function
the actions of lipids inside the cell
Used to build structure in and around cell membranes
the monomer of a lipid
Glycerol and fatty acids
The structure phospholipids form when placed in water
a bilayer
Cholesterol contains this kind of carbon structure, shared by all steroids
four fused rings
The difference between an unsaturated and saturated fatty acid
The presence of double bonds in unsaturated fat
the action of lipids inside the general organism
Primarily used to provide energy and are used for structural supports as building blocks. Fats store energy, insulate the body, and serve as a cushion for vital organs
The different polymers of a lipid
Triglycerides, phospholipids, and cholesterol/steroids/waxes
Phospholipids form bilayers when in water (why)
because their hydrophobic tails face inward, away from water, and hydrophilic heads face outward
Cholesterol acts as this in animal cell membranes, helping with fluidity
A fluidity buffer
All steroids share this molecular backbone structure
four fused carbon rings (three 6-membered and one 5-membered)
how lipids interact with water
Non-polar hydrophobic, but phospholipids have a hydrophilic head
The elements that make up a lipid
C,H, and O- a triglyceride (glycerol) with 3 fatty acid (hydrocarbon) chains
Phospholipids are a key component in this major cellular structure
cell membrane
In cold temperatures, cholesterol prevents membranes from becoming too this
Rigid/solid
Phospholipids can form these spherical vesicles used in transport or lab models of membranes
Liposomes
why lipids are needed for other macromolecules
they form the lipid blayer- protecting the cell and controlling what can enter the cell. They also help cell signaling, protein binding, and membrane fusion, contributing to overall cell health and function.
The process by which polymers are built up and broken down
Dehydration reaction
how the amphipathic (having polarity and non-polarity) nature of phospholipids contribute to selective permeability
by allowing small nonpolar molecules to pass through while blocking large or charged substances
Cholesterol is synthesized primarily in this organ
The liver
Steroid hormones exert their effects by binding to these types of intracellular proteins
nuclear receptors (or intracellular hormone receptors)
Some lipids function as these chemical messengers in the body
Steroid hormones
The name of the types of bonds that are used to link monomers
Ester linkage (between glycerol and fatty acid)
Phospholipids differ from triglycerides in this key structural way
the substitution of one fatty acid with a phosphate group (attached to a polar head group)
Cholesterol is a precursor for this vitamin, produced in skin exposed to sunlight
Vitamin d
The presence of cholesterol in lipid rafts contributes to these two critical membrane properties
structural stability and compartmentalization of signaling pathways