12drevision-ansbio
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Transcript of 12drevision-ansbio
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(c) %& Protein binds to / blocks / competes with substrate for! active site;
2& Prevents substrate from binding / prevents formation of
en=*me:substrate comple$ / e";
& Protein binds to point other than the active site of the en=*me /
reference to allosteric;
& Changes shape of active site; [8]
3. (a) # 'att* acid / h*drophobic region / tail! / phospholipid tail
0 Phosphate / gl*cerol / h*drophilic region / head! / phospholipid head
C (Channel / transmembrane / intrinsic) protein
1 7l*coprotein 2
[Half mark each, rounded down]
(b) Facilitated diffusion
-hrough channel / carrier! protein;
1own a concentration gradient / e";
Active transport
sing carrier protein;
8nerg* from #-P;
#gainst concentration gradient;
Exocytosis / endocytosis
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(ii) %& Membrane selectivel* permeable at lower temperatures;
2& -emperature increase above A BC / higher temperatures!
/ membrane breaks down / e";
& 5ncrease of kinetic energ* of pigment
molecules / phospholipids in membrane / e"!;
& Proteins are denatured;
+& Membrane becomes freel* / more! permeable to
(pigment molecules) with increasing temperature;
>& .eference to diffusion of pigment molecules out of the
cells / reaches e"uilibrium at high temperatures; [12]
4. (a) %& .eference to thin wall;
2& Single cell la*er / reference to s"uamous epithelium;
& 1ecreases diffusion distance;
& .eference to surfactants prevent alveolar collapse / cells
sticking together!;
+& .eference to network / e"! of capillaries;
>& .eference to maintenance of diffusion gradient;
(b) (i) %& #lveolar air has had o$*gen removed;
2& 8$pired air is mi$ture of (inspired) air / air in tubes!and alveolar air; 2
(ii) %& #ir (in alveoli) ventilated / replenished fre"uentl*! / e";
2& 5dea of blood flowing through the capillaries;
& .eference to o$*gen / o$*genated blood! being carried awa* /
allow converse for carbon dio$ide; 2
Barking Abbey School 3
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(c) %& Smokers babies have lower birth weight / fetus has low growth rate!;
2& 0ab* ma* have poorer lung / e"! function;
& .eference to poor brain development / function!;
& .educed o$*gen suppl* to fetus as carbon mono$ide (in smoke)
replaces o$*gen;
+& Smoking interferes with mothers uptake of vitamin 0 / C / folic acid!;
>& 5ncreased risk of placental complications e&g& placental abruption / e";
?& 5ncreased risk of still birth / premature birth / miscarriage / e"!;
@& .eference to nicotine interfering with fetal development;
D& .eference to bab* having nicotine addiction;
(d) %& 5ncreased death rate / e"! in older people / e";
2& 5ncreased death rate / e"! in middle:aged people / A:>A *ear olds!;
& .eference to cancer / emph*sema / bronchitis / circulator* disorders / e"!;
& 1ecreased birth rate / fewer children;
+& 1ecreased fertilit* / failed pregnanc* / e"! / childhood disease; 2[12]
5. (a) W E coronar* arteries
X E aorta
Y E (left) pulmonar* arter*
Z E pulmonar* vein
correct E 2 marks
2 or correct E % mark
A or % correct E A marks 2
(b) #ward one mark for each of the following points in
conte$t to a ma$imum of four&
%& ventricle (muscle) contracts;
2& higher pressure in ventricles relative to atria;
& (pressure) closes atrioventricular valve;
& higher pressure in ventricles relative to the aorta /
pulmonar* arter* / arteries!;
+& (pressure) opens the semilunar valve;
>& blood forced into the aorta / pulmonar* arter* /
arteries!; Ma$
Barking Abbey School 4
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(c) #ward one mark for each of the following points in conte$t to
a ma$imum of three&
%& place#aphnia on cavit* slide / e"! with caffeine;
2& (focus on heart) using microscope;
& ref& to range of caffeine concentrations;
& ref& to repeats;
+& ref& to water as control / =ero caffeine concentration!; Ma$
#ward one mark for each of the following points in conte$t to
a ma$imum of three&
%& control temperature;
2& reference to similar organisms used;
& accurate measurement of 1