What Additional Molecule Is Produced When Fatty Acids Are Bonded to Glycerol to Make a Triglyceride?

Summary

• Lipids are a heterogeneous group of compounds that are soluble in solvents like alcohol and benzene just insoluble in water
• They are the big source of energy within the body
• They are the edifice blocks of many higher molecular weights compounds
• Lipids are associated with certain disorders such every bit atherosclerosis and obesity
• One molecule of glycerol and three molecules of fatty acid come together via a condensation reaction to form a triglyceride
• Triglycerides and phospholipids are two groups of lipids
• A condensation reaction (removal of water) between a glycerol molecule and fat acrid forms an ester bond
• Hydrolysis, addition of a h2o molecule, of a triglyceride grade fatty acids and glycerol.
• A fatty acid that has more than one double bond (=) is chosen a polyunsaturated fatty acid and if one double bail is present they are termed monounsaturated fatty acid
• A phospholipoid construction is where one fat acid grouping of a triglyceride is substituted with a phosphate containing group
• Phospholipids are polar molecules where they accept a hydrophilic phosphate 'head' and a hydrophobic 'tail' of 2 fat acids making them
• In aqueous solution phospholipid molecules are the main component of the jail cell membrane in fauna and plant cells and form a lipid bilayer of cell surface membranes

What are lipids

Lipids are the class of organic compounds which means they are carbon containing compounds. They are hydrophobic (water-fearing) in nature. They are more often than not soluble in solvents such every bit alcohol, ethers and chloroform just insoluble in water. Lipids are the various group of compound that are made up of fatty acids and their derivates. They mostly include fats, oils, waxes, hormones and sure components of jail cell membrane.

Formation of a bones lipid

The basic construction of a lipid comprises of a glycerol and three fatty acids shown in Figure i. When a molecule of 1 glycerol molecule and iii fatty acid molecules (R-COOH) bring together together, a condensation reaction takes place (ester bond formation) where three h2o molecules are removed and a bones lipid is formed which is chosen triglyceride. The formation of a triglyceride is illustrated in Figure 1. In triglycerides the glycerol molecule (Effigy 2) is the same but there are different forms of oils and fats which are due to the different types of attached fatty acids. The R group of the fatty acrid group may be either polyunsaturated or saturated.

Figure 1 illustrates the formation of a triglyceride

Glycerol

Glycerol's are alcohols with three carbons and three hydroxyl (OH) molecules attached with five hydrogen molecules (chemic structure shown beneath). In a triglyceride structure glycerol's are the backbone attached with three fatty acids. The bond between fat acid and glycerol is called ester bail.

Effigy two shows chemical structure of glycerol

Functions of lipids

Lipids mainly include fats, oils, certain hormones, steroids and some complex molecules which makes them have a variety of functions some of which are equally follows:

• They are the source of energy
• They can be hands stored in torso
• The insulate the body temperature
• They protect many internal organs as a padding agent
• They are an important component of living jail cell; every bit the prison cell membrane is made upwards of a phospholipid bilayer
• Some lipids like steroids and hormones serve as chemical messengers between cells tissues and organs

Exam for lipids

The exam for lipids is known as the emulsion examination. The process follows:

Method:

• Add together 2cm3 drops of sample being tested with 5cm3 of ethanol
• shake vigorously to dissolve the solution
• Add an equal corporeality of water

Results:

• If a lipid is present in the solution, a cloudy-white emulsion is observed

Theory:

• Ethanol emulsifies fats
• When water is added, an emulsion of any tiny aerosol refract calorie-free to brand the appearance look cloudy

Classification of lipids

There is no single internationally accustomed system of classification of lipids. The effigy below is one of the more accepted scheme of classification for lipids (Figure iii):

Figure 3 schematic of the classification of lipids

Classification of lipids

Lipids are basically classified into iii groups

• Uncomplicated lipids
• Chemical compound lipids
• Derived lipids

Uncomplicated lipids

These are the esters of fatty acids with glycerol'southward
Fatty acids + glycerol'southward ——- Lipids

They are farther subdivided into 2 groups
a) Triglyceride b) Waxes

a) Triglycerides

Triglycerides are the combinations of fat acids with glycerol's (Figure i)
Oils are the liquid triglycerides at room temperature
Fats are solid triglycerides at room temperature
Oils and fats are most arable lipids plant in nature. Information technology is the all-time kind of reserve food material in humans and source of energy. They also act every bit a insulator for body rut and also protect internal organs of the body as a padding material
A triglyceride molecule is formed by joining of one molecule of glycerol to three fatty acids combined with glycerol. Each fatty acid is joined and combined with the glycerol forming an ester bond in three condensation reaction.
Hydrolysis causes the breakup of the triglyceride and produces glycerol and three fatty acids.
Triglycerides have key roles in respiration and energy storage due to its insolubility and its high carbon to hydrogen ratio
Triglycerides have depression mass to volume ratio making them good molecules for storage
They practise non affect water potential of cells since they are large in nature and insoluble in water

b) Waxes

These are the esters of fatty acids with alcohol (with college molecular weight) other than glycerol. Waxes are present all over in nature. Many plant leaves take waxy coating which protects them from aridity. These are as well obtained from animal sources of which most common are bees wax and spermaceti. Spermaceti is obtained from sperms of whales and is more often than not used in cosmetics and pharmaceuticals.

