Question

• Define polymer, monomer, dehydration, hydrolysis, peptide bonds, and phosphodiester bonds
• Know the basic structure of an amino acid, and how the variable R groups determine the properties of the amino acid.

Google is not really helpful when it comes to questions like this.

Can someone please explain for me?

Thank you !

Answer 1

A polymer is a very large molecule made of repeating units. Eg proteins are polymers made of repeating units called aminacids, nucleic acids are polymers of nucleotides etc

A monomer is the repeating units in a polymer: eg amino acid is the monomer of protein, nucleotide is the monomer of nucleic acids.

Dehydration : Dehydration is a reaction which involves removal of a water molecule from the reactants : for example peptide bond formation is a dehydration reaction. When carboxyl group of one aminoacid reacts with amino group of another amino acid to form peptide bond, a molecule of water is released.

Hydrolysis: literally means water - splitting , It is a reaction in which the reactants ( and sometimes water molecule itself ) split to in the presence of water, for eg: the splitting of water molecule to form hydrogen and oxygen, the splitting of ester molecule in the presence of H2O to form alcohol and acid

Peptide bond, It is the bond between carboxyl group of one amino acid and amino group of the other with the release of a molecule of water.

Phosphodiester bond: It is the bond that holds the nucleotides in an nucleic acid chain. It is the bond between OH group of sugar molecule of one nucleotide with phosphate group of another nucleotide.

Aminoacids are molecules with amino group and carboxyl group attached to the same carbon atom. The other two valencies of the carbon atom are fulfilled by a Hydrogen atom and an R group which is specific to the aminoacid.The charge and all the other properties of the aminoacids , thus are determined by the R group since every aminoacid differs from each other in their R group only.