Polymers and Life - DNA/RNA and Spectroscopy

Question 1

what does a nucleotide consist of?

Answer 1

phosphate

sugar

base

Question 2

which groups on the phosphate will react with the sugar?

Answer 2

the two alcohol groups

Question 3

which groups on ribose and deoxyribose will react with the phosphate?

Answer 3

the two alcohol groups on the left when in same orientation as on the datasheet

Question 4

which groups on the nitrogenous bases will react with the pentose sugars?

Answer 4

the H-N group on the left of the molecule when oriented like on the datasheet

Question 5

why can G + C and A + T only pair with each other?

Answer 5

because C

G+C have 3 hydrogen bonding sites on the same side of the molecules whereas A+T only have 2, so they cannot bond properly to each other

Question 6

what is the difference between transcription + translation in a level bio and a level chem?

Answer 6

no splicing in chem, focus more on bonding than wider effects

Question 7

what assumption is made in mass spectrometry?

Answer 7

all ions are +1 charge

Question 8

if a molecule is used in mass spectrometry, what will usually happen?

Answer 8

the molecule will usually split into fragments due to ionisation

Question 9

what is the molecular ion peak in mass spectrometry?

Answer 9

the heaviest ion - also the molecular mass of the compound

Question 10

what is the base peak?

Answer 10

the most abundant ion, other fragments are compared to this

Question 11

what is the difference between high res M+ peak and mass spectrometry?

Answer 11

high res M+ peak can measure mass to 4 decimal places, so compounds with very similar masses can be identified seperately

Question 12

what are the two axis on a mass spectrometry graph?

Answer 12

x = m/z ratio

y = frequency

Question 13

what does NMR stand for?

Answer 13

nuclear magnetic resonance

Question 14

what are the two types of NMR?

Answer 14

carbon 13

hydrogen 1

Question 15

what are the axis on a carbon 13 NMR graph?

Answer 15

x - chemical shift

y - intensity

Question 16

what is chemical shift measured in?

Answer 16

ppm

Question 17

what does the intensity show about the number of carbons in each environment?

Answer 17

nothing

Question 18

what shows the number of environments in an carbon 13 NMR graph?

Answer 18

number of peaks

Question 19

what are the differences between carbon 13 nmr and proton nmr?

Answer 19

area under peak gives relative abundance of protons in each area - not same for carbon 13

protons more abundant than carbon so more accurate readings

split peaks in high res proton nmr

Question 20

how can split peaks be interpreted in proton nmr?

Answer 20

the number of split peaks is one more than the number of hydrogens on a neighbouring carbon atom

Question 21

what is the n+1 rule?

Answer 21

number of split peaks in proton nmr is one more than the number of hydrogens on a neighbouring carbon

Question 22

when will a split peak not show on proton nmr?

Answer 22

hydrogens seperated by atoms other than carbon

hydrogens on adjacent carbons with the same environment will show as one big split not two seperate