Compound lipids

These are the esters' of fatty acids with alcohol and another additional groups because of which they accept many types most common are as follows:

a) Phospholipid

• They are found in animal tissues plasma membranes of animal and plant cell
• Phospholipids are the class of lipids which are made upward of esters of fatty acid and glycerol'south with phosphoric acrid and nitrogen base of operations
• They class the major part of the cell membrane
• They form the lipid bilayer because of their amphiphilic character. The phospholipid molecules compose of 2 ('h2o-repelling') hydrophobic fatty acid "tail" and the hydrophilic ('water-loving') phosphate group "caput" (Figure 4)
• Phospholipids are similar to lipids where a fatty acid molecule is replaced past a phosphate molecule. The fat acids are hydrophobic and repel water whereas, phosphate molecules attract water and are known to be hydrophilic

Figure 4 schematic the structure of a phospholipid

b) Plasmogens

They occur in the centre and encephalon muscles

c) Lipositol

These are present in combination with phytic acid in brain, middle, kidneys and plant tissues

d) Sphingomyelin

These are the source of phosphoric acid in body tissues as well present in nervous system and cherry-red blood cells

Derived lipids – Fatty acids

Fatty acids are comprised of hydrocarbon chains terminating with carboxylic group (-COOH). There are around seventy fatty acids. These are obtained from the hydrolysis of natural fats and oils. The hydrocarbon chain in fatty acid may contain single or double bail.

Those fatty acids that accept single bail between carbon hydrogen and no double bonds they are called saturated fatty acids; every bit all the carbon atoms are attached with the maximum possible number of hydrogen atoms. Those fatty acids that have double bail (C=C) betwixt carbon hydrogen are called unsaturated fatty acids (Figure five).

• These are the hydrolytic products of compound lipids
• These are present in animal and establish food
• They are obtained from hydrolysis of fats
• They are hydrocarbons derivatives

Effigy v schematic illustrating different chemic structures of saturated, monounsaturated and unsaturated fatty acids

Physical backdrop of lipids

• Mostly fats and oils are colorless, odorless where whatsoever color is nowadays due to some external group attached
• They accept less than 1 specific gravity
• They have low melting points
• They are poor conductors of estrus and electricity
• When agitated with h2o in the presence of lather they class emulsions

Chemic properties of lipids

Hydrolysis

Information technology takes place by heating a triglyceride with water at higher temperature and pressure in the presence of an enzyme called lipase which results in the germination of fatty acid and glycerol.

Sponification

When fats are boiled with strong a alkaline solution it decomposes into glycerol's and table salt of fatty acids shown in the figure below:

Rancidity

Information technology is the unpleasant smell and taste that develop past fats upon crumbling due to hydrolysis of component glycerides of fats into fat acrid and glycerol.

Cell membrane

Phospholipids grade cell membrane because of the arrangements of the hydrophilic phosphate group head and hydrophobic fatty acid tail. The phospholipids lined upwardly to each other with tails inside and head facing outside due to which a double layer is formed called lipid bilayer.

Figure 6 schematic illustrating the phospholipid bilayer

Functions of phospholipids

1. Phospholipids act as a barrier in cell membrane to protect cell
2. Phospholipids in combination with proteins brand the cell to exist selectively permeable
3. Phospholipids are important components of cell surface membranes where they form a bilayer arrangement which allows lipid-soluble substances to be crossed easily Phospholipids take function in assembling of lipoprotein
4. The bilayer organisation relates back to the structure of the phospholipid. Since both inside the cell and outside the cell consist of water, the phospholipids in the cell surface membrane form a double layer.
5. Where the hydrophilic ('water-loving') heads of the phospholipids point into the watery environment outside the membrane or inside the cell. While, the hydrophobic tails point in the middle of the membrane. This forms a hydrophobic core within the cell membrane (Figure half dozen).
6. Phospholipids also work every bit a emulsifier in body in wetting surfaces like joints and other parts of body.

References:

[1]. https://alevelbiology.co.uk/notes/lipids/
[2]. https://www.britannica.com/science/lipid
[3]. https://www.medicinenet.com/script/primary/art.asp?articlekey=4168
[4]. https://byjus.com/biology/lipids/
[v]. https://www.researchgate.net/publication/294873626_Producing_pork_to_meet_modern_consumer_demands/figures?lo=1
[half-dozen]. https://nsb.wikidot.com/c-ix-5-v-i
[7]. https://openstax.org/books/biological science-2e/pages/3-iii-lipids

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Source: https://alevelbiology.co.uk/notes/lipids-triglyceride-and-phospholipid-synthesis/

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