• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

Structure and function of lipids in plants and animals

Extracts from this document...


Structure and function of lipids in plants and animals Lipids are the name given to a mixed group of organic compounds. The elements Hydrogen, Oxygen and Carbon are always found in Lipids. The difference between them and Carbohydrates is that they have a lower proportion of Oxygen in the molecule. Lipids are insoluble in water, but they are soluble in organic solvents, such as ether, acetone, chloroform or benzene. There are several parts in the group of Lipids: o fats and oils, o waxes, o phospholipids, o steroids (like cholesterol, oestrogen and testosterone), and some other related compounds. At room temperature, fats are solids and oils are liquids. Fats and oils are typically found in animals and plants. Fats are of animal origin, while oils tend to be found in plants. Fats and oils are made up of a glycerol (a type of alcohol with a hydroxyl group on each of its three carbons) and three fatty acids (an organic acid). Since there are three fatty acids attached, these are known as triglycerides. A condensation reaction produces a triglyceride and water molecule when the glycerol and three fatty acids react together (see diagram below). ...read more.


They tend to be more characteristic of plants, particularly in oily seeds and fruits, such as castor oil seeds, sunflower seeds and coconuts. Oils can be found in some animals, though, for example the fish liver oils of cod and halibut, and in red fish such as sardines, pilchards, mackerel, salmon, tuna, eels and trout which are referred to as "oily fish". Olive oil is formed when glycerol combines with oleic acid (a type of unsaturated acid). Linolenic and linoleic acids (more unsaturated acids) combined with glycerol are found in linseed oil and in corn oils. They are both examples of "essential fatty acids" which are acids necessary for normal health, but in small quantities and these cannot be made by the body. Waxes are the esters of fatty acids with long chain alcohols such as cetyl alcohol (CH16H33OH). They are rigid and form protective water-resistant coverings on biological surfaces, for example, the cuticle of arthropod exoskeletons, leaf surfaces, fruits, seeds, mammalian skin, fur, feathers. Beeswax is used to construct honeycombs of bees. Lanolin is a waxy substance that coats mammalian hair. Phospholipids are made from glycerol, two fatty acids, and (in place of the third fatty acid) ...read more.


Unsaturated fats are better to have in our diets, because they help to lower our cholesterol levels in the blood. Lipoproteins are the combination of proteins and water soluble lipids. These act as a means of carrying lipids, including cholesterol, around in our blood. There are two main categories of lipoproteins distinguished by how compact/dense they are: o The first type is Low Density Lipoproteins or LDLs. They are bad because they transport cholesterol into the blood system and lay it inside the cells and on the walls of arteries. This increases the cholesterol levels in the blood and therefore increases the risk of coronary heart disease. o The second type is High Density Lipoproteins or HDLs. They are better because they transport cholesterol out of the system into the liver, where it can be excreted. Therefore, they decrease the cholesterol levels and help the body stay healthier. A good source of HDLs is Red (oily) fish. By taking in unsaturated fatty acids known as omega-3 fatty acids, the risk of getting heart disease is lowered, because the cholesterol levels will decrease. Omega-3 fatty acids are found in oily (red) fish and in shellfish, these acids should be included in a good healthy diet, as will keep the body healthier. By Nayan Patel ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our AS and A Level Physical Chemistry section.

Found what you're looking for?

  • Start learning 29% faster today
  • 150,000+ documents available
  • Just £6.99 a month

Not the one? Search for your essay title...
  • Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

See related essaysSee related essays

Related AS and A Level Physical Chemistry essays

  1. Marked by a teacher

    Electrochemical Cells

    5 star(s)

    This means that for the ionic equation: Zn(s) + Cu2+(aq) ? Zn2+(aq) + Cu(s) E0 = 0.342 - (-0.762) = 0.342 + 0.762 = 1.104V Salt Bridge[3] To complete the circuit of the cell, a salt bridge is used. The salt bridge is used to let the electrons flow from one of the solutions to another.

  2. Structure and biological significance of lipids.

    it has a low density so it is useful for aquatic life as a buoyancy aid. The adipose tissue is also quite spongy, so it helps to protect vital organs by absorbing shock. Another function of fats is as a water source, as when respiration occurs using fat + oxygen, water is produced as well as energy and carbon dioxide.

  1. Investigating the Rate of the Reaction between Bromide and Bromate Ions in Acid Solution

    nitrate solution o Error on balance: o Error on volumetric flask: o Total error: 0.27% Making up nickel (II) chloride solution o Error on balance: o Error on volumetric flask: o Total error: 0.31% Making up iron (III) sulphate solution o Error on balance: o Error on volumetric flask: o Total error: 0.22% Making up manganese (II)

  2. The Structure and Function of Lipids.

    A carboxyl (-COOH) group at one end gives the molecule its acidic properties. Most naturally occurring fatty acids contain an even number of carbon atoms in their backbone chains. Although a few with odd numbers are found in all organisms, these make up only a minor fraction of the total.

  1. Antacid Lab. Are name brand antacids better than generic brand antacids to neutralize ...

    The Conservation of Mass can be evident in the Tums mixture. The Tums mixture consisted of one gram of antacid with 30 ml of water with 2400 drops of stomach acid. Since 60 drops is equivalent to 1 ml, 40ml of stomach was used to transform the Tums solution into gastric acid.

  2. Electrochemistry - Inventing Better Batteries

    electrons, the solution in the salt bridge must flow into each solution to balance out any negative or positive charge in the electrolytes. <Bodner Research Web. 2007> Electric Current and Voltage The force motivating electrons to "flow" in a circuit is called voltage.

  1. This assignment is primarily about lipids, triglyceride, unsaturated and saturated fats I will be ...

    There may also be other groups attached to the phosphate. Phospholipids have a polar hydrophilic head and two non-polar hydrophobic tails. They may form a double-layered phospholipids bilayer. This traps a compartment of water in the middle separated from the external water by the hydrophobic sphere.

  2. Alkaloids are the most diverse group of secondary metabolites and over 5000 compounds are ...

    There are few plants which produce a single alkaloid so the main problem is the separation of mixtures. Many alkaloids are basic and occur as salts of 2-hydroxybutane-1, 4-dioic acid (malic acid), or of 1,3,4,5-tetrahydroxycyclohexane (quinic acid).

  • Over 160,000 pieces
    of student written work
  • Annotated by
    experienced teachers
  • Ideas and feedback to
    improve your own work