Lipids: Triglycerides, Phospholipids, and Sterols - Fundamentals of Nut Lecture 6 & 7

All fatty acids have the same basic structure - a chain of carbon and hudrogen atoms with an ________ group (COOH) at one end and a _______ group (CH3) at the other end.

acid; methyl

Lipids are soluble in

alcohol, ether, choroform and other fat solvents

Gallbladder releases _____ into the small intestine.

bile

Ester

bond between alcohol and acid

Most fat arrives intact at the stomach, where it is _________ and broken into ______.

broken; droplets

Chemist use a shorthand notation to describe fatty-acids. The first number indicates the number of _________ ______, the second the number of _________ ________. For example the notation for stearic acid is 18:0

carbon atom; double bonds

The four characteristics of fatty acids are __________, saturation, ___________, essentiality

chain length; melting point

Fatty acids are basically........

chains of carbon atoms

In nature, most double bonds are _____, meaning that the hydrogens next the other double bonds are on the same side of the carbon chain.

cis

To make a triglyceride, a series of _________, reactions combine a hydrogen atom (H) from the glycerol and a hydroxyl (OH) group from a fatty acid, forming a molecule of water and leaving a bond between the two molecules.

condensation

After ___________, more fat is exposed to the __________, making fat digestion more efficient.

emulsification; enzymes

Bile's _________ action converts large fat globules into small droplets that _______ each other.

emulsifying; repel

The bonds formed by condensation between the alcohol from glycerol and acid from fatty acid creates _______ bonds.

ester

The degree of unsaturation influences the __________ of fats at room temperature.

firmness

Every trigleceride contains one molecule of ___________ and three ____________

glycerol; fatty acids

Exposure to _______ and ______ can also speed up rancididty.

heat; light

When fats enter the mouth, salivary glands release ________, an enzyme that digests some triglycerides.

lingual lipase

Omega-6 fatty acids or ________ acid has how many carbon double bonds?

linoleic; 2

Omega-3 fatty acids or _________ acid has how many carbon double bonds?

linolenic; 3

Omega-3 (________) and omega-6 (_________) are the primary member of a family of longer-chain fatty acids that help regulate __________, _____________, and other body functions important to health.

linolenic; linoleic; blood pressure; blood clotting

Polyunsaturated fats do not pack tightly together and are typically __________ at room temperature.

liquid

Unsaturated fatty acids may have one or more points of unsaturation - that is, they may be ___________ or _____________.

monounsaturated; polyunsaturated

Of special importance in nutrition are the polyunsaturated fatty acids knows as _________ fatty acids and ______________ fatty acids.

omega-3; omega-6

The 18-carbon polyunsaturated fatty acids are linolenic (________) and linoleic acid (_________). Both are essential fatty acids that the body CANNOT make.

omega-3; omega-6

Monounsaturated fatty acids tend to belong to the ____________ group, with their closes (and only) double bond ________ carbons away from the methyl (CH3) end.

omega-9, nine

Monounsaturated fatty acid (MS)

one carbon-carbon double bond (one carbon not saturated with hydrogens)

Fatty acid

organic compound composed of a carbon chain with hydrogens attached and an acid group (COOH) at one end and a methyl group (CH3) at the other end.

The _________ of fats produces a variety of compounds that smell and taste rancid.

oxidation

Lipid-digesting enzymes from the _______ break triglycerides into monoglycerides and fatty acids.

pancreas

Vegetable oil, corn oil, and olive oil are examples of _________ fats.

polyunsaturated

Butter and lard are examples of _________ fats.

saturated

Fatty acids may be __________ or __________.

saturated; unsaturated

The four characteristics of fatty acids are chain length, __________, melting point, ___________

saturation; essentiality

Generally, the ________ the carbon chain, the softer the fat is at room temperature.

shorter

Some oils - notably, coca butter, palm oil, palm kernel oil, and conut oil - are saturated; they are firmer than most vegetable oils because of their saturation , but softer than most animal fats because of their........

shorter carbon chains.

When fat enters the ________ ________, the gallbladder excretes bile. Bile has an affinity for both ________ and ________, so it can bring ________ into the _________.

small intestine; fat; water; fat; water

Saturated fats are packed tightly together making them ________ at room temperature.

solid

In the __________, the fat and watery GI juices tend to separate. The __________ in the GI juices cant get at the fat.

stomach; enzymes

Omega

the last letter of the Greek alphabet, used by chemists to refer to the position of the closest double bond to the methyl (CH3) end of the fatty acid.

oxidation

the process of a substance combining with oxygen resulting in the loss of electrons.

Saponification

the reaction between a fat and a strong base to produce glycerol and the salt of a fatty acid (soap)

A _____-fatty acid is one that the hydrogens next to the carbon double bonds are on opposite sides of the carbon chain.

trans

Hydrogenation produces ________ -fatty acids.

trans

Polyunsaturated (PS)

two or more carbon bonds not saturated and therefore have several carbon-carbon double bonds.

Tryglcerides compose ______% of the types of lipids found in foods.

95

Long chain fatty acids are between _____ and ______ carbons long.

12; 22

Chemical ratio for stearic acid

18:0 (saturated)

Fatty acids may be ____ to _____ (even number of carbons) long, the ____ -carbon ones being the most common in foods and especially noteworthy in nutrition.

4; 24; 18

Short length fatty acids are less than ______ carbons long

6

Medium chain fatty acids are between ______ and _______ carbons long.

6; 10

______ from the gallbladder breaks fat into smaller droplets.

Bile

________ contracts due to secretion of _______ and ______ from the duodenal mucosal cells.

Gallbladder; CCK; secretin

_______ _______, an enzyme in the stomach, digests some triglycerides.

Gastric lipase

_________ __________ enzymes from the pancreas break dietary cholesterol esters and phospholipds into their components.

Lipid-digesting

__________ transport lipid digestion products to teh enterocytes of the small intestine for absorption.

Micelles

Does a large amount of fat digestion occur in the mouth?

No, little lipid digestion occurs in the mouth.

_______ fats spoil most readly because their ______ bonds are unstable.

Polyunsaturated; double

________ fats are most resistant to oxidation and thus least likely to become rancid.

Saturated

Hydrogenation

a chemical process by which hydrogens are added to mmonounsaturated o poyunsaturated fatty acids to reduce the number of double bonds, making the fats more saturated (solid) and more resistant to oxidation.

Lipids

a family of compounds that includes triglycerides, phospholipids, and sterols. They are characterized by their INSOLUBILITY in water.

Unsaturated fat

a fat composed of triglycerides in which most of the fatty acids are unsaturated.

Unsaturated fatty acid

a fatty acid that lacks hydrogen atoms and has at least one double bond between carbons (includes mono- and poly-).

Saturated fatty acid

a fatty acid which is fuly loaded with all its hydrogen atoms and contains only single bonds between its carbon atoms.