lipids Flashcards
what do lipids contain
carbon, hydrogen, oxygen
are lipids polar or non-polar
non-polar
what are the functions of lipids
- energy source and storage- 1g of fat provides twice as much energy as carbs
- protection- protect vital organs from physical damage
- oxidation of triglycerides- produce metabolic water (camels)
- membranes- phospholipids are important component of all biological molecules
- waterproofing- leaves waxy cuticle to prevent water loss
- insulating- retain body heat, also provides electrical insulation around long nerve cells
- hormones- some hormones are lipids
what are lipids stored in
adipose cells in fat stores
what is a saturated fat
carbon atoms are joined by single bonds in the hydrocarbon chain
whats the structure of saturated fats
straight chains
why is the structure of a saturated fat good
the straight chains allow them to be packed more tightly so can store energy in a compact from
high melting point
what is an unsaturated fat
carbon double bonds in the hydrocarbon chain
what is the structure of unsaturated fats
from bent chains
what is more than one unsaturated fat called
poly-unsaturated
what is a triglyceride made up of
glycerol and three fatty acids
what is the function of triglycerides
insulation and protection
why is triglycerides more efficient than carbs
more C-H bonds
what are fatty acids
long molecules with polar, hydrophilic end and a non-polar hydrophobic tail
how do triglycerides from
condensation reaction
water is removed and an ester bond is formed
what is a phospholipid
glycerol, 2 fatty acid chains and a phosphate group
what are the main components in a phospholipid
hydrophilic head- negatively charge phosphate group
hydrophobic tails- non polar fatty acids
what is a micelle
droplet spheres with the hydrophilic heads facing the water and the hydrophobic tails facing each other
what is a double layered phospholipid bilayer
traps a compartment of water in the middle seperated from the external water by the hydrophobic sphere
- liposome
what is the structure of cholesterol
a hydrocarbon tail, a central sterol nucleus made of 4 hydrocarbon rings and a hydroxyl group
what is the function of cholesterol
regulate the fluidity of the membranes and strength
what hormones are made from cholesterol
testosterone, oestrogen, vitamin D
what is a glycolipid
combination of carbohydrate and lipid
what is a lipoprotein
combination of lipids and proteins
whats the function of lipoproteins
transport lipids in the blood
what is LDL
low density lipoproteins
function of LDL
delivers fat around the body
delivers fat to endothelial cells of arteries where its deposited as atheroma
how is LDL production increased
diet high in saturated fats
what is HDL
high denisty lipoproteins
what is the function of HDL
removes cholestrol from blood
why is HDL production high
in a diet high in unsaturated fats
how is rate of atherosclerosis reduced
HDL scavenges for excess LDL and returns to liver
