L5 - carbon compounds and isomerism

Question 1

rank the functional groups from most to least polar

also solubility and b.p

Answer 1

amide> acid>alcohol>ketone/aldehyde> amine>ester>ether>alkane

Question 2

define alkyl

Answer 2

alkane missing 1 H atom

usually attached to another molecule

Question 3

how are alkyls named (eg meth)

Answer 3

methyl

Question 4

define aryl

Answer 4

functional group derived from simple aromatic ring eg phenyl

Question 5

what happens to lipid bilayer at low temps

Answer 5

gel phase

tightly packed

Question 6

what happens to bilayer at high temps

Answer 6

fluid phase

loosely packed

Question 7

when is E/Z nomenclature used
what is E
what is Z

Answer 7

for alkenes where every attached group is different
E - highest priority opposite
Z - highest priority same side

Question 8

what is an alkyne

Answer 8

C-C with triple bond

Question 9

what can affect membrane fluidity

Answer 9

length of FA chains
amount of C=C bonds
position of C=C bonds
cis/trans C=C bonds

Question 10

what is the bonding in alkynes

Answer 10

1 sigma

2 pi

Question 11

what are enantiomers

Answer 11

optical isomers

Question 12

how does b.p differ between alkenes alkanes alkynes

Answer 12

similar, but alkenes slightly lower due to inability to tightly pack

Question 13

describe steps of cahn ingold prelog (r/s) to determine enantiomers

Answer 13

1. chiral C in middle, place lowest priority group (4) in the top left
2. assign the remaining groups lowest to highest (1) priority in their positions around 4
3. draw an arrow in the direction 1-2-3 (ignore 4
4. if the arrow clockwise - R
   if arrow anticlockwise - S

Question 14

when determining R/S enantiomers , what does a clockwise arrow mean

Answer 14

R

Question 15

when determining R/S enantiomers , what does an anti-clockwise arrow mean

Answer 15

S

Question 16

what does laevorotary (L) (-) mean in relation to optical isomers

Answer 16

the optical isomer enantiomer that rotates plane polarised light to the left

Question 17

what does dextrorotary (D) (+) mean in relation to optical isomers

Answer 17

the optical isomer enantiomer that rotates plane polarised light to the right

Question 18

what is plane polarised light

Answer 18

light vibrations that occur on a single plane

Question 19

what is the name given to enantiomer that rotates plane polarised light to the left?

Answer 19

laevorotary (L) (-)

Question 20

what is the name given to enantiomer that rotates plane polarised light to the right?

Answer 20

dextrorotary (D) (+)

Question 21

what is keto - enol isomerism

Answer 21

an equilibrium between ketone(or aldehyde) and enol form of a molecule
there is interconversion between the two

Question 22

what are tautomer’s

Answer 22

the ketone(or aldehyde) form and enol form of a molecule (keto enol isomerism)

Question 23

how can interconversion between keto - enol isomers be catalysed

Answer 23

by acid/base/enzymes