AQA A-LEVEL BIOLOGY RESPIRATION (3.5.2)
QUIZZES WITH ANSWERS UPDATED 2025 - 2026
What,is,glycolysis?,,,ANS,-The,first,stage,of,anaerobic,and,aerobic,respiration
Is,glycolysis,an,anaerobic,or,aerobic,process?,,,ANS,-Anaerobic
Where,does,glycolysis,occur?,,,ANS,-In,the,cytoplasm
Outline,the,process,of,glycolysis,(3),,,ANS,-
1.,Glucose,(6C),is,phosphorylated,to,form,glucose,phosphate,(6C),with,two,ATP,molecules,used,in,the,pro
cess
2.,Two,molecules,of,glucose,phosphate,(3C),are,used,to,form,two,molecules,of,triose,phosphate,(3C)
3.,Triose,phosphate,(3C),is,used,to,make,two,molecules,of,pyruvate,(3C),through,an,oxidation,reaction.,W
hile,this,occurs,,two,molecules,of,ADP,and,Pi,are,used,to,make,two,molecules,of,ATP,and,two,molecules,of
,NAD,are,reduced,to,form,two,molecules,of,NADH
Explain,why,the,net,gain,of,ATP,molecules,formed,from,glycolysis,is,two,,,ANS,-
Four,molecules,of,ATP,are,formed,during,glycolysis,however,,two,are,used,to,form,glucose,phosphate,so,t
he,overall,gain,is,2
What,products,are,formed,during,glycolysis?,(2),,,ANS,-1.,Two,molecules,of,pyruvate
2.,Two,molecules,of,NADH
If,respiration,is,aerobic,,what,happens,to,the,pyruvate,and,NADH,molecules,formed?,,,ANS,-
They,enter,the,mitochondrial,matrix,via,active,transport
Where,does,the,link,reaction,take,place?,,,ANS,-Mitochondrial,matrix
, Outline,the,process,of,the,link,reaction,(3),,,ANS,-
1.,Pyruvate,(3C),from,the,glycolysis,reaction,is,oxidised,to,acetate,(2C),,releasing,one,molecule,of,carbon,d
ioxide,(1C),in,the,process
2.,One,molecule,of,NAD,uses,the,hydrogen,atoms,lost,from,the,oxidation,of,pyruvate,to,form,one,molecul
e,of,reduced,NAD/NADH
3.,The,acetate,(2C),formed,as,a,result,of,the,oxidation,of,pyruvate,(3C),reacts,with,coenzyme,A,to,form,ac
etylcoenzyme,A,(2C)
Explain,why,the,overall,products,of,the,link,reaction,are,NOT,that,outlined,below.,State,what,they,should,
be,instead
1x,acetylcoenzymeA
1x,reduced,NAD/NADH
1x,CO2,,,ANS,-
The,link,reaction,occurs,twice,per,glucose,molecule,and,so,,it,should,be,two,molecules,of,acetylcoenzyme
A,,reduced,NAD/NADH,and,carbon,dioxide
How,is,the,6C,molecule,used,in,the,Krebs,Cycle,produced?,,,ANS,-
AcetylcoenzymeA,reacts,with,a,4C,molecule,,releasing,coenzymeA,to,be,used,during,the,link,reaction
Where,does,the,Krebs,Cycle,occur,in,eukaryotes?,,,ANS,-Mitochondrial,matrix
Where,does,the,Krebs,Cycle,occur,in,prokaryotes?,,,ANS,-The,cytoplasm
What,happens,to,the,6C,molecule,during,the,Krebs,Cycle?,,,ANS,-
Through,a,series,of,redox,reactions,,reduced,coenzymes,NADH,and,FADH2,are,formed
How,many,of,each,reduced,coenzyme,are,formed,during,the,Krebs,Cycle?,,,ANS,-
Three,molecules,of,reduced,NAD/NADH,and,one,molecule,of,reduced,FAD/FADH2
