AQA A LEVEL BIOLOGY - PAPER 3 (SYNOPTIC)
QUESTIONS WITH ACTUAL ANSWERS .
What,are,the,useful,properties,of,water,and,why,?,,,ANS,-1),Water,is,a,metabolite,-
,in,many,metabolic,reactions,including,condensation,and,hydrolysis,
2),Water,is,a,solvent,-
,medium,in,which,enzyme,catalysed,reactions,take,place,(metabolic,reactions,),and,readily,dissolves,subst
ances,like,inorganic,ions,(,as,water,is,dipolar,so,totally,surrounds,the,ions),,,excretory,products,(urea/am
monia),,,respiratory,gases,and,small,hydrophilic,molecules,(,amino,acids,,,etc)
3),Water,has,a,high,latent,heat,of,vaporisation,(lots,of,energy,required,to,break,hydrogen,bonds,between,
water,molecules,so,a,lot,of,energy,is,used,up,when,water,evaporates,),so,helps,with,temperature,control,
as,evaporation,of,sweat,cools,humans,down,
4),Water,has,a,high,specific,heat,capacity,(,to,separate,the,many,hydrogen,bonds,requires,a,lot,of,energy),
so,acts,as,a,buffer,and,resists,temperature,changes,to,maintain,a,constant,internal,body,temperature,
5),Water,has,large,cohesive,forces,(,as,hydrogen,bonds,stick,together),so,allows,transportation,of,substan
ces(,water,travelling,in,columns,in,xylem),and,means,water,has,a,high,surface,tension,when,it,comes,into,
contact,with,air,(,allowing,pond,skaters,to,walk,on,its,surface)
Why,is,water,dipolar,?,,,ANS,-
As,water,is,made,up,of,two,hydrogen,atoms,and,one,oxygen,atom,,,the,hydrogen,atoms,have,a,slightly,po
sitive,pole,and,the,oxygen,atom,has,a,slightly,negative,pole,making,water,dipolar.
Hydrogen,bonds,,,ANS,-
Slightly,negatively,charged,oxygen,atom,is,attracted,to,the,slightly,positively,charged,hydrogen,atom,of,ot
her,water,molecules.,The,attraction,between,opposite,charges,is,called,hydrogen,bonding,,which,are,wea
k,bonds,but,strong,in,large,numbers.,This,makes,water,a,major,component,in,cells
Hydrolysis,,,ANS,-Breaks,a,bond,between,two,molecules,by,the,addition,of,a,molecule,of,water
Condensation,,,ANS,-
Joins,two,molecules,together,with,the,formation,of,a,bond,by,the,removal,of,a,molecule,of,water
Polymer,,,ANS,-
A,molecule,(,carbohydrate,,nucleotide,or,protein),made,up,of,many,monomers,(,small,repeating,units),joi
ned,together,by,condensation,reactions,and,broken,down,my,hydrolysis
,Monosaccharides,,,ANS,-
Are,the,monomers,from,which,larger,carbohydrates,are,made,and,contain,the,elements,C,H,and,O.,They,a
re,sweet,and,soluble,and,there,are,three,types,:,fructose,,,glucose,and,galactose.,Hexose,sugars,(glucose),
have,the,formula,C6H12O6
Glucose,is,the,product,of,photosynthesis,and,a,major,substrate,of,respiration,,,draw,the,two,structural,iso
mers,of,glucose,in,long,and,short,hand,and,state,the,difference,between,them,,,ANS,-
On,carbon,1,in,beta,glucose,the,hydroxyl,group,(OH),points,upwards,and,in,alpha,glucose,the,hydroxyl,gro
up,points,down,on,carbon,1
Sucrose,,,ANS,-Glucose,and,fructose
Maltose,,,ANS,-Glucose,and,glucose
Lactose,,,ANS,-Glucose,and,galactose
How,do,monosaccharides,join,together,,,ANS,-
By,condensation,to,form,a,glycosidic,bond,between,two,monosaccharides,and,a,disaccharide,and,a,molec
ule,of,water,are,formed
Disaccharide,,,ANS,-
Two,monosaccharides,joined,together,by,condensation,forming,a,glycosidic,bond.,There,are,three,types,:,
maltose,,sucrose,and,lactose.,They,have,the,chemical,formula,C12H22O11
Draw,the,hydrolysis,of,maltose,in,structural,formula,and,short,hand,formula,,,ANS,-
Test,for,starch,,,ANS,-
Add,iodine,solution,to,the,test,sample,,,if,starch,is,present,colour,changes,from,yellow,to,a,blue-
black,colour.
