lipids

Question 1

what are the function of lipids (basic)?

Answer 1

energy source/store
protection of organs
waterproofing
thermal/electrical insulation
component in cell membranes

Question 2

what elements are in lipids?

Answer 2

carbon
hydrogen
oxygen

Question 3

what are the properties of lipids (water)?

Answer 3

non-polar (insoluble in water) but dissolve in non-polar organic substances

Question 4

what are triglycerides made of?

Answer 4

glycerol
3 fatty acids

Question 5

what bond is in a triglyceride?

Answer 5

ester bond (between glycerol and hydrocarbon chain)

Question 6

what happens during the formation of a triglyceride?

Answer 6

condensation reaction
ester bond is formed
3 waters are made as water molecules are removed

Question 7

what are saturated fatty acids?

Answer 7

all C atoms are joined by single bonds
all C atoms are linked to the maximum possible number of H atoms

Question 8

what are the properties of saturated fatty acids?

Answer 8

form straight lines
high melting point
molecules align readily so solid

Question 9

what are unsaturated fatty acids?

Answer 9

they have C double bonds

Question 10

what are the properties of unsaturated fatty acids?

Answer 10

form bent chains
low melting point
molecules can’t align readily so don’t solidify

Question 11

what are fatty acids with more than one double bond called?

Answer 11

mono-unsaturated or polyunsaturated fatty acids

Question 12

what are waxes?

Answer 12

lipids that melt at about 45 degrees C

Question 13

what are the function of waxes?

Answer 13

animals - insect exoskeleton
plants - leaf waxy cuticle and waterproofing

Question 14

what are lipoproteins?

Answer 14

complexes of lipids and proteins which occur in blood as plasma

Question 15

what are LDLs?

Answer 15

low-density lipoproteins

Question 16

where are LDLs formed from?

Answer 16

diets high in SATURATED fat

Question 17

what do LDLs do?

Answer 17

build up in blood vessels as fatty deposits in coronary arteries
restrict blood flow
result in angina or myocardial infraction or make an atheroma

Question 18

what are HDLs?

Answer 18

high-density lipoproteins

Question 19

where are HDLs formed from?

Answer 19

diets high in UNSATURATED fat

Question 20

what do HDLs do?

Answer 20

carry harmful fats away from artery walls to the liver for disposal

Question 21

what does the LDL:HDL ratio show?

Answer 21

the higher the ratio the higher the risk of cardio vascular and coronary heart disease

Question 22

what is cholesterol?

Answer 22

membrane component (precursor of other molecules)

Question 23

what are phospholipids?

Answer 23

similar structure to triglycerides but with a phosphate group instead of a fatty acid

Question 24

what do phospholipids do?

Answer 24

main component in cell membrane
electrical insulation in neurons

Question 25

what does a phospholipid contain?

Answer 25

hydrophilic head (negatively charged phosphate group interacts with water)
two hydrophobic tails (non-polar fatty acid that doesn’t interact with water)

Question 26

what happens when a phospholipid combines with water?

Answer 26

micelle (droplet sphere) forms
or
liposome (double layered phospholipid bilayer) forms

Question 27

what does a liposome do?

Answer 27

traps a compartment of water in the middle separated from external water by hydrophobic sphere