lipids

Question 1

what are 2 types of lipids

Answer 1

triglycerides
phospholipids

Question 2

what three types of element make up lipids

Answer 2

carbon, hydrogen, oxygen

Question 3

what is a key feature of triglycerides

Answer 3

they are a good source of energy (also found in plants)

Question 4

what is a key feature of phospholipids

Answer 4

structural role
build up cell membranes

Question 5

what are lipids called

Answer 5

complex molecules
macromolecules
they are not polymers because the sub units are joined together but not in a repeating pattern

Question 6

are lipids polymers, (why not)

Answer 6

lipids are not polymers, they are macromolecules ( large and complex molecules)
although in lipids subunits are joined together, they are not joined together in a repeating pattern.

Question 7

are lipids polar, or non polar molecules

Answer 7

lipids are non polar molecules, they will not dissolve in water

Question 8

what is glycerol

Answer 8

glycerol is an organic alcohol which has 3 hydroxyl groups (-oh) groups

Question 9

what are fatty acids (in terms of acids/ alcohols)

Answer 9

fatty acids are organic acids that have a carboxyl group cooh joined to a hydrocarbon tail.
fatty acids are a type of carboxylic acids.

Question 10

instead of drawing out a whole fatty acid, the diagram can be summarised by showing a carboxyl group -COOH attached to what

Answer 10

R- can be used to depict the hydrocarbon chain, instead of drawing it out.

Question 11

what type of triglyceride are fats

Answer 11

fats are saturated triglycerides

Question 12

what type of triglycerides are oils

Answer 12

oils are unsaturated triglycerides

Question 13

at room temperature, what state are unsaturated triglycerides

Answer 13

unsaturated triglycerides are liquid at room temperature

Question 14

at room temperature what state are saturated triglycerides

Answer 14

saturated triglycerides are solid at room temperature

Question 15

what does monunsaturated mean

Answer 15

fatty acids with only one double bond between carbon atoms in the hydrocarbon chain

Question 16

what does poly unsaturated mean

Answer 16

fatty acids with more than one double bond between carbon atoms in the hydrocarbon chain

Question 17

why are unsaturated fatty acids liquid at room temperature

Answer 17

-the prescence of double bonds between the carbon atoms in the hydrocarbon chain causes the fatty acid chains to bend
this bending pushes the triglyceride molecules further apart from each other than saturated triglyceride molecules.
the double bonds kink the carbon chain so unsaturated fats cannot pack together tightly
the spaces between the triglyceride molecules weakens the intermolecular forces forming a liquid at room temperature

Question 18

why are saturated fatty acids solid at room temperature and compact

Answer 18

there are stronger intermolecular forces between the triglyceride molecules because they are closely packed together.

Question 19

role of phospholipids
and why do they have one unsaturated fatty acid chain and one saturated fatty acid chain.

Answer 19

phospholipids have a structural role
they do not store fats
phospholipid bilayer due to hydrophillic head and hydrophobic fatty acid chains which point towards centre of the sheet and the hydrophillic heads are positioned outwards, they protect the fatty acid chains from the water.

Question 20

phospholipid monolayer

Answer 20

hydrophillic head of phospholipid molecule sticking into the water and the fatty acid tails stick out of the water

Question 21

cholesterol structure

Answer 21

the hydroxyl group is polar and therefore hydrophyllic and the rest of the molecule is hydrophobic

Question 22

where does the body manufacture sterol

Answer 22

body manufactures sterols in the liver and the intestines it has an important role in the formation of cell membranes

Question 23

what is manufactured using cholesterol

Answer 23

vitamin D
bile
steroid hormones

Question 24

what are biological roles of lipids

Answer 24

-membrane formation and the creation of hydrophobic barriers
-hormone production
-electrical insulation necessary for nerve impulse transmission
waterproofing for examples birds feathers lipids are non polar hydrophobic

Question 25

roles of triglycerides

Answer 25

thermal insluation to reduce heat loss for example penguins
cushioning to protect vital organs such as heart kidneys
bouyancy for aquatic animals such as whales