Test,for,a,reducing,sugar,,,ANS,-
Heat,with,Benedict's,reagent,(,blue),and,if,reducing,sugar,is,present,a,brick,red,precipitate,will,form
,Issues,with,the,Benedict's,test,?,,,ANS,-1),It,is,non,specific,-
,doesn't,tell,which,reducing,sugar,is,present,,,a,biosensor,can,be,used,to,detect,for,specific,sugars,
2),It's,qualitative,so,colour,change,is,being,measured,so,can't,obtain,concentration,of,reducing,sugar,but,a
llows,an,estimate,for,how,much,is,present,in,the,strength,of,the,colour
3),Is,subjective
How,to,quantify,results,on,the,concentration,of,unknown,glucose,concentration?,,,ANS,-
Use,a,colorimeter,,as,a,serial,dilution,of,known,glucose,concentrations,can,be,measured,producing,a,set,o
f,solutions,with,known,concentrations,.,The,Benedict's,test,can,be,performed,with,each,of,these,and,the,c
olour,intensity,measured.,A,CALIBRATION,CURVE,can,be,produced,from,the,results,and,used,to,read,iff,th
e,concentration,of,glucose,in,an,unknown,solution.
Test,for,a,non-reducing,sugar,?,,,ANS,-
Heat,the,sample,with,Benedict's,reagent,and,if,there,is,no,colour,change,a,reducing,sugar,is,not,present,b
ut,a,non-reducing,sugar,could,be.
Heat,a,fresh,sample,with,dilute,acid,(,which,will,hydrolyse,the,non,reducing,sugar,into,its,constituent,mon
osaccharides).
Neutralise,with,alkali,and,carry,out,the,Benedict's,test,again,
If,the,test,is,positive,for,a,non-reducing,sugar,it,will,form,a,brick,red,precipitate
Polysaccharide,,,ANS,-Three,main,types,-
,starch,,,glycogen,and,cellulose,which,are,chains,of,many,monomers,of,glucose,formed,in,condensation,re
actions.
Starch,,,ANS,-Starch,is,used,for,energy,storage,in,plants,and,is,made,from,condensation,of,alpha,glucose.
Amylose-,compact,helical,chains,so,store,lots,of,glucose,in,a,small,space,
Amylopectin,-
,branched,chains,which,allow,many,ends,to,be,quickly,hydrolysed,by,amylase,enzymes,to,release,glucose,
Insoluble,and,large,so,no,osmotic,effects,,,inert,and,cannot,diffuse,out,of,the,cells,which,they,are,stored,in
,.
Cellulose,,,ANS,-
Major,component,of,plant,cell,walls,made,up,of,beta,glucose,monomer,in,a,condensation,reaction.
, Chains,of,beta,glucose,molecules,form,long,straight,unbranched,chains.
These,chains,run,parallel,to,each,other,and,hydrogen,bonds,form,cross-
linkages,between,chains.,These,many,hydrogen,bonds,provide,high,tensile,strength,which,makes,the,cell,
wall,rigid,and,prevents,osmotic,lysis
Hydrogen,bonds,also,form,strong,fibres,called,microfibrils,which,are,grouped,into,fibres,which,provide,str
uctural,support.
Glycogen,,,ANS,-
Energy,storage,molecule,in,animals,found,in,liver,cells,and,in,muscle,tissue,and,is,made,from,the,condens
ation,of,alpha,glucose.,
Compact,so,store,lots,of,glucose,in,a,small,space,
Is,quickly,hydrolysed,to,release,soluble,glucose,as,many,ends,for,amylase,enzymes,to,attack,
Large,and,insoluble,so,no,osmotic,effects,,,inert,and,cannot,diffuse,out,of,the,cells,which,they,are,stored,i
n,.
Name,the,4,inorganic,ions,and,state,their,role,,,ANS,-
Inorganic,ions,occur,in,solution,in,the,cytoplasm,and,body,fluids,(,blood,,,tissue,fluid),
Hydrogen,ions,-,affects,pH,levels,,the,higher,the,concentration,of,H+,ions,the,lower,the,pH(,more,acid,),
Iron,ions,-
,important,component,of,haemoglobin,which,carries,oxygen,around,the,body,in,the,red,blood,cells,
Phosphate,ions,-
,component,of,DNA,,,ATP,,,RNA,and,phospholipids,,,bonds,between,phosphate,groups,store,energy,in,ATP
,
Sodium,ions,-,involved,in,the,absorption,of,glucose,and,amino,acids,in,co,transport,in,the,small,intestine
Amino,acids,,,ANS,-
Are,the,monomers,from,which,polypeptides,are,made.,Proteins,are,made,up,of,one,or,more,polypeptide,
chains.,All,amino,acids,contain,the,elements,C,H,O,and,N,and,are,made,up,of,an,amino,group,(NH2),,,a,car
boxylic,acid,group,(COOH),and,a,variable,group,(R)
What,is,a,conjugated,protein,?,,,ANS,-A,protein,with,a,non-protein,chemical,group,attached
Draw,the,structure,of,an,amino,acid,,,ANS,-
QUESTIONS WITH ACTUAL ANSWERS .
