Topic 1, biological molectles

Question 1

colloids/ colloidal suspension

Answer 1

Molecules with strong intra molecular forces e.g proteins, but charged areas on surface. Attracts layer of water on surface so molecules remain dispersed.

Question 2

importance of colloids/ colloidal suspension?

Answer 2

water molecules are weakly bonded to the molecule’s surface and cant leave its surface, helpful for the osmotic effect it creates

Question 3

after how many 1-4 bonded molecules is there a branch (1-6) in amylopectin

Answer 3

25

Question 4

Why is cellulose an excellent structural polysaccharide

Answer 4

The H bonds in the microfibrils make it resistant to water and enzyme hydrolysis

Question 5

why is chitin stronger than cellulose

Answer 5

It is made of glucosamine. the presence of amino acids increases the H bonds

Question 6

monounsaturated fatty acid

Answer 6

only one double carbon bond

Question 7

polyunsaturated fatty acid

Answer 7

more than one carbon double bonds

Question 8

trans fat?

Answer 8

H are bonded either side of the acid around the double carbon bond

Question 9

sis fat?

Answer 9

H bonded to one side of the fatty acid around the carbon double bond

Question 10

where are saturated fats and unsaturated found?

Answer 10

Saturated=animal fats, unsaturated=plant fats

Question 11

LDL

Answer 11

Low Density Lipoprotein: transporting molecules, produced in the liver, increase incidence of atheromas in arteries, cause blockages, no O or C6H12O6 to heart

Question 12

HDL

Answer 12

High Density Lipoproteins, remove cholesterol deposits “good”

Question 13

Micelle?

Answer 13

Phospholipids form a droplet sphere with tails inwards and heard outwards when mixed with water

Question 14

phospholipid bilayer

Answer 14

ring made of 2 layers of fatty acids trapping a compartment of water in the centre. Structure= liposome

Question 15

Triose example

Answer 15

Glyceralderhyde

Question 16

pentose example

Answer 16

ribose/ deoxyribose

Question 17

Amino FG

Answer 17

Water soluble, acts as a weak base (accepts H+)

Question 18

Carboxyl FG?

Answer 18

Water soluble, lightly polar, acts as an acid

Question 19

Phosphate FG

Answer 19

water soluble, acidic

Question 20

disease caused by atheromas

Answer 20

atherosclerosis

Question 21

amphipathic?

Answer 21

a molecule with both hydrophobic and hydrophilic parts

Question 22

How many essential amino acids

Answer 22

8- they cannot be made by the body

Question 23

Alpha bonds?

Answer 23

Points in the opposite direction of the oxygen linkage(down) Formed when the first saccharide is alpha

Question 24

beta bonds?

Answer 24

Points in the same direction as the oxygen linkage (up) Formed when the first saccharide is beta

Question 25

liquid triglycerides?

Answer 25

Unsaturated: kinks in tail at carbon to carbon double bond, cant pack closely, weaker forces of attraction Shorter tail: weaker forces of attraction, less energy to break

Question 26

solid triglycerides?

Answer 26

Saturated: straight tails, pack closely, stronger forces of attraction Longer tails: stronger forces of attraction

Question 27

most fluid cell membranes?

Answer 27

only unsaturated fats

Question 28

least fluid cell membranes?

Answer 28

only saturated fats

Question 29

use of Mg2+ in plants and animals?

Answer 29

Component of chlorophyll, used for photosynthesis Component in bones in animals

Question 30

Uses of iron ions in animals?

Answer 30

Component of haemoglobin, transports oxygen in red blood cells Lack of iron leads to anaemia

Question 31

Uses of PO4^3- in animals and plants?

Answer 31

Making nucleotides, component of phospholipids found in plasma membrane

Question 32

Uses of calcium in plants and animals?

Answer 32

Is a component of cell wall in plants, providing strength Is a structural component of bones and teeth in animals

Question 33

cohesion?

Answer 33

The attraction of water molecules for each other because of the polar structure, producing H bonds between molecules

Question 34

waters max density?

Answer 34

4 degree Celsius

Question 35

Where?: Maltose, sucrose, lactose

Answer 35

In germinating seeds, transported through the phloem of flowering plants, in mammals' milk

Question 36

Reducing sugars?

Answer 36

Sugars that can donate an electron: monosaccharides+ maltose

Question 37

Cellulose in relation to the cell wall?

Answer 37

Cellulose microfibrils are held in bundles called fibres, fibres run parallel within a layer but at an angle to adjacent layers in the cell wall. = strong and permeable

Question 38

what is chitin made of

Answer 38

heteropolysaccharides

Question 39

waxes?

Answer 39

lipids and melt over 45°c, have a waterproofing role e.g waxy cuticle and insect exoskeleton

Question 40

zwitterion?

Answer 40

amino acid at pH 7 since it has both a pos and neg charge

Question 41

Condensation reaction?

Answer 41

Joining two molecules creating a chemical bond and removing a water molecule

Question 42

Hydrolysis reaction?

Answer 42

Breaks a chemical bond between two molecules involving chemical addition of water

Question 43

Key properties of water

Answer 43

Metabolite, universal solvent, high SHC, hight LHV, strong cohesion