Lipids

Question 1

chemistry and types of lipids

Answer 1

lipids are organic molecules that are hydrophobic, monomer is fatty acids

there are complex lipids (made with fatty acids) and lipids not make from fatty acids (steroids eg cholestrol)

Question 2

function of lipids

Answer 2

energy storage
insulation
pigments
cofactors for enzymes
plasma membrane
signalling molecules
water repellant

Question 3

naming fatty acids

Answer 3

number of carbons: number of double bonds (triangle C with carbon)
numbering Cs from the carboxyl carbon

Question 4

define fatty acids

Answer 4

long chain carboxylic acids (alkyl chains with a terminal carboxyl group)

Question 4

saturated vs unsaturated FA

Answer 4

only single bonds between C atoms/ contain 1 or more double bonds between C atoms (mono/polyunsaturated)

Question 5

cis vs trans FA

Answer 5

H atoms bonded to the C atoms held in the double bond are on the same side/opposite sides of the carbon chain
trans: increase shelf life and stability

Question 6

essential vs non essential FA

Answer 6

cannot/ can be synthesised from the body and must be consumed

Question 7

structure and function of triglycerides (triacylglycerols)

Answer 7

condensation reaction between glycerol and 3 fatty acids (ester bond)

glycerol: polar, hydrophillic
long term store of energy
because theres lots of energy in C-C and C-H bonds

Question 8

phospholipids structure and function

Answer 8

glycerol backbone, 2 fatty acids, 1 phosphate, 1 alcohol
phosphodiester bond between phosphate and glycerol
amphiphillic, part of molecule is hydrophobic, other part is hydrophillic

makes up phospholipid bilayer for plasma membrane

Question 9

cholestrol structure and function

Answer 9

made of interconnected rings, packs into plasma membrane, enhances order of phospholipids, decreases membrane permeability, important for myelin and neurons

Question 10

other steroids function

Answer 10

synthesis of bile acids
steroid hormones
vitamin D