Monomers & Polymers
Biology: Cambridge International A Level, topic 2.2.1
Monomers and Polymers
There is a huge variety of species on earth. Despite this incredible diversity, all living organisms are made up of similar biological molecules called monomers.
Monomers
- Monomers are the single subunits, or building blocks, of life.
- E.g. Amino acids, nucleotides and monosaccharides.
Polymers
- Polymers are formed by combining monomers using covalent bonds.
- Polymers are complex molecules.
- E.g. Protein, DNA, starch.
Condensation Reactions
Condensation is the formation of larger, biological molecules (polymers) from smaller molecules (monomers). The byproduct of condensation reactions is water.
Formation
- Smaller, biological molecules (e.g. sugars) in an organism's cells can form larger, molecules (e.g. carbohydrates) that can be used around the body.
- These biological molecules are important to allow the organism to survive.
Condensation
- Condensation is the reaction that forms large, biological molecules.
- The reaction releases water and bonds the smaller components together into larger molecules.
Products of condensation
- Condensation of amino acids produces proteins.
- Condensation of two monosaccharides produces disaccharides.
- Many disaccharides form polysaccharides.
- Condensation of fatty acids and monoglycerides produces lipids.
Hydrolysis Reactions
Hydrolysis is the break down of large, biological molecules into smaller molecules. The smaller molecules can then be taken up by the cells and used for a number of functions.
Break down
- When an organism eats, it ingests large, biological molecules (e.g. carbohydrates).
- These biological molecules are important to allow the organism to survive.
- The molecules could be used in the cells for important reactions (e.g respiration) but they are too large to be transported into the cells.
- The large molecules must first be broken down.
Hydrolysis
- Hydrolysis is the reaction that breaks down large, biological molecules.
- The reaction requires water and splits larger molecules into their smaller components.
- These smaller molecules (e.g. glucose) can easily diffuse into cells or be transported using protein channels.
Products of hydrolysis
- Hydrolysis of protein produces amino acids.
- Hydrolysis of carbohydrate produces disaccharides and monosaccharides.
- Disaccharides are two monosaccharides joined together.
- Hydrolysation of lipids produces fatty acids and monoglycerides.
Test yourself on Monomers & Polymers
What are the smaller units from which larger molecules are made?
Which of the following is an example of a polymer?
Which of the following statements about monomers and polymers are true?
What is the product of the condensation of two monosaccharides?
Which of the following statements about condensation reactions are true?