biological molecules (lipids)

Question 1

what is a lipid made from?

Answer 1

glycerol and 3 fatty acids

Question 2

what bonds are present in lipids?

Answer 2

ester bonds

Question 3

what is a saturated fatty acid?

Answer 3

fatty acid with no double bonds

Question 4

what is an unsaturated fatty acid?

Answer 4

fatty acid with at least one double bond, which causes a kink in the chain

Question 5

what is a phospholipid?

Answer 5

where one fatty acid is replaced by a phosphate group, makes up a bilayer

Question 6

what is a triglyceride?

Answer 6

one molecule of glycerol with 3 fatty acids attached

Question 7

what is hydrophillic/hydrophobic in a phospholipid?

Answer 7

phosphate group is hydrophillic, fatty acid tails are hydrophobic

Question 8

what is the purpose of a triglyceride?

Answer 8

energy storage molecule

Question 9

how are triglycerides adapted?

Answer 9

long, hydrocarbon tails contain lots of chemical energy

insoluble so don’t affect the water potential of a cell

Question 10

what does hydrophillic mean?

Answer 10

attracted to water

Question 11

what does hydrophobic mean?

Answer 11

water repelling

Question 12

what is the purpose of a phospholipid?

Answer 12

makes up the bilayer of a cell membrane, which controls what enters and leaves a cell

Question 13

how is a phospholipid adapted?

Answer 13

heads are hydrophillic and tails are hydrophobic so can form a bilayer
centre is hydrophobic so acts as a barrier to water soluble substances

Question 14

how do you carry out an emulsion test for lipids?

Answer 14

shake the test substance with ethanol so that it dissolves
pour the solution into water
lipid shows up as a milky emulsion