LIPIDS 1

58問 • 1年前

問題一覧

Lipids consist of fats, oils, hormones, and certain components of membranes that are grouped together because of their _______

hydrophobic interactions

The lipids are essential constituents of the diet because of their ________

high energy value

These are also essential for the fat-soluble vitamins and the essential fatty acids found with the fat of the natural foodstuffs.

Lipids

Fats combined with proteins (______) are essential constituents of the _______ of the cell.

lipoproteins; cell membranes and mitochondria

occur naturally in living beings like plants, animals, and microorganisms that form various components like cell membranes, hormones, and energy storage molecules.

Lipids

Lipids exist in either __________ or ________ and are colorless, odorless, and tasteless.

liquid or non-crystalline solids at room temperatures

Lipids are composed of ______

fatty acids and glycerol

are a group of diverse macromolecules consisting of fatty acids and their derivatives that are insoluble in water but soluble in organic solvents.

Lipids

Lipids may be either _____ or _______ at room temperature.

liquids or non-crystalline solids

are colorless, odorless, and tasteless.

Pure fats and oils

Lipids are ______ organic molecules

energy-rich

Lipids are _______ in water

Insoluble

➤ Lipids are soluble in organic solvents like _______

alcohol, chloroform, acetone, benzene, etc.

Lipids has ionic charges

False

Solid triglycerols (Fats) have high proportions of ________

saturated fatty acids.

Liquid triglycerols (Oils) have high proportions of ________

unsaturated fatty acids.

Triglycerols like any other esters react with water to form their carboxylic acid and alcohol- a process known as ________

hydrolysis

Triacylglycerols may be hydrolyzed by several procedures, the most common of which utilizes alkali or enzymes called lipases. ________is termed saponification because one of the products of the hydrolysis is a _____, generally sodium or potassium salts of fatty acids.

Alkaline hydrolysis; soap

The carbon-carbon double bonds in unsaturated fatty acids can be hydrogenated by reacting with _______ to produce ________.

hydrogen; saturated fatty acids.

Unsaturated fatty acids, whether they are free or combined as esters in fats and oils, react with _______ by addition at the double bond(s). The reaction results in the ______ of the halogen solution.

halogens; decolorization

The term rancid is applied to any fat or oil that develops a _______. ______ are responsible for causing rancidity. ______ occurs in triacylglycerols containing unsaturated fatty acids.

disagreeable odor; Hydrolysis and oxidation reactions ; Oxidative rancidity

Lipids are made of the elements ______ but have a much lower proportion of _____ than other molecules such as carbohydrates.

Carbon, Hydrogen and Oxygen; water

Unlike polysaccharides and proteins, lipids are not ________-they lack a ________

polymers; repeating monomeric unit.

Lipids are made from two molecules:

Glycerol and Fatty Acids.

A ________ is made up of three carbon atoms with a hydroxyl group attached to it and hydrogen atoms occupying the remaining positions.

glycerol molecule

Fatty acids consist of an _______ at one end of the molecule and a _______, which is usually denoted by the letter 'R',

acid group; hydrocarbon chain

A fatty acid is saturated if every possible bond is made with a _______, such that there exist ______

Hydrogen atom; no C=C bonds.

Unsaturated fatty acids, on the other hand, do _____ . ______ fatty acids have one C=C bond, and ______ have more than one C=C bond.

contain C=C bonds; Monounsaturated; polyunsaturated

Lipids can be classified according to their ______ and according to _______

hydrolysis products; similarities in their molecular structures

Fats and oils which yield _______ upon hydrolysis.

fatty acids and glycerol

Waxes, which yield ________ upon hydrolysis.

fatty acids and long-chain alcohols

Fats and Oils—Both types of compounds are called ________ because they are esters composed of three fatty acids joined to glycerol, trihydroxy alcohol.

triacylglycerols

The differencebetween fats and oils is on the basis of their physical states at room temperature. It is customary to call a lipid a ____ if it is solid at 25°C, and ____ if it is a liquid at the same temperature.

fat; oil

These differences in melting points (of fats and oil) reflect differences in the degree of ______ of the constituent fatty acids.

unsaturation

is an ester of long-chain alcohol (usually mono-hydroxy) and a fatty acid.

Wax

The acids and alcohols normally found in waxes have chains of the order of

12-34 carbon atoms

________, which yield fatty acids, glycerol, amino alcohol sphingosine, phosphoric acid and nitrogen-containing alcohol upon hydrolysis. They may be ________ depending upon the alcohol group present (glycerol or sphingosine).

Phospholipids; glycerophospholipids or sphingophospholipid

, which yield fatty acids, sphingosine or glycerol, and a carbohydrate upon hydrolysis. They may also be ______ depending upon the alcohol group present (glycerol or sphingosine).

Glycolipids; glyceroglycolipids or sphingoglycolipid

Hydrolysis product of simple and compound lipids is called ______. They include fatty acid, glycerol, sphingosine and steroid derivatives.

derived lipids

are phenanthrene structures that are quite different from lipids made up of fatty acids.

Steroid derivatives

3 major subclasses of Lipids

simple, compound, derived

The most important and frequently occurring alcohol found in lipids is ______.

glycerol

is a small organic molecule consisting of three hydroxyls (OH-) groups.

Glycerol

Glycerol makes up _____which are esters of fatty acids and glycerol and similar alcohols.

simple lipids

The alcohol might be glycerol or other long-chain alcohol. The long-chain alcohols are mostly ______

mono-hydroxy with a single OH group.

The esters of fatty acids are formed after the _________ between the fatty acids and the alcohol molecules.

dehydration reaction

are a type of lipid which is an ester of three fatty acids with glycerol.

Triglycerides

are the main constituents of body fat in humans, other vertebrates, and vegetable fats.

Triglycerides

Triglycerides are tri-esters where three fatty acid molecules are bound to a single glycerol molecule by

covalent ester bonds

The three fatty acids involved in the condensation reaction are usually different, and their chain length also differs from one another.

True

In naturally occurring triglycerides, the fatty acid chains mostly contain

16, 18, or 20 carbon atoms.

Even-numbered carbon atoms present in animals and plants indicating the pathway of their biosynthesis from

two-carbon acetyl CoA.

Simple triglycerides might also have identical fatty acids forming _______

homotriglycerides

The charges in triglycerides are evenly distributed around the molecules, which prevents the _______ with water molecules, making them insoluble in water

formation of hydrogen bonds

are important macromolecules as they store most of the energy in the body.

Triglycerides

Triglycerides are stored in ____ which are then released into the _____ by the action of different hormones whenever necessary.

fat cells; bloodstream

The fat stored in the body forms a layer of ______ beneath the skin, which helps to maintain the

insulation; body temperature.

Triglycerides also aid in the absorption and transport of _________ in the body.

fat-soluble vitamins

CH 1

OBILLO, MIKAELA T. · 78問 · 1年前

CH 1