QUIZZES WITH ANSWERS UPDATED 2025 - 2026
What,is,glycolysis?,,,ANS,-The,first,stage,of,anaerobic,and,aerobic,respiration
Is,glycolysis,an,anaerobic,or,aerobic,process?,,,ANS,-Anaerobic
Where,does,glycolysis,occur?,,,ANS,-In,the,cytoplasm
Outline,the,process,of,glycolysis,(3),,,ANS,-
1.,Glucose,(6C),is,phosphorylated,to,form,glucose,phosphate,(6C),with,two,ATP,molecules,used,in,the,pro
cess
2.,Two,molecules,of,glucose,phosphate,(3C),are,used,to,form,two,molecules,of,triose,phosphate,(3C)
3.,Triose,phosphate,(3C),is,used,to,make,two,molecules,of,pyruvate,(3C),through,an,oxidation,reaction.,W
hile,this,occurs,,two,molecules,of,ADP,and,Pi,are,used,to,make,two,molecules,of,ATP,and,two,molecules,of
,NAD,are,reduced,to,form,two,molecules,of,NADH
Explain,why,the,net,gain,of,ATP,molecules,formed,from,glycolysis,is,two,,,ANS,-
Four,molecules,of,ATP,are,formed,during,glycolysis,however,,two,are,used,to,form,glucose,phosphate,so,t
he,overall,gain,is,2
What,products,are,formed,during,glycolysis?,(2),,,ANS,-1.,Two,molecules,of,pyruvate
2.,Two,molecules,of,NADH
If,respiration,is,aerobic,,what,happens,to,the,pyruvate,and,NADH,molecules,formed?,,,ANS,-
They,enter,the,mitochondrial,matrix,via,active,transport
Where,does,the,link,reaction,take,place?,,,ANS,-Mitochondrial,matrix
, Outline,the,process,of,the,link,reaction,(3),,,ANS,-
1.,Pyruvate,(3C),from,the,glycolysis,reaction,is,oxidised,to,acetate,(2C),,releasing,one,molecule,of,carbon,d
ioxide,(1C),in,the,process
2.,One,molecule,of,NAD,uses,the,hydrogen,atoms,lost,from,the,oxidation,of,pyruvate,to,form,one,molecul
e,of,reduced,NAD/NADH
3.,The,acetate,(2C),formed,as,a,result,of,the,oxidation,of,pyruvate,(3C),reacts,with,coenzyme,A,to,form,ac
etylcoenzyme,A,(2C)
Explain,why,the,overall,products,of,the,link,reaction,are,NOT,that,outlined,below.,State,what,they,should,
be,instead
1x,acetylcoenzymeA
1x,reduced,NAD/NADH
1x,CO2,,,ANS,-
The,link,reaction,occurs,twice,per,glucose,molecule,and,so,,it,should,be,two,molecules,of,acetylcoenzyme
A,,reduced,NAD/NADH,and,carbon,dioxide
How,is,the,6C,molecule,used,in,the,Krebs,Cycle,produced?,,,ANS,-
AcetylcoenzymeA,reacts,with,a,4C,molecule,,releasing,coenzymeA,to,be,used,during,the,link,reaction
Where,does,the,Krebs,Cycle,occur,in,eukaryotes?,,,ANS,-Mitochondrial,matrix
Where,does,the,Krebs,Cycle,occur,in,prokaryotes?,,,ANS,-The,cytoplasm
What,happens,to,the,6C,molecule,during,the,Krebs,Cycle?,,,ANS,-
Through,a,series,of,redox,reactions,,reduced,coenzymes,NADH,and,FADH2,are,formed
How,many,of,each,reduced,coenzyme,are,formed,during,the,Krebs,Cycle?,,,ANS,-
Three,molecules,of,reduced,NAD/NADH,and,one,molecule,of,reduced,FAD/FADH2
