BIOLOGY AQA AS 74011
PAPER 1 [WELL VERIFIED]
• The human cell then makes a complementary strand to the HIV
DNA.
The complementary strand is made in the same way as a new
complementary
strand is made during semi-conservative replication of human
DNA. Describe how the complementary stran...
• The human cell then makes a complementary strand to the HIV
DNA.
The complementary strand is made in the same way as a new
complementary
strand is made during semi-conservative replication of human
DNA. Describe how the complementary strand of HIV DNA is
made. - ANS✔✔---- there are complementary
nucleotides/bases pair
- DNA polymerase used
- Nucleotides join together (to form new strand)/phosphodiester
bonds form;
Contrast the structures of DNA and mRNA molecules to give
three differences. - ANS✔✔---- DNA is double stranded/double
helix and mRNA single-stranded;
- DNA (very) long and RNA short;
, -Thymine/T in DNA and uracil/U in RNA;
- Deoxyribose in DNA and ribose in RNA;
This fat substitute cannot be digested in the gut by lipase.
Suggest why. - ANS✔✔---- (Fat substitute) is a different/wrong
shape/not complementary
- Unable to fit/bind to (active site of) lipase/no ES complex
formed;
Despite being a lipid, the substitute cannot cross the cell-surface
membranes of cells lining the gut.
Suggest why it cannot cross cell-surface membranes. -
ANS✔✔---It is hydrophilic/is polar/is too large/is too big;
Cells constantly hydrolyse ATP to provide energy. Describe how
ATP is resynthesised in cells. - ANS✔✔---- From ADP and
phosphate;
- By ATP synthase;
- During respiration/photosynthesis;
Give two ways in which the hydrolysis of ATP is used in cells. -
ANS✔✔---- To provide energy for other reactions/named
process;
- To add phosphate to other substances and make them more
reactive/change their shape
What is the evidence from Figure 2 that a scanning electron
microscope was used to take this photograph? - ANS✔✔---
(Can see) 3D image
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 jackwa. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $22.49. You're not tied to anything after your purchase.