What,are,the,useful,properties,of,water,and,why,?,,,ANS,-1),Water,is,a,metabolite,-
,in,many,metabolic,reactions,including,condensation,and,hydrolysis,
2),Water,is,a,solvent,-
,medium,in,which,enzyme,catalysed,reactions,take,place,(metabolic,reactions,),and,readily,dissolves,subst
ances,like,inorganic,ions,(,as,water,is,dipolar,so,totally,surrounds,the,ions),,,excretory,products,(urea/am
monia),,,respiratory,gases,and,small,hydrophilic,molecules,(,amino,acids,,,etc)
3),Water,has,a,high,latent,heat,of,vaporisation,(lots,of,energy,required,to,break,hydrogen,bonds,between,
water,molecules,so,a,lot,of,energy,is,used,up,when,water,evaporates,),so,helps,with,temperature,control,
as,evaporation,of,sweat,cools,humans,down,
4),Water,has,a,high,specific,heat,capacity,(,to,separate,the,many,hydrogen,bonds,requires,a,lot,of,energy),
so,acts,as,a,buffer,and,resists,temperature,changes,to,maintain,a,constant,internal,body,temperature,
5),Water,has,large,cohesive,forces,(,as,hydrogen,bonds,stick,together),so,allows,transportation,of,substan
ces(,water,travelling,in,columns,in,xylem),and,means,water,has,a,high,surface,tension,when,it,comes,into,
contact,with,air,(,allowing,pond,skaters,to,walk,on,its,surface)
Why,is,water,dipolar,?,,,ANS,-
As,water,is,made,up,of,two,hydrogen,atoms,and,one,oxygen,atom,,,the,hydrogen,atoms,have,a,slightly,po
sitive,pole,and,the,oxygen,atom,has,a,slightly,negative,pole,making,water,dipolar.
Hydrogen,bonds,,,ANS,-
Slightly,negatively,charged,oxygen,atom,is,attracted,to,the,slightly,positively,charged,hydrogen,atom,of,ot
her,water,molecules.,The,attraction,between,opposite,charges,is,called,hydrogen,bonding,,which,are,wea
k,bonds,but,strong,in,large,numbers.,This,makes,water,a,major,component,in,cells
Hydrolysis,,,ANS,-Breaks,a,bond,between,two,molecules,by,the,addition,of,a,molecule,of,water
Condensation,,,ANS,-
Joins,two,molecules,together,with,the,formation,of,a,bond,by,the,removal,of,a,molecule,of,water
Polymer,,,ANS,-
A,molecule,(,carbohydrate,,nucleotide,or,protein),made,up,of,many,monomers,(,small,repeating,units),joi
ned,together,by,condensation,reactions,and,broken,down,my,hydrolysis
,Monosaccharides,,,ANS,-
Are,the,monomers,from,which,larger,carbohydrates,are,made,and,contain,the,elements,C,H,and,O.,They,a
re,sweet,and,soluble,and,there,are,three,types,:,fructose,,,glucose,and,galactose.,Hexose,sugars,(glucose),
have,the,formula,C6H12O6
Glucose,is,the,product,of,photosynthesis,and,a,major,substrate,of,respiration,,,draw,the,two,structural,iso
mers,of,glucose,in,long,and,short,hand,and,state,the,difference,between,them,,,ANS,-
On,carbon,1,in,beta,glucose,the,hydroxyl,group,(OH),points,upwards,and,in,alpha,glucose,the,hydroxyl,gro
up,points,down,on,carbon,1
Sucrose,,,ANS,-Glucose,and,fructose
Maltose,,,ANS,-Glucose,and,glucose
Lactose,,,ANS,-Glucose,and,galactose
How,do,monosaccharides,join,together,,,ANS,-
By,condensation,to,form,a,glycosidic,bond,between,two,monosaccharides,and,a,disaccharide,and,a,molec
ule,of,water,are,formed
Disaccharide,,,ANS,-
Two,monosaccharides,joined,together,by,condensation,forming,a,glycosidic,bond.,There,are,three,types,:,
maltose,,sucrose,and,lactose.,They,have,the,chemical,formula,C12H22O11
Draw,the,hydrolysis,of,maltose,in,structural,formula,and,short,hand,formula,,,ANS,-
Test,for,starch,,,ANS,-
Add,iodine,solution,to,the,test,sample,,,if,starch,is,present,colour,changes,from,yellow,to,a,blue-
black,colour.
