AQA A – LEVEL BIOLOGY PAPER 2 AND PAPER 3 2020 QUESTION PAPER 2020

AQA A – LEVEL BIOLOGY PAPER 2 AND PAPER
3 2020 QUESTION PAPER 2020
What are monomers? - CORRECT ANSWER-The smaller units from which larger
molecules are made
What are polymers? - CORRECT ANSWER-Molecules made from a large number of
monomers joined together
What are examples of monomers? - CORRECT ANSWER-Monosaccharides, amino
acids and nucleotides
What happens in a condensation reaction? - CORRECT ANSWER-Two molecules are
joined together with the formation of a chemical bond, it involves the elimination of a
molecule of water
What happens in a hydrolysis reaction? - CORRECT ANSWER-The chemical bond
between two molecules is broken, it involves the use of water
All life on earth shares a common chemistry ... - CORRECT ANSWER-This provides
indirect evidence for evolution
The cells of all living organisms contain only a few ... - CORRECT ANSWER-Groups of
carbon-based compounds that interact in similar ways
Carbohydrates are commonly used by cells as respiratory substrates, - CORRECT
ANSWER-They also form structural components in plasma membranes and cell walls
Lipids have many uses, including ... - CORRECT ANSWER-The bilayer of plasma
membranes, certain hormones, and as respiratory substrates
Proteins form many cell structures, they are also important as ... - CORRECT
ANSWER-Enzymes, chemical messengers, and components of the blood
Nucleic acids carry the genetic code for ... - CORRECT ANSWER-The production of
proteins
What is the most common component of cells? - CORRECT ANSWER-Water
what happens in covalent bonding? - CORRECT ANSWER-atoms share a pair of
electrons in their outer shell
What happens in ionic bonding? - CORRECT ANSWER-ions with opposite charges
attract one another and form an ionic bond
what happens in hydrogen bonding? - CORRECT ANSWER-the negative region of a
polar molecule is attracted to the positive region of another polar molecule and a weak
electrostatic bond is formed between them both
what are all chemical processes that take place in living organisms collectively called? -
CORRECT ANSWER-metabolism
what is a molar solution? - CORRECT ANSWER-a solution which contains one mole of
solute in each litre of solution
what are atoms? - CORRECT ANSWER-the smallest unit of a chemical element that
can exist independently
if an atom loses or receives an electron, what does it become? - CORRECT ANSWERan ion
What are monosaccharides? - CORRECT ANSWER-The monomers from which larger
carbohydrates are made
What are examples of common monosaccharides? - CORRECT ANSWER-Glucose,
galactose, and fructose
What bond does a condensation reaction between two monosaccharides form? -
CORRECT ANSWER-Glycosidic
how are disaccharides formed? - CORRECT ANSWER-The condensation of two
monosaccharides
Maltose is a disaccharide formed by condensation of ... - CORRECT ANSWER-Two
glucose molecules
Sucrose is a disaccharide formed by condensation of ... - CORRECT ANSWERGlucose and fructose
Lactose is a disaccharide for bed by condensation of ... - CORRECT ANSWER-Glucose
and galactose
What are glucoses isomers? - CORRECT ANSWER-Alpha glucose and beta glucose
Polysaccharides are formed by ... - CORRECT ANSWER-The condensation of many
glucose units
Which polysaccharides are formed by the condensation of alpha glucose? - CORRECT
ANSWER-Glycogen and starch
Which polysaccharide is formed by the condensation of beta glucose? - CORRECT
ANSWER-Cellulose
what are all monosaccharides and some disaccharides? - CORRECT ANSWERreducing sugars
what is reduction? - CORRECT ANSWER-a chemical reaction involving the gain of
electrons or hydrogen
what is a reducing sugar? - CORRECT ANSWER-a sugar that can donate electrons to
another chemical
what is the test for reducing sugars known as? - CORRECT ANSWER-the benedicts
test
why is the test for reducing sugars known as the benedicts test? - CORRECT
ANSWER-benedicts reagent is used to test reducing sugars
how do you carry out the benedicts test? - CORRECT ANSWER-1. dissolve the food
sample in water
2.add an equal volume of benedicts reagent
3.heat in water bath
what colour will the benedicts reagent turn if a reducing sugar is present? - CORRECT
ANSWER-orange - brown
how do you test if a sugar is non-reducing? - CORRECT ANSWER-1.ensure its not a
reducing sugar by carrying out the benedicts test
2.add equal volumes of food sample and hydrochloric acid to a test tube
3.place in a water bath
4.add sodium hydrogencarbonate to neutralise the hydrochloric acid
5.complete the benedicts test with this solution