Question

Compare missense, nonsense, silent and insertion/ deletion mutations

8: Define oxidation and reduction

9: Compare and contrast endocrine, paracrine, or autocrine signals

10: Calculate the overall delta G of a series of reactions if given the delta G for each individual reaction

11: Describe the ribonucleotide reductase reaction and its regulation at both the allosteric and effector sites

12: Compare missense, nonsense, silent and insertion/ deletion mutations

Answer 1

Q8: Oxidation:This is defined as the loss of electrons and reduction is defined as the gain of electrons.This may be explained by the interconversion of ferrous ion (Fe²⁺) into Fe^3+.When Fe²⁺ loose an electron it will become Fe³⁺ and whenFe³⁺ gains an electron it will become Fe^2+.

^Q9

Autocrine signal	Paracrine signal	Endocrine signal
In this signalling, the signalling molecules produce an effect on same cell that generates it.	In this signalling. the signalling molecules released by a cell affect target cells which are in close proximity.	In this, the signalling molecules act on target cells which are distantly located from their site of synthesis.
Examples certain types of T lymphocytes.	Neurotransmitters	Hormones

Q10; Free energy is an additive property.To calculate the over all delta G, just sum up the Delta G of individual reactions.

Q11. This enzyme converts ribonucleotides into deoxyribonucleotides.Ribonucleotide reductase has two sub units RNR1 and RNR2 which form a heterodimeric tetramer The regulation of substrate specificity is mediated by RNR1 which contains both the allosteric sites. Effectors may lead to increase or decrease in its activity.

Missense Mutation	Non sense mutation	Silent Mutation	Insertion/ Deletion
In this case the changed base may code for a different amino acid. For example UCA codes for a serine. While ACA codes for threonine.For example sickle cell anemia is a classical example of mis sense mutation.	Sometimes, the codon with the altered base may become a termination or non-sense codon. For example change in the second base of serine codon (UCA) may result in UAA. The altered codon acts as a stop signal and causes termination of protein synthesis at that point.	The codon containing the changed base may code for the same amino acid. For example UCA codes for serine and change in the third base UCU still codes for serine. This is due to the degeneracy of the genetic code. Therefore there are no detectable effects in silent muatation.	Here in deletion mutation a single base is deleted from the frame while as in insertion mutation an addition of the base occurs. These types of mutations may change the reading frame of a polypeptide and can result in the formation of an incomplete polypeptide or its muated form.