AQA Biology Paper 3 Essay Plan Examples:
1. Importance of ATP
AO1- Co transport of glucose- ATP needed for sodium potassium pump.
A02- Importance of glucose for aerobic respiration- glycolysis instead of anaerobic.
No glucose= anaerobic respiration= less ATP produced (2) for metabolic reactions
like muscle contractions or condensation/ hydrolysis reactions= lactic acid
produced in mammals which is toxic.
AO1- Process of translation and forming a protein/enzyme from a polypeptide
chain.
AO2- Importance of proteins and enzymes (e.g. importance of amylase and
maltase for starch digestion and glucose absorption. No amylase and maltose= no
glucose= no uptake for respiration= no ATP for other metabolic processes e.g.
muscle contractions).
AO1- Second messenger model process- ATP needed for conversion to cyclic AMP.
AO2- No ATP= no cyclic AMP= no protein kinase A= no stimulation for enzyme
reaction causing glycogenolysis= low blood glucose levels in terms of water
potential (low BG= high WP of blood= water moves into cells from blood by
osmosis= low blood volume and pressure= fainting dizziness etc).
AO1- Process of translocation of sucrose in plants- ATP used in active transport of
sucrose from companion cells to phloem.- AO2- No ATP= no sucrose in phloem= no
mass transport to source cells= no glucose to be used for energy storage as starch
in plants or used structurally as cellulose. Either way not able to be used as no ATP
for the condensation reactions.
2. Importance of cycles
AO1- Process of the nitrogen cycle
AO2- Importance of nitrogen-containing compounds. No nitrates into plants= no
nitrogen available to create DNA nucleotides for semi-conservative replication in
mitosis= plant unable to grow.
AO1- ATP cycle process
AO2- Importance of ATP in second messenger model. No ATP converted to cyclic
AMP= no protein kinase a activated= no enzyme reaction stimulated for
glycogenolysis= no raise in blood glucose levels= high WP of blood still= water
moves into cells by osmosis= low volume of blood=low pressure of blood=
fainting, dizziness and swelling/oedema of parts of the body.
AO1- Negative feedback of high blood glucose levels
AO2- Importance of returning blood glucose levels back to optimum. If BGL remain
high, WP of blood decreases= water moves out of cells into blood by osmosis=
cells dehydrated= blood volume increases= blood pressure increases= higher
chance of developing atheroma= thrombosis= increased risk of cardiovascular
diseases.
AO1- Calvin cycle and LIR process
AO2- Importance of organic substances coming from the Calvin cycle. Organic
substance such as glucose can be used to create the polymer cellulose in plants
which is structural= high tensile strength for the plants= prevents plasmolysis (cell
shrinkage) or osmotic lysis (cells bursting)
3. Importance of metabolic ions:
AO1- Sodium- process of co-transport or sodium and amino acids.
AO2- Importance of amino acids= no translation of a polypeptide chain= no protein
form (e.g. haemoglobin)= no oxygen able to bind/ be transported around body= no
aerobic respiration, only anaerobic= less ATP and toxic lactic acid produced).
AO1- Hydrogen- process of chemiosmosis in LDR of photosynthesis.
, AO2- importance of chemiosmosis in photophosphorylation= used in ATP synthase
to create ATP, as well as reduction of NADP= both of which used in LIR of
photosynthesis. No ATP or NADPH then no LIR= no organic substance produced
(e.g. glucose) to be used for aerobic respiration= less ATP produced= no ATP for
muscle contractions.
AO1- Nitrogen- process of nitrogen cycle
AO2- importance of nitrogen- containing substances- nucleotides. No nucleotides=
no semi-conservative replication= no DNA polymerase forming new strands of
DNA= no mitosis or meiosis= no no cell growth but also no formation of tumours as
no uncontrolled cell division.
AO1- Iron- Haemoglobin is a protein made from amino acid monomers which
contain iron in their variable R group- protein structure paragraph.
AO2- no iron in R group= haemoglobin formed= no oxygen able to bind/ be
transported around body= no aerobic respiration, only anaerobic= less ATP and
toxic lactic acid produced).
4. Importance of complimentary shapes:
AO1- Process of lowering blood glucose levels to optimum using insulin- Insulin is a
protein complimentary shape to the receptors on liver/ muscle target cells.
