T2:Nucleic acids

Question 1

what are individual nucleotides made up of ?

Answer 1

-a pentose sugar (5 carbon)
-phosphate group
-nitrogen containing base (C,T,G,A,U)

Question 2

What is the structure of Ribonucleic acid (RNA)?

Answer 2

-polymer made of nucleotides
-single ,short polynucleotide chain
-pentose sugar is always ribose
-Adenine, Guanine, Cytosine and URACIL base

Question 3

what is Deoxyribonucleic Acid (DNA) structure?

Answer 3

-Crick and Watson worked out the structure
-deoxyribose pentose sugar
–Adenine, THYMINEGuanine, Cytosine and Guanine base
-made of two extremely long polynucleotide chains joined by hydrogen bonds

Question 4

What are the specific base pairings?

Answer 4

-Adenine and thymine or (uracil)
-Guanine and cytosine
they are complimentary

Question 5

why is DNA a stable molecule?

Answer 5

-phosphodiester backbone protects chemically reactive bases in the helix
- C-G pairing forms 3 hydrogen bonds

Question 6

How is DNA adapted for its function?

Answer 6

-stables structure which passes generatons so it rarely mutates
-2 separate strands joined by hydrogen bonds which allows them to separate during DNA replication
-large molecule which carries alot of genetic information
-genetic info protected from chemical or physical forces as its within the cylinder
-base pairing alows replication and info to transfer as mRNA

Question 7

What are the 2 main ways cell division can occur?

Answer 7

-Nuclear division which is when the nucleus divides by mitosis or meiosis
-cytokinesis is where the whole cell divides

Question 8

What are the requirements for semi-conservative replication to take place?

Answer 8

-nucleotides with their bases must be present
-both strands on DNA to act as a template
-enzyme DNA polymerase
-chemical energy to drive the process

Question 9

How doe semi-conservative replication take place?

Answer 9

1) enzyme DNA helicase breaks the hydrogen bonds
2)helix unwinds and splits into 2 strands
3)exposed polynucleotide strands act as templates and free complimentary nucleotides bind by base pairing
4)nucleotides join by condensation reactions by DNA polymerase to from the other mising strand on the original polynucleotides

Question 10

What is the structure of adenosine triphosphate ATP?

Answer 10

-adenine (nitrogen containing base )
-ribose (pentose sugar )
-chain of three phospahtes

Question 11

How does ATP store energy?

Answer 11

-bonds between phosphate are unstable so have a low activation energy and easily broken
-when broken they release alot of energy
-only terminal phosphate is removed
Water is used to convet ATP into ADP(adenosine diphosphate) and reaction is catalysed by ATP hydrolase