AQA A Level Biology Unit 1

AQA A Level Biology Unit 1 questions
and answers 100% verified.


How do biological molecules provide evidence for evolution? correct answersThey all
have similar molecules and use the same amino acids and DNA.

What are monomers of carbohydrates called? correct answersMonosaccharides.

Beta Glucose correct answers

Alpha glucose correct answers

Glucose formula correct answersC₆H₁₂O₆

Name of the bond between monosaccharides? correct answersGlycosidic bond.

What is sucrose made from? correct answersGlucose and fructose.

What is lactose made from? correct answersGlucose and galactose.

What is maltose made from? correct answersTwo alpha glucose.

Testing for reducing sugars? correct answersAdd Benedict's reagent (blue) and heat
in a water bath at a boil. If present: Green → yellow → orange → brick red

Test for non-reducing sugars? correct answersAdd dilute hydrochloric acid and heat,
neutralise with Sodium Hydrogencarbonate and add Benedicts reagent.

What is the scientific name for carbohydrates? correct answersPolysaccharides.

What is starch made of? correct answersStarch is a mixture of two polysaccharides of
alpha glucose: Amylose and amylopectin.

, 2What is amylose? 2 2


correct answersA long, unbranched alpha glucose chain. The angles in it make it have a
2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2


coiled shape which makes it compact and effective for storage.
2 2 2 2 2 2 2 2 2 2
2


What is amylopectin? 2 2


correct answersA long, braqnched alpha glucose chain. The side branches mean that e
2 2 2 2 2 2 2 2 2 2 2 2 2


nzymes can get to and hydrolise glycosidic bonds faster so glucose can be released quickl
2 2 2 2 2 2 2 2 2 2 2 2 2 2


y. 2
2


What is glycogen? 2 2


correct answersA polysaccharide of alpha glucose with a similar structure to starch exce
2 2 2 2 2 2 2 2 2 2 2 2 2


pt it is more branched, allowing even faster energy release. It is also very compact.
2 2 2 2 2 2 2 2 2 2 2 2 2 2 2
2


What is celluose? 2 2


correct answersit is made of long. straight chains of beta glucose. The chains are linked
2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2


my hydrogen bonds to form microfibrils, a strong fibre. The strong fibres allow it to provide
2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2


structural support in cells as cell walls. 2 2 2 2 2 2 2
2


How to test for starch. correct answersAdd iodine which is dissolved in potassium iodie ti
2 2 2 2 2 2 2 2 2 2 2 2 2 2 2


the sample. Positive result: Turns blue-black. Negative result: stays brownyorange.
2 2 2 2 2 2 2 2 2 2
2


Which of proteins, polysaccharides and lipids are not a polymer. correct answersLipids.
2 2 2 2 2 2 2 2 2 2 2 2
2


What are triglycerides made of? correct answersGlycerol and fatty acids.
2 2 2 2 2 2 2 2 2 2
2


What causes lipids to be insoluble in water?
2 2 2 2 2 2 2


correct answersThe hydrophobic fatty acid tails.
2 2 2 2 2 2 2
2


What is the structure of a fatty acid? correct answers
2 2 2 2 2 2 2 2 2 2
2


What do double bonds cause in fatty acids? correct answersA kink in the chain.
2 2 2 2 2 2 2 2 2 2 2 2 2 2
2


Triglyceride formation? correct answers 2 2 2 2
2


What are phospholipids? 2 2


correct answersSimilar to triglycerides, but one of the fatty acid tails is replaced by a pho
2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2


sphate group head. 2 2 2
2


Which part of a phospholipid is hydrophillic and which part is hydrophobic?
2 2 2 2 2 2 2 2 2 2 2


2correct answersThe phosphate group is hydrophillic and the fatty acid tail is hydrophobic
2 2 2 2 2 2 2 2 2 2 2 2


. 2
2


What are triglycerides mainly used for?
2 2 2 2 2


correct answersTo store energy, they are effective at this as the hydrocarbon tails contai
2 2 2 2 2 2 2 2 2 2 2 2 2 2


n a lot of energy. They are also insoluble so do not affect the water potential of cells, preve
2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2


nting swelling. 2 2
2


How much energy do lipids contain compared to carbohydrates?
2 2 2 2 2 2 2 2


correct answersTwice as much energy per gram.
2 2 2 2 2 2 2 2
2


Why do triglycerides bundle together in water?
2 2 2 2 2 2


correct answersThe fatty acid tails are hydrophobic so face inwards, so are shielded by t
2 2 2 2 2 2 2 2 2 2 2 2 2 2 2


he glycerol heads.
2 2 2
2