Macromolecules2 (lipids) lesson3 Flashcards
lipid monomer
fatty acids
lipid functions
structural support for cells, energy storage, and cell signaling
3 main types of lipids
phospholipids, triglycerides, steroids and waxes
Fatty acid definition
Long carbon chains with a carboxyl group (COOH) at the beginning, and methyl group (CH3) at the end.
Saturated fatty acids formula
CH3CH2(n)COOH
Alpha carbon
- carbon connected to the carboxyl group
Beta carbon
- carbon connected to the alpha carbon
Omega carbon
- the last carbon connected to H3 part of the CH3 methyl.
how many carbons in Short chain fatty acids?
fewer than 6 carbons
how many carbons in Medium chain fatty acids-
6-12 carbons
how many carbons in Long chain fatty acids
- 13-21 carbons
how many carbons in Very long fatty acids-
more than 21 carbons
how many carbons in Palmitic acid
16
how many carbons in stearic acid
18
how many carbons in Arachidic acid
20
Saturated- fatty acid definition
fatty acid that includes the maximum amount of hydrogens- each carbon has only single bonds. Example: palmitic acid, stearic acid, arachidic acid.
Unsaturated fatty acid definition
does not include the maximum amount of hydrogen, includes at least one double bond.
atherosclerosis
hardening of the blood vessels as a result of buildup
what increases risk of myocardial infraction?
Saturated fatty acids tend to form solid structures that adhere to blood vessels. This can lead to atherosclerosis (hardening of the blood vessels as a result of buildup) and block the coronary arteries
The number of carbons from the end of the chain until the first double bond is defined as
Omega ω
Humans can only produce fatty acids with an omega….
higher than 7
essential fatty acids
fatty acids with an omega lower than 7
must be obtained through diet.
non essential. fatty acids
Fatty acids that can be synthesized by the human organism
TAG (Triacyl Glycerol)
Glycerol molecule bonded to three fatty acid molecules by an ester bond (-o-). Found in the adipose tissue- it is what people refer to as fat.
Formed by a condensation reaction - H2O removed.
TAG (Triacyl Glycerol) uses what bond to bind Glycerol to three fatty acid molecules?
ester bond
TAG (Triacyl Glycerol) Functions
- Energy storage - adipose tissue is a natural fat providing energy up to 6 to 10 weeks of starvation.
- Temperature regulation - adipose tissue insulates the body.
- Protection - adipose tissue cushions the internal organs.
Phospholipids:
A class of lipids composed of glycerol connected with two fatty acids, and a phosphate group connected to an additional organic molecule, forming the head.
the head of a Phospholipid is
polar and therefore hydrophilic
The tail of a Phospholipid is
nonpolar and therefore hydrophobic.
The organic molecule connected to the phosphate in a phospholipid group can be
choline, , serine or ethanolamine
amphipathic molecule-
one side is hydrophobic and the other hydrophilic.
phospholipid Functions
- Compose cellular membranes and organelles
- Store fatty acids
- Compose part of lipoproteins- LDL, HDL, VLDL, Chylomicrons
- The surfactant of the lungs is composed of phospholipids
Cholesterol
A molecule composed of a chain of rigid sterol rings.
It does not dissolve in the blood, therefore it travels connected to carrier lipoproteins;
LDL
Low Density Lipoproteins
transport cholesterol from the liver to body tissues
“bad cholesterol”
HDL
High Density Lipoproteins
collect cholesterol from the body tissues
and transports it back it back to the liver
“good cholesterol”
Cholesterol Functions
- Serves as a precursor to steroid hormones
- Used In the formation of the cell membrane- accounts for its fluidity and rigidity
- Precursor of bile (מיץ מרה)
- Precursor of vitamin D
- Part of a fatty layer on neurons called the myelin sheet
hypercholesterolemia
High levels of cholesterol in the blood
forms of lipoproteins related to cholesterol in the blood
Very low density lipoprotein-VLDL
Intermediate density lipoprotein- IDL
High density lipoprotein- HDL
Low density lipoprotein- LDL
