Molecules

Question 1

Amylose

Answer 1

• Carb
• Polysaccharide
• a-glucose
• 1,4 glycosidic bonds
• Coiled
• Unbranched
• Energy storage in plants
• Insoluble
• Reacts w iodine to turn starch black

Question 2

Amylopectin

Answer 2

• Carb
• Polysaccharide
• a-glucose
• 1,4 glycosidic bonds
• Branched
• Branches form 1,6 glycosidic bonds
• Energy storage in plants
• Insoluble
• Branches can be hydrolysed to release a-glucose (for aerobic resp.)
• Less branched than glycogen

Question 3

Glycogen

Answer 3

• Carb
• Polysaccharide
• a-glucose
• 1,4 glycosidic bonds
• v branched
• Branches form 1,6 glycosidic bonds
• More compact than starch
• Energy storage in animals
• Insoluble
• Branches can b hydrolysed to release a-glucose (for aerobic resp.)
• More branched than amylopectin- more ends for hydrolysis - more energy released

Question 4

Cellulose

Answer 4

• Carb
• Polysaccharide
• ß-glucose
• 1,4 glycosidic bonds
• Every other ß-glucose flipped 180°
• Long
• Unbranched
• Microfibrils = chains cross-linked w H bonds
• Structural in plants e.g. cell walls
• Insoluble
• v strong
• Embedded in pectin
• Criss-cross inc. strength
• Allows plant cells to become turgid

Question 5

Haemoglobin

Answer 5

• Globular protein
• Quat. structure - 2 a chains and 2 ß chains
• Prosthetic haem group
• Fe2+ ion
• Carries oxygen
• Soluble

Question 6

Collagen

Answer 6

• Fibrous protein
• In chains, every 3rd amino acid is glycine
• Collagen molecule = 3 chains tightly interwoven - H bonds give extra strength
• Collagen fibrils = collagen molecules cross-linked w covalent bonds
• Structural in animals e.g. arterial walls, cartilage, tendons and connective tissue
• Insoluble
• High tensile strength
• NOT elastic
• Flexible

Question 7

Triglycerides

Answer 7

• Lipid
• 3 fatty acids + glycerol (ester bonds)
• Energy store in animals
• Insoluble
• Stored in adipose cells
• Can be broken down more completely than carbs to release more energy

Question 8

Phospholipids

Answer 8

• Lipids
• 2 fatty acid tails (ester bonds) + phosphate head group + glycerol
• Soluble head
• Insoluble tails
• More unsaturated tails = inc. fluidity

Question 9

Cholesterol

Answer 9

• 4 carbon ring structure
• Steroid hormones
• Regulates fluidity of CCM
• Insoluble
• Can cause atherosclerosis (by deposition in blood vessels) - narrows blood vessels, inc. blood pressure and risk of myocardial infarction