module 5 lipids Flashcards
what is the definition of a lipid
organic molecule that dissolves in a non-polar solvent
what is the example shown in video
coconut oil mixed in hexane- dissolved
water with dye did not dissolve in hexane
what is unique about carotenoid molecules
they have vibrant colors
what are some examples of carotenoids in nature
red color of cardinals
yellow of the finch
where does the yellow color of the finch come from
zeaxanthin
where is zeaxanthin come from
bacterium: Pedobacter heparinus
what is the function of the Pedobacter Heparinus
expresses yellow color of zeaxanthin when exposed to sunlight which suggests the protection from UV rays is by using zeaxanthin
what are the five types of lipids discussed in the module
fatty acids triaglycerols phosphoglycerides sphingophospholipids isoprenoid compounds
what does a fatty acid consist of
long chain of carbons with carboxylic acid on one end
how long is a typical fatty acid
8-30 carbon
usually even numbered and typically 12-24 carbon
what does saturated mean when discussing fatty acids
saturated with hydrogen and no double bonds
what is simplified notation system and what does 12:0 notate
an easy way to notate carbons and bonds
12:0 notates 12 carbons and 0 double bonds
what does unsaturated mean
there are 1 or more double bonds
where is a typical bond found in an unsaturated fatty acid
carbon 9-10 and 12
how is an unsaturated fatty acid notated in simplified notation
same as saturated just add delta and number of bonds with superscript where to find the bond
ex: 12:2 delta 9
What is PUFA
polyunsaturated fatty acid- indicating 2 or more double bond present in single chain
what is the name of the numbering system used for PUFA
omega
what is important regarding numbering using omega
start at end of the chain rather than at the carbon( beginning)
where is the double bond frequently found in PUFA regardless of length of chain
3 or 6 from the end of the chain
PUFA require (fill in) because they (fill in)
less energy to digest, contain fewer carbon-carbon bonds to break
what are PUFA known as nutritionally
good fats
what do triacylglycerols do
store energy
why do they store energy
because they are long dense chains of carbon and hydrogen in form of fatty acid chain
what is a function of triacylglcerols
provide insulation by trapping heat
what serves as the backbone for triacylglycerols
glycerol
what is glycerol attached to in triacylglycerols
3 fatty acids via acetyl linkage (-O-CO-)
describe a triacylglycerol that is found in nature
3 fatty acid molecules of different lengths and may contain double bonds or no double bonds- all attached to glycerol
what determines the physical components of a tricylglycerol molecule
number and type of fatty acids
what will cause a triacylglcerol to be more oily
one or more unsaturated chains due to bonds kinking and not packing well with other molecules
what will cause a solid in a triacylglcerol
all fatty acids pack together as they are saturated and there will not be any kinking
what is it called when a lipid is liquid at room temp (25 degrees Cel)
oil
what is it called when a lipid is solid at room temp (25 degrees cel)
solid
describe the structure of a phosphoglyceride
glycerol is backbone with 2 fatty acids attached on 1rst and 2nd carbon and polar group attached to 3rd carbon- choline, serine and others
in a phosphoglyceride what is considered the head and what is the tail
the polar group is considered the head- can interact with water
the long carbon chain is the tail: non-polar and extended
what does the phosphoglyceride molecule allow for
spontaneous form membrane bilayers with tails coming together( form interior) and heads sticking out
what is the main difference in structure between a phosphoglyceride and a sphinogolipid
How are these 2 types of lipids similar
backbone is ceramide
both have 2 fatty acid on chain and 1 polar head group
what is the notation seen distinguishing amide from glycerol and determines type of lipid
HN- amide on 2nd carbon instead of OH for glycerol
What are sphingomyelins, what is the function, how are they described
subclass of sphingolipid form cell membrane but specifically seen in myelin sheath of some neurons polar head with a neutral charge
what is another important function of sphingolipids
they assist in determine blood type
how do sphingolipids assist in determine blood type
polar head is an oligosaccharide that points out and communicates with other cells
Blood types O, A, B have different oligosaccharides attached at the head
how many different functions do sphingolipids have in the cellular membrane
more than 60 identified each with specific functions
what is isoprene
a 5 carbon molecule that is the starting material for many lipids
what are some examples of materials that formsfrom isoprene
vitamins( A and K), cholesterol, cartenoids- yellow dye
what is involved in the preparation of isoprenoid compounds
a 10 step enzymatic process with the isoprene being used to make the carbons including the rings
where in the human body is zeaxanthin found
human eye- protecting from UV
what is vitamin K and what is the function in the body
fat-soluable essential for blood coagulation,
becomes part of protein thrombin which is used form blood clots
Where does the K in vitamin k come from
danish word for Koagulation
what is the important role of cholesterol in the human body
helps maintain fluidity of cell bilayer which is necessary for survival
what is another name for cholesterol and what denotes their structure
sterols
4 rings fused together
How is the definition of lipid different from protein and carbohydrate?
The lipid definition is based on the functional definition of being soluble in a non-polar solvent. Proteins and carbohydrates are based on the structure.
What are three functions of lipids?
Any three of: energy, storage, vitamin, protection, and insulation
How does the omega numbering system differ from the simplified notation?
The simplified notation starts number at the carboxylic acid, while the omega system starts at the opposite end – from the -CH3.
What does unsaturated mean for a fatty acid?
Unsaturated indicates that one or more double bonds are present.
What is the difference between a fat and oil?
An oil is a lipid that is a liquid at room temperature, while fat is a solid at room temperature.
How are phosphoglycerides similar to triacylglycerols? How they different?
Both classes of lipid have glycerol as a backbone structure. Both have fatty acids attached to the glycerol. The difference is that phosphoglycerides have two fatty acids attached to the glycerol and, as the name implies, triacylglycerols have three fatty acids. Phosphoglyceride has a polar head group attached.
What is the primary function of phosphoglycerides mentioned in this module?
forming membrane bilayers
Describe at least two functions of sphingolipids.
They serve as blood group determinants, the structure of membrane bilayers, and in the myelin sheath of neurons.
What is the main difference between phosphoglycerides and sphingolipids?
Sphingolipids have a ceramide backbone structure, whereas the phosphoglycerides have a glycerol structure.
How many carbons and double bonds are in an isoprene unit?
5 carbons and one double bond
What are two functions of isoprenoid compounds
Vitamin production, cholesterol production, and pigment formation
Name three components of a cellular membrane.
phosphoglycerides, cholesterol, sphingolipids, integral proteins, and peripheral proteins
What is an integral protein?
a membrane protein firmly attached to the membrane