AO2- Importance of lowering blood glucose levels. High BGL= low WP= water
moves from cells into the blood= high blood volume= high blood pressure= cells
dehydrated= blood volume increases= blood pressure increases= higher chance of
developing atheroma= thrombosis= increased risk of cardiovascular diseases.
AO1- Process of transcription factors binding to DNA promoter region and
stimulating DNA replication- Transcriptional factor is usually a protein so will have a
specific 3D shape, complimentary to the base sequence of a promoter region.
AO2- Importance of transcriptional factors binding to the promoter region of DNA=
tumour suppressor gene able to be transcribed= functional P53 protein
synthesised in translation= cell division inhibited and apoptosis of faulty cells
stimulated. If no tumour suppressor gene transcribed or translated= cells divide
uncontrollably which can cause tumours some of which may metastasise and be
malignant (cancerous).
AO1- Process of humoral response- B plasma cells produce antibodies which are
proteins so have a specific 3D shape, complimentary to the tertiary structure of an
antigen.
AO2- Importance of antibodies= stimulates phagocytosis of pathogen as causes
agglutination with antibody-antigen complexes. Humoral response also produces B
memory cells which remain in blood for a rapid second response to exposure to the
same antigen= produce antigens that are complimentary to antigen.
AO1- Process of co-transport of sodium ions and glucose- Channel protein on
membrane of ileum epithelial cells are complimentary to the shape of sodium and
glucose together, allowing both to enter the cells.
AO2- importance of glucose absorption= glucose
5. The causes and importance of variation and diversity in organisms
AO1- Meiosis- process of meiosis including crossing over and independent
segregation of homologous chromosomes
AO2- Importance of meiosis- creates 4 daughter cells that are genetically
difference.
AO1- mutations arising. Mutations arise by exposure to mutagenic agents (e.g. UV
light, smoking etc). Mutations replicated by mitosis.
AO2- In bacteria such as E.coli, these mutations can lead to antibiotic resistance,
whilst not important to humans or animals, these bacteria with the mutation are
able to survive the antibiotics and reproduce by binary fission. These mutations are
1. Importance of ATP
AO1- Co transport of glucose- ATP needed for sodium potassium pump.
A02- Importance of glucose for aerobic respiration- glycolysis instead of anaerobic.
No glucose= anaerobic respiration= less ATP produced (2) for metabolic reactions
like muscle contractions or condensation/ hydrolysis reactions= lactic acid
produced in mammals which is toxic.
AO1- Process of translation and forming a protein/enzyme from a polypeptide
chain.
AO2- Importance of proteins and enzymes (e.g. importance of amylase and
maltase for starch digestion and glucose absorption. No amylase and maltose= no
glucose= no uptake for respiration= no ATP for other metabolic processes e.g.
muscle contractions).
AO1- Second messenger model process- ATP needed for conversion to cyclic AMP.
AO2- No ATP= no cyclic AMP= no protein kinase A= no stimulation for enzyme
reaction causing glycogenolysis= low blood glucose levels in terms of water
potential (low BG= high WP of blood= water moves into cells from blood by
osmosis= low blood volume and pressure= fainting dizziness etc).
AO1- Process of translocation of sucrose in plants- ATP used in active transport of
sucrose from companion cells to phloem.- AO2- No ATP= no sucrose in phloem= no
mass transport to source cells= no glucose to be used for energy storage as starch
in plants or used structurally as cellulose. Either way not able to be used as no ATP
for the condensation reactions.
2. Importance of cycles
AO1- Process of the nitrogen cycle
AO2- Importance of nitrogen-containing compounds. No nitrates into plants= no
nitrogen available to create DNA nucleotides for semi-conservative replication in
mitosis= plant unable to grow.
AO1- ATP cycle process
AO2- Importance of ATP in second messenger model. No ATP converted to cyclic
AMP= no protein kinase a activated= no enzyme reaction stimulated for
glycogenolysis= no raise in blood glucose levels= high WP of blood still= water
moves into cells by osmosis= low volume of blood=low pressure of blood=
fainting, dizziness and swelling/oedema of parts of the body.
