Exam (elaborations)
AQA A-Level Biology paper 1 2023 exam questions
- Course
- Institution
A-Level Biology paper 1 2023 exam practice paper for Mock. AQA A-Level Biology paper 1 2023 exam question (***IMPORTANT***)
[Show more]
Seller
Follow
AngelaSteven
Reviews received
Content preview
A-level Biology Paper 1 2023194 marks
Q1.
The diagram shows the structure of two α-glucose molecules.
(a) On the diagram, draw a box around one chemical group in each glucose molecule
used to form a glycosidic bond.
(1)
(b) A precipitate is produced in a positive result for reducing sugar in a Benedict’s test.
A precipitate is solid matter suspended in solution.
A student carried out the Benedict’s test. Suggest a method, other than using a
colorimeter that this student could use to measure the quantity of reducing sugar in
a solution.
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
(2)
Page 1 of 68
,In an investigation, a student wanted to identify the solutions in two beakers, A and B.
She knew one beaker contained maltose solution and the other beaker contained glucose
solution. Both solutions had the same concentration.
She did two separate biochemical tests on a sample from each beaker.
Test 1 – used Benedict’s solution to test for reducing sugar.
Test 2 – added the enzyme maltase, heated the mixture at 30 °C for 5 minutes, and then
Used Benedict’s solution to test for reducing sugar.
Maltose is hydrolysed by maltase.
The student’s results are shown in the table below.
Colour of solution after testing
with Benedict’s solution
Beaker Test 1 Test 2
A red red
B red dark red
(c) Explain the results for beakers A and B in the table.
Beaker A __________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
Beaker B __________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
(2)
(d) Use of a colorimeter in this investigation would improve the repeatability of the
student’s results.
Give one reason why.
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
(1)
In Test 1, the student used a measuring cylinder to measure 15 cm3 of solution from a
Page 2 of 68
, beaker. The measuring cylinder gives a volume with an uncertainty of ±1 cm3. She used a
graduated syringe to measure 5.0 cm3 of Benedict’s solution. The graduated syringe gives
a volume with an uncertainty of ± 0.5 cm3. She mixed these volumes of liquid to do the
biochemical test.
(e) Calculate the percentage error for the measurements used to obtain a 20 cm3
mixture of the solution from the beaker and Benedict’s solution. Show your working.
(2)
Answer = _____________________________%
(Total 8 marks)
Q2.
(a) What is a monomer?
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
(1)
(b) Lactulose is a disaccharide formed from one molecule of galactose and one
molecule of fructose.
Other than both being disaccharides, give one similarity and one difference between
the structures of lactulose and lactose.
Similarity ___________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
Difference __________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
(2)
(c) Following digestion and absorption of food, the undigested remains are processed
to form faeces in the parts of the intestine below the ileum.
Page 3 of 68
, The faeces of people with constipation are dry and hard. Constipation can be
treated by drinking lactulose. Lactulose is soluble, but is not digested or absorbed in
the human intestine.
Use your knowledge of water potential to suggest why lactulose can be used to help
people suffering from constipation.
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
(2)
(d) Lactulose can also be used to treat people who have too high a concentration of
hydrogen ions (H+) in their blood.
The normal range for blood H+ concentration is 3.55 × 10–8 to 4.47 × 10–8 mol dm–3
A patient was found to have a blood H+ concentration of 2.82 × 10–7 mol dm–3
Calculate the minimum percentage decrease required to bring the patient’s blood H+
concentration into the normal range.
Answer = ____________________
(2)
(Total 7 marks)
Q3.
(a) Describe a biochemical test to confirm the presence of protein in a solution.
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
Page 4 of 68
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller AngelaSteven. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $14.18. You're not tied to anything after your purchase.
Can Stuvia be trusted?
4.6 stars on Google & Trustpilot (+1000 reviews)
53068 documents were sold in the last 30 days
Founded in 2010, the go-to place to buy study notes for 14 years now