biological molecules PMT ans

Question 1

water is a solvent that allows…

Answer 1

metabolic reactions to occur

Question 2

water has a high SHC which…

Answer 2

minimises temperature fluctuations acting as a buffer.

Question 3

water in terms of latent heat of vaporisation

Answer 3

high latent heat = evaporation of water provides cooling effect

Question 4

water in terms of cohesion

Answer 4

strong cohesion supports columns of water + surface tension at the water-air boundary is high

Question 5

ice vs water

Answer 5

ice is less dense than water = floats on top creating an insulating layer.

Question 6

what is a condensation reaction

Answer 6

reaction which joins monomers by chemical bonds and involved the elimination of a water molecule

Question 7

what bonds hold polysaccharides together?

Answer 7

glycosidic bonds

Question 8

name 3 disaccharides

Answer 8

maltose
sucrose
lactose

Question 9

maltose =

Answer 9

disaccharide formed by condensation of two glucose molecules

Question 10

sucrose =

Answer 10

disaccharide formed by condensation of glucose + fructose

Question 11

lactose =

Answer 11

disaccharide formed by condensation of glucose + galactose

Question 12

glycogen and starch are formed by the condensation of…

Answer 12

alpha glucose joined together by 1,4 and 1,6 glycosidic bonds

Question 13

glycogen properties

Answer 13

large number of side branches meaning that glucose (energy) can be released quickly.
It is relatively large but compact thus maximising the amount of energy it can store.

Question 14

starch =

Answer 14

amylose and amylopectin

Question 15

amylose…

Answer 15

unbranched chain of glucose molecules joined by 1,4 glycosidic bonds, as a result of that amylose is coiled and thus is a very compact molecules meaning it cans store lots of energy.

Question 16

amylopectin…

Answer 16

is branches and is made up of glucose molecules joined by 1,4 and 1,6 glycosidic bonds, due to the presence of many side branches it is rapidly digested by enzymes and therefore energy is released quickly.

Question 17

what are microfibrils

Answer 17

strong threads which are made of long celluose chains joined together by hydrogen bonds which provide structural support in plant cells.

Question 18

saturated lipids? where are they found?

Answer 18

don’t contain any C-C double bonds, found in animal fat

Question 19

unsaturated lipids?

Answer 19

contain carbon=carbon double bonds, and melt at lower temps than saturated fats - found in plants + have a KINK

Question 20

the greater the number of unsaturated bonds…

Answer 20

the weaker the intermolecular bonds resulting in a lower melting point.

Question 21

hydrogen ions (function)

Answer 21

determine the pH of substance e.g. blood - the higher the concentration of Hydrogen, the lower the pH

Question 22

sodium ions function…

Answer 22

involved in co-transport of glucose and amino acids

Question 23

amino acids joined together by..

Answer 23

peptide bonds formed in condensation reactions

Question 24

difference between dipeptide and polypeptide

Answer 24

dipeptide = two amino acids
polypeptide = three or more amino acids

Question 25

globular proteins are..

Answer 25

compact

Question 26

function of collagen

Answer 26

wrap around each other and form fibrils which from strong collagen fibres. collagen forms the structure of bones, cartilage and connective tissue and is the main component of tendons which connect the muscles to bones.

Question 27

haemoglobin is a… (+ what kinds of polypeptide chains)

Answer 27

water soluble globular protein.

2 beta and 2 alpha pp chains