Biologyical Molecules

Question 1

Monomer

Answer 1

Small units from which larger molecules are made

Question 2

Polymer

Answer 2

Molecules made from large numbers of monomers joined together

Question 3

Monosaccharides

Answer 3

Monomers from which larger carbohydrates are made. Glucose, galactose and fructose.

Question 4

Condensation reaction

Answer 4

Two molecules join together creating a glycosidic bond. Water molecule is formed- eliminated out of molecules

Question 5

Hydrolysis reaction

Answer 5

A molecule of water is added to break the chemical bond between the molecules

Question 6

How are disaccharides formed?

Answer 6

By condensation of two monosaccharides.

Question 7

Disaccharide maltose

Answer 7

Two glucose molecules

Question 8

Disaccharide sucrose

Answer 8

Glucose and fructose molecule

Question 9

Disaccharide lactose

Answer 9

Glucose and galactose molecule

Question 10

Isomers of glucose

Answer 10

ALPHA- glucose and BETA- glucose

Question 11

How are polysaccharides formed?

Answer 11

Condensation of many glucose units

Question 12

Amylose in plant cells

Answer 12

Release glucose for respiration.
Breaks up starch into maltose.
Energy store.

Question 13

Glycogen I’m animal cells

Answer 13

Broken down into glucose which is released into bloodstream to be used as fuel for cell.
Energy store.

Question 14

Cellulose in plant cells

Answer 14

Holds cell together.
Provides strength.
Provides rigidity.

Question 15

Properties of starch and glucose

Answer 15

Compact.
Easily hydrolysed.
No osmotic effect.
Insoluble.

Question 16

Properties of cellulose

Answer 16

Insoluble.
High tensile strength.
Flexible.
Strong cell walls.

Question 17

Reducing sugars test

Answer 17

Benedict’s:
Add 3cm^3 of sugar solution to 5cm^3 of Benedict’s in a test tube.
Heat(boiling water in hot water bath. 5 minutes.
Observe colour change: low- blue/green. Medium- orange. High- brick red.

Question 18

Reducing sugar

Answer 18

Glucose
Galactose
Fructose
Maltose
Lactose

Question 19

Test for non-reducing sugar

Answer 19

Boil acid (HCL) to hydroxide the covalent bond. Then neutralise (with sodium hydrogrencarbonate). Then boil with Benedict’s.

Question 20

Non-reducing sugars

Answer 20

Sucrose

Question 21

Triglycerides

Answer 21

Group of lipid
Important energy store in animals and plants.
One glycerol molecule and 3 fatty acids, joined by a condensation reaction

Question 22

Phospholipid

Answer 22

One phosphate, one glycerol and 2 fatty acids.
Form a bilateral naturally: hydrophilic head, hydrophobic tails.
All biological membranes are made up of a phospholipid bilayer.

Question 23

Functions of lipids

Answer 23

Waterproofing (insoluble, waxy cuticle)
Energy store (more energy per unit gram than any other food molecule type.)
Thermal insulation (adipose tissue- cushioning organs)
Membrane structure (made of phospholipid)
Electrical insulation (nerve fibres surrounded by fatty myelin sheath)
Steroid hormones (made from cholesterol)

Question 24

How is the ester bond formed

Answer 24

Condensation reaction between glycerol and fatty acid

Question 25

Fatty acids

Answer 25

Long hydrocarbon chains.
With a carboxylic acid group.
R-group maybe saturated or unsaturated.

Question 26

Saturated fatty acid

Answer 26

NO carbon double bonds.
E.g. triglycerides (straight)

Question 27

Unsaturated fatty acids

Answer 27

HAVE double carbon bonds
Monosaturated: one
Polusaturated: more than one
Double bonds = kinks

Question 28

Emulsion test for fats

Answer 28

Dissolve sample in water.
Pour alcohol in water (ethanol) n
OUTCOMES:
P: cloudy
N- water stays clear

Question 29

Alpha and beta glucose

Answer 29

CH2OH
ALPHA: OH is on bottom of Carbon 4 bond
BETA: OH is on top of carbon 4 bond