Lipids are essential biomolecules in living organisms, primarily responsible for long-term energy storage. They also serve various other functions such as providing protection, insulation, lubrication, acting as precursors for hormones, and being integral components of cell membranes due to their hydrophobic nature.
a group of biomolecules that play an important role in living organisms
primary function: long-term energy storage
other functions: used for protection, insulation, lubrication, precursors for hormones, key component of cell membranes
insoluble in water (hydrophobic)
Waxes
non-polar (rebel water)
Where is it found
outer surfaces of animals
the protective coating of leaves
Purposes
produced in the ears of some animals to protect the eardrums
bees construct honeycombs from wax
Water repellents
Energy-Storage Substances
Steroids
Fused rings of carbon (4)
each fused ring has different functional groups attached
Cholesterol
Serves as a precursor for the synthesis of other steroids
present in plasma membranes, where it stabilizes the membrane
Cortisone
Vitamin D
Estrogen
Testosterone
have small differences in its functional groups, but large differences in its effect on an organism
Help Contol Metabolism
Helps Immune Functions
Play Roles in Reproduction
Phospholipids
unique properties in regard to water
tend to arrange themselves so that only hydrophilic heads interact with the water environment and the hydrophobic tails crowd inward away from the water
this structure is a major component of plasma membranes of the cell
make a structure called the phospholipid bilayer
can move past each other freely
Phosphate Group
the phosphate head of the molecule is hydrophilic (mixes well with water)
Fatty Acids (2)
fatty acids move about and take an organized structure (micelle)
Phospholipid Bilayer
found in the membrane of the cell
membranes are fluid mosaic
Form Structures for Transportation Throughout the Bloodstream
Critcial for Cell Membranes
Triglycerides
Oils
liquid at room temperature
used by plants for long-term energy storage
Olive oil
Corn oil
Fats
solid at room temperature
used by animals for insulation, protection, and long-term energy storage
Butter
Lard
Subunit Molecules
Fatty Acids (3)
has 3 main parts: the hydrocarbon chain (the chain of carbon and hydrogen atoms), a methyl group at one end, an acid group at the other end
fatty acids move about and take an organized structure (micelle)
Unsaturated
known as cis fatty acids
have one to several double bonds
double bonds result in kinks in fatty acids which can affect the melting point of the fat
Trans Fat
an unsaturated fat where the hydrogen atoms are on opposite sides of the double bond
usually formed during the production of processed foods (also common in partially hydrogenated oils)
associated with cardiovascular disease
Saturated
only single carbon to carbon bonds (this is because the carbon chain is saturated with all the hydrogen atoms it can hold)
