AQA AS LEVEL BIOLOGY ACTUAL EXAM 2025 TEST
Top Grade Exam Answer Guide | Fully Explained Practice Papers with Learning
Pointers and Mistake Fixes
what is RNA? - ribonucleic acid
MRNA and TRNA
single stranded
shorter
AU CG
what are biological molecules? - molecules made and used by living organisms eg. lipids, carbs,
DNA, AT, water, inorganic ions
what are the functions of carbohydrates? - -energy source (respiration)
-energy store (starch and glycogen)
-structure (cellulose)
ATP structure? - 1 adenosine 3 phosphates
ADP and energy= ATP
condensation reaction using ATP synthase
carries energy in bonds
hydrolysis breaks down into ADP and energy using ATP hydrolase
releases energy from phosphate group bonds
what are the building blocks of carbohydrates called? - monosaccharides
,why is ATP a good source of energy? - immediate release, only need to break one bond
releases small amounts of energy at a time, manageable
examples of monosaccharides - glucose, fructose, galactose
uses of ATP? - protein synthesis
organelle synthesis
dna replication
mitosis
active transport
metabolic reactions
movement
homeostasis
formula for monosaccharides? - c6h12o6 -same formula but arranged differently
role of water in biology? - acts as a habitat for organisms
make up cytoplasm, tissue fluid, blood, xylem and phloem
water properties? - dipolar
partially positive hydrogen partially negative oxygen
so separate water molecules form hydrogen bonds with eachother
difference between alpha and beta glucose? - on carbon 1, alpha glucose has an OH group on
the bottom. beta glucose has it at the top.
,how are monosaccharides joined together? - condensation reaction between 2 OH groups
roles of water? - -habitat, high shc so a lot of heat needs to be applied before evaporation due
to hydrogen bonds. ice is less dense than water so floats up
-solvent, dipolar so separate solutes by charge depending on partial charge. solute dissolves in
water, useful for cytoplasm, diffusion and active transport ect
-hydrostatic pressure, when pressurised, water provides a strong pushing force particularly in
mass flow. supports turgidity
-homeostasis, sweat on skin uses blood heat to evaporate, cooling individual. sweat is made up
of hydrogen bonds,stable structure, large amount of heat to evaporate. LATENT HEAT OF
EVAPORATION.
bond in carbohydrate? - glycosidic
what are inorganic ions? - salts or minerals
don't contain carbon
eg sodium and chloride ions
examples of disaccharides - sucrose, lactose (glucose + galactose), maltose (glucose + glucose)
kingdoms of biology? - animal, plant, bacteria, fungi, protocista
animal and plant multicellular
others are microorganisms
viruses aren't living
all organisms made up of cells
eukaryotic vs prokaryotic - eukaryotic - membrane bound organelles eg. nucleus
, prokaryotic - no membrane bound organelles, smaller ribosomes
formula for disaccharides? - c12h22o11
what are the 2 forms of reproduction? - sexual- 2 parents each provide gamete which fuse to
make zygote which develops into organism
asexual- one parent to produce genetically identical offspring
how are polymers separated? - hydrolysis (addition of water)
how does a zygote develop into an organism? - stem cell, undifferentiated
divides by mitosis to make more stem cells
each cell differentiates into specialised
each specialised divides by mitosis to make tissues
different tissues for organ, and so on
what is a polysaccharide? - many monosaccharides joined together by condensation
reaction/glycosidic bonds.
structure of nucleus? - contains DNA wrapped around histones to form chromatin
double membrane called nuclear envelope with pores
nucleolus produces ribosomes and mRNA
nucleoplasm contains chromatin
examples of polysaccharides - -amylose, long chain of alpha glucose, makes starch/glycogen
-cellulose, long chain of beta glucose
Top Grade Exam Answer Guide | Fully Explained Practice Papers with Learning
Pointers and Mistake Fixes
what is RNA? - ribonucleic acid
MRNA and TRNA
single stranded
shorter
AU CG
what are biological molecules? - molecules made and used by living organisms eg. lipids, carbs,
DNA, AT, water, inorganic ions
what are the functions of carbohydrates? - -energy source (respiration)
-energy store (starch and glycogen)
-structure (cellulose)
ATP structure? - 1 adenosine 3 phosphates
ADP and energy= ATP
condensation reaction using ATP synthase
carries energy in bonds
hydrolysis breaks down into ADP and energy using ATP hydrolase
releases energy from phosphate group bonds
what are the building blocks of carbohydrates called? - monosaccharides
,why is ATP a good source of energy? - immediate release, only need to break one bond
releases small amounts of energy at a time, manageable
examples of monosaccharides - glucose, fructose, galactose
uses of ATP? - protein synthesis
organelle synthesis
dna replication
mitosis
active transport
metabolic reactions
movement
homeostasis
formula for monosaccharides? - c6h12o6 -same formula but arranged differently
role of water in biology? - acts as a habitat for organisms
make up cytoplasm, tissue fluid, blood, xylem and phloem
water properties? - dipolar
partially positive hydrogen partially negative oxygen
so separate water molecules form hydrogen bonds with eachother
difference between alpha and beta glucose? - on carbon 1, alpha glucose has an OH group on
the bottom. beta glucose has it at the top.
,how are monosaccharides joined together? - condensation reaction between 2 OH groups
roles of water? - -habitat, high shc so a lot of heat needs to be applied before evaporation due
to hydrogen bonds. ice is less dense than water so floats up
-solvent, dipolar so separate solutes by charge depending on partial charge. solute dissolves in
water, useful for cytoplasm, diffusion and active transport ect
-hydrostatic pressure, when pressurised, water provides a strong pushing force particularly in
mass flow. supports turgidity
-homeostasis, sweat on skin uses blood heat to evaporate, cooling individual. sweat is made up
of hydrogen bonds,stable structure, large amount of heat to evaporate. LATENT HEAT OF
EVAPORATION.
bond in carbohydrate? - glycosidic
what are inorganic ions? - salts or minerals
don't contain carbon
eg sodium and chloride ions
examples of disaccharides - sucrose, lactose (glucose + galactose), maltose (glucose + glucose)
kingdoms of biology? - animal, plant, bacteria, fungi, protocista
animal and plant multicellular
others are microorganisms
viruses aren't living
all organisms made up of cells
eukaryotic vs prokaryotic - eukaryotic - membrane bound organelles eg. nucleus
, prokaryotic - no membrane bound organelles, smaller ribosomes
formula for disaccharides? - c12h22o11
what are the 2 forms of reproduction? - sexual- 2 parents each provide gamete which fuse to
make zygote which develops into organism
asexual- one parent to produce genetically identical offspring
how are polymers separated? - hydrolysis (addition of water)
how does a zygote develop into an organism? - stem cell, undifferentiated
divides by mitosis to make more stem cells
each cell differentiates into specialised
each specialised divides by mitosis to make tissues
different tissues for organ, and so on
what is a polysaccharide? - many monosaccharides joined together by condensation
reaction/glycosidic bonds.
structure of nucleus? - contains DNA wrapped around histones to form chromatin
double membrane called nuclear envelope with pores
nucleolus produces ribosomes and mRNA
nucleoplasm contains chromatin
examples of polysaccharides - -amylose, long chain of alpha glucose, makes starch/glycogen
-cellulose, long chain of beta glucose
