DNA is made up of many nucleotides, see the image below and clearly label the following feel free to use color the letters to indicate which is which.
- a) 5’and 3’ends
- b) deoxyribose (circle and label)
- c) one phosphate group (circle and label)
- d) bases (circle and label with their name)
- e) one phosphodiester bond
- f) the hydrogen atom that differentiates deoxyribose from ribose
- g) the base that identifies this as DNA vs RNA
- h) the chemical group on the base that defines it as a DNA base
- i) which atoms in each base would participate in base paring.
DNA usually takes the B‐DNA form; Look up which turn of the helix this is and bases per turn, as well as inclination of base from the helix axis.
- a) In the above 3 respects, how is B‐DNA different from Z‐DNA?
- b) Label the figures below with a clear indication of where the bases per turn start and end.
- c) Draw an axis for each helix
- d) Draw the turn of each helix.
Above is a stretch of DNA not drawn to scale of a chromosome in the process of replication. Address the pieces of missing information.
The double helices shown below represent negatively supercoiled, positively supercoiled and relaxed DNA – not necessarily shown in this order. These are all B‐DNA molecules 312 bp long
- a) label which is which
- b) Indicate which topological transitions are catalyzed by DNA topoisomerase I and which are catalyzed by DNA topoisomerase II
- c) Which molecule would be the least compact?
- a) What would be the sequence for the RNA primer? Note to which strand and where it will bind by rewriting it below. What makes the RNA primer?
- b) what will be the structure of the final product?
- c) What are the steps in this process?