Nucleic Acids, ATP & Water Flashcards
Name one way, other than circular DNA, in which prokaryotic DNA differs from eukaryotic DNA
Not associated with histones
If two organisms have a similar % of base pairs but are completely different, what’s responsible? (Following from a different order of base pairs)
Code for different AAs
Why is DNA different in a virus?
A=/= T
DNA single stranded
Events of interphase involve DNA replication, which involves…
Semi-conservative replication
What does the graph show about root growth (graph of mitosis index vs distance from root tip)
Faster mitosis growth nearer to tip
So must grow via mitosis
HSV attack’s nerve cells only. It has proteins complementary to what part of the nerve cell?
Receptors
Located on ITS membrane ONLY
Describe an inactive virus
No more cells get infected
B/c virus not replicating
List an advantage of programmed cell death
Stops virus replicating
How does HSV microRNA allow it to stay in body for years
Binds via specific base pairing
Preventing mRNA from being read by ribosomes
Which prevents protein translation
That causes cell death
Explain why DNA nucleotides are added in 5’ to 3’ direction only (1st mark)
Ref. to DNA polymerase
State evidence that DNA is a polymer
Repeating nucleotides
What is the minimum no. of DNA bases required to code for AAs if there are 51 AAs in the primary sequence?
153
Why are there a more bases in a gene for a particular polypeptide than minimum?
Introns present
Give one way in which ATP is good as a cell energy source?
Instantaneous release of energy
How is ATP useful for biological processes?
Involves a simple reaction
Why is it necessary for humans to synthesise large amounts of ATP
Can’t be stored
Small amounts of energy releases at a time
Advantage of ATP as energy storage in cell
Easily hydrolysed
Suggest how methylation of DNA prevents expression of gene
Prevents RNA polymerase binding
Which prevents complementary base pairing
So no translation of mRNA
What is the role of RNA polymerase during translation
Joins nucleotides together to form mRNA
What is meant by palindromic recognition sequence of DNA
DNA read the same both ways
The movement of the woodlice in low relative humidity is an advantage to their survival. Explain how
Low humidity = more wood lice moving
Increased movement = increased chance of leaving dry which reduces water loss
Explain why the following steps were necessary in finding the water content of straw:
(i)
heating the straw until it reaches constant mass
Ensure all water lost
(ii) Not heating straw above 90
Only water given off
Above 90, straw burnt
