Lipids

two types of fatty acids found in triglycerides

unsaturated and saturated

saturated “fats”

no double bond between carbons

completely saturated with H bonds

unsaturated “fats”

one or more double bond between carbons

why is saturated fats solid at room temperature? (food form)

have straight chains of fatty acid

why is unsaturated fats liquid at room temperature? (food form)

due to double bonds

bends in the fatty acid

monounsaturated fats

unsaturated fat with one double bond

polyunsaturated fats

unsaturated fat with multiple double bonds

why are saturated fats considered unhealthy/ bad

causes an increase in low density lipids (LDL), molecules that carry bad cholesterol

cause heart disease

makes cell membranes rigid and prevents signals from flowing

three types of unsaturated fats

monounsaturated (good to eat)

polyunsaturated (good to eat)

trans unsaturated fats (bad to eat)

trans unsaturated fats

man-made

has been processed and modified

monounsaturated fats benefits

increases high density lipoprotein (HDL), which carries good cholesterol

reduces heart attacks and diabetes

cis/trans unsaturated fats

cis - hydrogens are on same side, causing bend in db

trans - hydrogens are on opposite side of the db, straight

lipids

macromolecule made of mostly carbon, hydrogen, and few oxygen atoms

hydrophobic molecules due to non-polar regions of hydrocarbons which is majority

4 classes of lipids

1. Triglycerides

2. Phospholipids

3. Steroids

4. Waxes

function of triglycerides

long term energy storage because their C-H bonds are rich in energy

insulates and cushions vital organs by surrounding it

provide important components for cell membranes

where are triglycerides stored

adipose cells aka fat cells

how do adipose cells manages energy storage and use

when the body needs energy, adipose cells break down and release, causing it to shrink

excess energy from triglycerides are stored in adipose cells, causing swelling

triglycerides structure

consists of glycerol bonded to 3 fatty acids

glycerol structure

molecule made of a three-carbon chain, each carbon is attached to a hydroxyl group (–OH)

fatty acids structure

hydrocarbons with a carbon bonded to a carboxyl group (COOH) at one end

triglycerides - condensation reaction

bonds the glycerol and fatty acid chain with an ester linkage

3 water molecules are created as byproduct

do lipids have monomers

no true monomer

made up in random combinations

how are trans fats created

manufactured through a hydrogenation process

the process changes the unsaturated cis form to trans by changing the location of the H

phospholipids

major components of cell membranes, makes the lipid bilayer

only two fatty chains

hydrophilic polar heads (fatty acid chains), hydrophobic non-polar tails (phosphate)

function of phospholipid bilayer in a cell

surrounds the cells as a protective boundary

semi-permeable, letting some substances into the cell and not others

what substances are not allowed in the cell

hydrophobic substances because the cell contains water

steriods

lipids with 4 fused carbon rings

functional groups attached will vary depending on the steroid

cholesterol

steroid found in animal cell membranes

produces many hormones (ex. sex hormones)

waxes

type of lipid

diverse structures with long carbon chains

solid at room temperature

waxes in plants

coats surfaces of leaves to prevent water loss

waxes in animals

coats skin, fur, feathers, and exoskeleton to prevent water from entering