Question

Describe how catalysts work and give an example of one. What is the Kd for a catalyst and how would you interpret a low Kd. How do non-specific DNA binding proteins work? How do specific DNA binding proteins work?

Answer 1

Catalyst:

A catalyst is a substance upon addition to a particular reaction it speeds up the reaction.It generally speeds up the reaction by reducing the activation energy.There are different types of catalyst available which includes Acid base catalyst,electro catalyst,organism catalyst,Photo catalyst and enzyme catalyst.Mostly enzymes are proteins which are widely used catalysts in many biochemical reactions.In many reactions or mechanisms, a temporary intermediate is formed by the catalyst after that it is regenerated to form the original catalyst in a cyclic process.

Example:

Decomposition of Hydrogen peroxide:

Hydrogen peroxide will decompose into water and oxygen gas.In this process two molecules of hydrogen peroxide will release two molecules of water and one molecule of oxygen.
So inorder to speed up the process potassium permanganate can be used as a catalyst.So it produces large amount of heat and vapours.

Kd:

Kd for a catalyst is a dissociation constant at equilibrium in which the large object is to dissociate in to smaller one relating with activation energy.Generally lowering of activation energy resulting increase in dissociation constant value which means port activity of the catalyst.

Non specific and specific DNA binding proteins:

Generally Different DNA-binding proteins have been found with different interaction modes with DNA.
Non specific DNA protein binding:

Non specific DNA binding proteins involved in various process which is not directly attaches with DNA but involved in process to which is a part of DNA development.Examples like histone proteins bind to the nuclosome region and helps in chromosome packaging.Another example is HMG protein ( High mobility group) in chromatin packaging.It generally binds to the distorted regions of DNA and make the nucleosome to bend and arrange chromosomes compactly.

DNA-Specific binding proteins:

DNA specific binding proteins are the proteins or enzyme bio molecules which are specifically bind to the target region of the DNA molecule (in promoter regions,operators) and does the process.Some of them are transcription factors which are involved in carrying out the process of transcription, And many polymerases (DNA polymerase which involved in initiating Replication process ,and also does proof reading) ,others like nucleases involved in cleaving the DNA molecules by attaching with the bases.

Hope this helps you :)