9: Lipids - Fatty Acids

Polyunsaturated Fatty Acids have double bonds occurring every _____ Carbon and are _____________.

3rd, not conjugated

Fatty Acid have between _________ carbons and almost all have an _____ number of carbons. Most common species are _____ and ______. Most natural fatty acids are ___________.

4-36, even, C16 and C18, unbranched

Fats provide ______ more metabolic energy of equal weighted hydrated glycogen.

6x

Storage lipids make up _____% of the dry mass of the adipocyte

80

First double bond in unsaturated fats commonly occur between ______ and _____.

C9, C10

In vertebrates, ___________ store triacylglycerols.

adipocytes (fat cells)

Fatty Acids are:

carboxylic acids with long-chain hydrophobic side groups

Hydrogenation:

cis fats have some double bonds eliminated, converting some of other cis double in molecule to trans double bonds

Unsaturated Fatty Acids _______ double bonds.

contain

The presence of double bonds in fatty acids ________ melting points.

decrease

Unsaturated Fatty Acids melting point _________ with _________________________________.

decreases, degree of saturation

Fatty acid solubility in water ________________ as the chain length _______________.

decreases, increases

How are lipids differentiated from sugars?

fatty acids carry more energy per carbon because they are more reduced. fatty acids carry less water per gram because they are nonpolar

Lipids 3 Biological Functions

form membranes, serve as energy stores, intra and intercellular signaling

Saturated Fatty Acids ________ double bonds.

have no

Saturated Fatty Acids have a ______ melting point, ________ pack together, a ______ structure, and have _______ van der Waals interactions, and are often _________________.

high, efficiently, flexible, increased

Cis fats can be converted to trans fats by:

hydrogenation

Triacylglycerol in Adipocytes undergoes _______________ to become converted into ______________.

hydrolysis by lipases, fatty acids

A longer length of tail in fatty acids __________ melting points.

increase

Trans Fats are preferred by food industry because:

increased stability = longer shelf life

Partial Hydrogenation Side Effects:

increases risk of cardiovascular disease, increases cholesterol in blood

Saturated Fatty Acids melting point __________ with _________________________________.

increases, molecular mass

Lipids are separated by:

lipids that do not contain fatty acids (cholesterol) and lipids that contain fatty acids (complex lipids)

Unsaturated Fatty Acids have a _____ melting point, ________ pack together, have a ______ conformation, a _______ degree ______ bend, and have _______ van der Waals interactions, and are often _________________.

low, inefficiently, cis, 30, rigid, reduced, polyunsaturated

Triacylglycerols make up __________ of fatty acids found in biological systems. They are ______ soluble in water than fatty acids due to __________________. They are ______ dense than water (_______). They are the ________________________ (_________).

majority, less, less, (float), primary storage form of lipids, (body fat)

Trans fat are more stable than cis fats because:

melting point increased due to less double bonds

Triaclglycerols are found as _______, ___________________ in the _______________.

microscopic, oily droplets, cytosol

Triacylglycerols are efficient at energy storage because (2):

nonpolar and stored in anhydrous form as compared to glycogen which binds 2x its weight of water

Lipid Structure

not polymeric, great variety, hydrophobic, mostly insoluble in water

Fatty Acid predominate residues:

palmitic, oleic, linoleic, and stearic acids

Hydrogenation removes ___________ of molecule caused by ______________. Allows structure to be more __________ and some of the additional cis bonds are converted to __________.

rigidity, cis double bonds. flexible, trans

Glucose and glycogen are for _________-term energy, ______ delivery. Fats are for _______-term energy needs, ___________________ and ______ delivery.

short, quick. long, good storage, slow

Fats are ________ at room temperature and oils are ________.

solid, liquid

Partial Hydrogenation:

some cis bonds -> trans bonds

Lipids that Contain Fatty Acids can be further separated into:

storage lipids and membrane lipids

Lipids are classified based on:

structure and function

It takes ___________ energy to disrupt disordered packing on unsaturated fatty acids. (Unsaturated cis fatty acids have a _______ melting point).

thermal, (lower)

Triacylglycerols are efficient at energy storage because (1):

they are less oxidized than carbohydrates/proteins and yield more energy/mass on complete oxidation