AO1- Negative feedback of high blood glucose levels
AO2- Importance of returning blood glucose levels back to optimum. If BGL remain
high, WP of blood decreases= water moves out of cells into blood by osmosis=
cells dehydrated= blood volume increases= blood pressure increases= higher
chance of developing atheroma= thrombosis= increased risk of cardiovascular
diseases.
AO1- Calvin cycle and LIR process
AO2- Importance of organic substances coming from the Calvin cycle. Organic
substance such as glucose can be used to create the polymer cellulose in plants
which is structural= high tensile strength for the plants= prevents plasmolysis (cell
shrinkage) or osmotic lysis (cells bursting)
3. Importance of metabolic ions:
AO1- Sodium- process of co-transport or sodium and amino acids.
AO2- Importance of amino acids= no translation of a polypeptide chain= no protein
form (e.g. haemoglobin)= no oxygen able to bind/ be transported around body= no
aerobic respiration, only anaerobic= less ATP and toxic lactic acid produced).
AO1- Hydrogen- process of chemiosmosis in LDR of photosynthesis.
, AO2- importance of chemiosmosis in photophosphorylation= used in ATP synthase
to create ATP, as well as reduction of NADP= both of which used in LIR of
photosynthesis. No ATP or NADPH then no LIR= no organic substance produced
(e.g. glucose) to be used for aerobic respiration= less ATP produced= no ATP for
muscle contractions.
AO1- Nitrogen- process of nitrogen cycle
AO2- importance of nitrogen- containing substances- nucleotides. No nucleotides=
no semi-conservative replication= no DNA polymerase forming new strands of
DNA= no mitosis or meiosis= no no cell growth but also no formation of tumours as
no uncontrolled cell division.
AO1- Iron- Haemoglobin is a protein made from amino acid monomers which
contain iron in their variable R group- protein structure paragraph.
AO2- no iron in R group= haemoglobin formed= no oxygen able to bind/ be
transported around body= no aerobic respiration, only anaerobic= less ATP and
toxic lactic acid produced).
4. Importance of complimentary shapes:
AO1- Process of lowering blood glucose levels to optimum using insulin- Insulin is a
protein complimentary shape to the receptors on liver/ muscle target cells.
AO2- Importance of lowering blood glucose levels. High BGL= low WP= water
moves from cells into the blood= high blood volume= high blood pressure= cells
dehydrated= blood volume increases= blood pressure increases= higher chance of
developing atheroma= thrombosis= increased risk of cardiovascular diseases.
AO1- Process of transcription factors binding to DNA promoter region and
stimulating DNA replication- Transcriptional factor is usually a protein so will have a
specific 3D shape, complimentary to the base sequence of a promoter region.
AO2- Importance of transcriptional factors binding to the promoter region of DNA=
tumour suppressor gene able to be transcribed= functional P53 protein
synthesised in translation= cell division inhibited and apoptosis of faulty cells
stimulated. If no tumour suppressor gene transcribed or translated= cells divide
uncontrollably which can cause tumours some of which may metastasise and be
malignant (cancerous).
AO1- Process of humoral response- B plasma cells produce antibodies which are
proteins so have a specific 3D shape, complimentary to the tertiary structure of an
antigen.
AO2- Importance of antibodies= stimulates phagocytosis of pathogen as causes
agglutination with antibody-antigen complexes. Humoral response also produces B
memory cells which remain in blood for a rapid second response to exposure to the
same antigen= produce antigens that are complimentary to antigen.
AO1- Process of co-transport of sodium ions and glucose- Channel protein on
membrane of ileum epithelial cells are complimentary to the shape of sodium and
glucose together, allowing both to enter the cells.
AO2- importance of glucose absorption= glucose
5. The causes and importance of variation and diversity in organisms
AO1- Meiosis- process of meiosis including crossing over and independent
segregation of homologous chromosomes
AO2- Importance of meiosis- creates 4 daughter cells that are genetically
difference.
AO1- mutations arising. Mutations arise by exposure to mutagenic agents (e.g. UV
light, smoking etc). Mutations replicated by mitosis.
AO2- In bacteria such as E.coli, these mutations can lead to antibiotic resistance,
whilst not important to humans or animals, these bacteria with the mutation are
able to survive the antibiotics and reproduce by binary fission. These mutations are
