate body reactions.

Question 48

Vitamin c

Answer 48

Water soluble vitamin

Question 49

Sources of vitamin c

Answer 49

veg, fresh fruit, limes, guava, peppers, grapefruit

Question 50

Metabolic role of vitamin c

Answer 50

- Forms connective tissue, bones and teeth, and is involved in wound healing and the immune system.

Question 51

Deficiency in vitamin c

Answer 51

Scurvy - bleeding gums, loose teeth, poor skin healing, bleeding under the skin

Question 52

Vitamin d

Answer 52

Fat soluble vitamin

Question 53

Sources vitamin d

Answer 53

Fish oils, liver, milk, egg yolk, made when uv light shines on skin

Question 54

Metabolic role of vitamin d

Answer 54

- Helps absorb calcium from intestine - Needed for healthy bones and teeth

Question 55

Deficiency in vitamin d

Answer 55

Rickets / osteomalacia - weak deformed bones that break easily

Question 56

Name two minerals plants need, why and where they get it

Answer 56

magnesium- salts in the soil, helps form chlorophyll calcium - salts in the soil, holds cell walls together

Question 57

Name two minerals animals need, why and where they get it

Answer 57

Iron- liver, meat, green veg, helps form haemoglobin Calcium- milk, cheese Dairy, Helps form bones and teeth

Question 58

5 reasons why water is important

Answer 58

1. Component of cytoplasm, tissue fluid and blood plasma 2. good slovent, allows chemical reactions to take place and transports materials. 3. Participates in chemical reactions 4.Moves in and out of cells to give them the correct shape 5. A good absorber of heat, provides a stable temperature for living things and their reactions

Question 59

Anabolic reaction

Answer 59

Uses energy to convert smaller molecules to larger molecules eg. formation of muscle from amino acids photosynthesis - cellulose made from co2 and glucose

Question 60

Catabolic reactions

Answer 60

Releases energy whe a larger molecule is broken down into smaller ones