Biological Molecules -NDB

Biological Molecules

by Nilanjan De

​Biological Molecules

• ​Biological molecules are complex chemicals

• Produced by cells and living organisms​

• Biomolecules have a wide range of sizes and structures and are needed by living organisms for metabolism.​

• ​These molecules can be very large often constructed of repeating sub-units.

​

Major ​Elements that make up Biomolecules

• ​Carbon

• ​Hydrogen

• Oxygen​

• ​Nitrogen

Multiple Choice

Which of following is NOT a major element involved in making biomolecules?

• Calcium

• Nitrogen

• Hydrogen

• Carbon

​Types of Biological Molecules

​

• ​Lipids

• ​Carbohydrates

• ​Proteins

• ​Nucleic Acids

​What do they do?

• ​LIPIDS

  • Cell membrane structure, energy storage

• CARBOHYDRATES​

  • ​Source of energy, structural component

• ​PROTEINS

  • ​Building block, reactions, repair

• ​NUCLEIC ACIDS

  • ​Genetic material

​Some key terms -

Multiple Select

Which of the following statements correctly describe biological molecules? Chooses all the correct statements.

• They all contains carbon and are described as organic molecules.

• There are four major types namely carbohydrates, fats, proteins and nucleic acid.

• It is produced by living organisms.

• All biological molecules are of the same structure.

Multiple Choice

Select the type of molecule that is used as energy store molecules

• potein

• lipid

• carbohydrate

• nucleic acid

Multiple Choice

Select the type of molecule that stores genetic information

• potein

• lipid

• carbohydrate

• nucleic acid

​Water

• ​Water is important for all living organisms as many substances are able to dissolve in it (it is a solvent).

• ​Water is known as a polar molecule

Multiple Choice

Large food molecules are composed from smaller molecules chemically bonded

together.

• True

• False

Role Within Organisms

• ​Dissolved substances can be easily transported around organisms – eg xylem and phloem of plants and dissolved food molecules in the blood

• ​Digested food molecules are in the alimentary canal but need to be moved to cells all over the body – without water as a solvent this would not be able to happen

• ​Toxic substances such as urea and substances in excess of requirements such as salts can dissolve in water which makes them easy to remove from the body in urine

• Water is also an important part of the cytoplasm and plays a role in ensuring metabolic reactions can happen as necessary in cells​

​

​Lipids

• a.k.a. Fat and Oils​

• Fats and oils are made up of the elements carbon, hydrogen and oxygen.

• ​A molecule of fat (or oil) is made up of three molecules of an organic acid, called a fatty acid, combined with one molecule of glycerol.

• ​There are different types of fatty acid and these can form different fats with different properties.

• Fats are used for energy storage and thermal insulation in the body.​

• ​

​Lipid - Structure

• ​One Glycerol molecule

• ​Three fatty acid molecules

• ​Joined by Ester bond formed between 'OH' group of glycerol and 'COOH' group of fatty acid.

Multiple Choice

How many fatty acids bind to glycerol?

• 2

• 3

• 6

• 1

Multiple Choice

Name the bond formed between a glycerol molecule and the fatty acids

• Glycosidic

• Peptide

• Ester

• Ether

​Lipid

​Ester Bond