Test,for,a,reducing,sugar,,,ANS,-
Heat,with,Benedict's,reagent,(,blue),and,if,reducing,sugar,is,present,a,brick,red,precipitate,will,form
,Issues,with,the,Benedict's,test,?,,,ANS,-1),It,is,non,specific,-
,doesn't,tell,which,reducing,sugar,is,present,,,a,biosensor,can,be,used,to,detect,for,specific,sugars,
2),It's,qualitative,so,colour,change,is,being,measured,so,can't,obtain,concentration,of,reducing,sugar,but,a
llows,an,estimate,for,how,much,is,present,in,the,strength,of,the,colour
3),Is,subjective
How,to,quantify,results,on,the,concentration,of,unknown,glucose,concentration?,,,ANS,-
Use,a,colorimeter,,as,a,serial,dilution,of,known,glucose,concentrations,can,be,measured,producing,a,set,o
f,solutions,with,known,concentrations,.,The,Benedict's,test,can,be,performed,with,each,of,these,and,the,c
olour,intensity,measured.,A,CALIBRATION,CURVE,can,be,produced,from,the,results,and,used,to,read,iff,th
e,concentration,of,glucose,in,an,unknown,solution.
Test,for,a,non-reducing,sugar,?,,,ANS,-
Heat,the,sample,with,Benedict's,reagent,and,if,there,is,no,colour,change,a,reducing,sugar,is,not,present,b
ut,a,non-reducing,sugar,could,be.
Heat,a,fresh,sample,with,dilute,acid,(,which,will,hydrolyse,the,non,reducing,sugar,into,its,constituent,mon
osaccharides).
Neutralise,with,alkali,and,carry,out,the,Benedict's,test,again,
If,the,test,is,positive,for,a,non-reducing,sugar,it,will,form,a,brick,red,precipitate
Polysaccharide,,,ANS,-Three,main,types,-
,starch,,,glycogen,and,cellulose,which,are,chains,of,many,monomers,of,glucose,formed,in,condensation,re
actions.
Starch,,,ANS,-Starch,is,used,for,energy,storage,in,plants,and,is,made,from,condensation,of,alpha,glucose.
Amylose-,compact,helical,chains,so,store,lots,of,glucose,in,a,small,space,
Amylopectin,-
,branched,chains,which,allow,many,ends,to,be,quickly,hydrolysed,by,amylase,enzymes,to,release,glucose,
Insoluble,and,large,so,no,osmotic,effects,,,inert,and,cannot,diffuse,out,of,the,cells,which,they,are,stored,in
,.
Cellulose,,,ANS,-
Major,component,of,plant,cell,walls,made,up,of,beta,glucose,monomer,in,a,condensation,reaction.
, Chains,of,beta,glucose,molecules,form,long,straight,unbranched,chains.
These,chains,run,parallel,to,each,other,and,hydrogen,bonds,form,cross-
linkages,between,chains.,These,many,hydrogen,bonds,provide,high,tensile,strength,which,makes,the,cell,
wall,rigid,and,prevents,osmotic,lysis
Hydrogen,bonds,also,form,strong,fibres,called,microfibrils,which,are,grouped,into,fibres,which,provide,str
uctural,support.
Glycogen,,,ANS,-
Energy,storage,molecule,in,animals,found,in,liver,cells,and,in,muscle,tissue,and,is,made,from,the,condens
ation,of,alpha,glucose.,
Compact,so,store,lots,of,glucose,in,a,small,space,
Is,quickly,hydrolysed,to,release,soluble,glucose,as,many,ends,for,amylase,enzymes,to,attack,
Large,and,insoluble,so,no,osmotic,effects,,,inert,and,cannot,diffuse,out,of,the,cells,which,they,are,stored,i
n,.
Name,the,4,inorganic,ions,and,state,their,role,,,ANS,-
Inorganic,ions,occur,in,solution,in,the,cytoplasm,and,body,fluids,(,blood,,,tissue,fluid),
Hydrogen,ions,-,affects,pH,levels,,the,higher,the,concentration,of,H+,ions,the,lower,the,pH(,more,acid,),
Iron,ions,-
,important,component,of,haemoglobin,which,carries,oxygen,around,the,body,in,the,red,blood,cells,
Phosphate,ions,-
,component,of,DNA,,,ATP,,,RNA,and,phospholipids,,,bonds,between,phosphate,groups,store,energy,in,ATP
,
Sodium,ions,-,involved,in,the,absorption,of,glucose,and,amino,acids,in,co,transport,in,the,small,intestine
Amino,acids,,,ANS,-
Are,the,monomers,from,which,polypeptides,are,made.,Proteins,are,made,up,of,one,or,more,polypeptide,
chains.,All,amino,acids,contain,the,elements,C,H,O,and,N,and,are,made,up,of,an,amino,group,(NH2),,,a,car
boxylic,acid,group,(COOH),and,a,variable,group,(R)
What,is,a,conjugated,protein,?,,,ANS,-A,protein,with,a,non-protein,chemical,group,attached
Draw,the,structure,of,an,amino,acid,,,ANS,-
