Biology · Oct / Nov 2021 · Paper 42 · Question 1

duodenum ;

any three from:

ref. to membrane for active transport ;

uses (chemical) energy ;

energy from, the cell / respiration / mitochondria ;

(substances move) against concentration gradient / low to high concentration ; using / AW, proteins / carriers (in membranes) ;

idea of more (cell) membrane / large surface (area) ;

allow, increased rate of / fast, absorption (of nutrients) ;

mucus ;

any two from:

(to protect the intestine from)

bacteria / viruses / microorganisms / parasites / pathogens ;

(named) toxin(s) ;

(named) enzymes / prevents self digestion ;

(hydrochloric) acid / alkali / base / extreme pH ;

physical damage by food passing through intestine / AW ;

absorbs, fats / fatty acids (and glycerol) ;

transports, fats / fatty acids, into, lymph(atic) vessels / lymph(atic)

system / lymph ;

organ ;

cell structure ;

tissue ;

organ ;

conclusions

1

fungal extract contains amylase and pectinase ;

2

clear zone is where substrate has been, digested / broken down ; 3

extract has a higher concentration than 1% of amylase ;

4

extract has lower concentration than 1% of pectinase ;

5

extract has, higher concentration of / more, amylase than pectinase ; evidence - can refer to what is in the wells (A to D)

6

D / fungal extract, in both Petri dishes has clear zones (MP1) ;

7

no staining in clear zones shows that enzyme was active (MP2) ; 8

size of clear zone, D / with fungal extract, is bigger than A / amylase solution (MP3) ;

9

size of clear zone, D / with fungal extract, is smaller than B / pectinase solution (MP4) ;

10 clear zone in, D / with fungal extract, is larger in the plate containing starch than in the plate containing pectin (MP5) ;

11 enzymes, diffuse / move, through the agar ;

12 greater the clear area the greater, the activity / concentration, of the enzyme ;

13 no clearance / no breakdown / no change, with water ;

(same pattern but) smaller / no, clear zones ;