Please answer below Molecular biology question from 227 to 236. Do not plgirized
ID: 322575 • Letter: P
Question
Please answer below Molecular biology question from 227 to 236. Do not plgirized answer from any web-sources, otherwise reported as a spam.
227. Explain why fatty acid synthase has multiple domains. What is the function of the acyl carrier protein in this complex? How is it attached to CoA? 228. Explain the difference between gene duplication and divergence, and the role of each. Give one example of a protein that demonstrates this process. 230. What are the advantages to quaternary structure over having a single long polypeptide chain? 232. Describe a typical protein-protein interface, and what is required to allow for protein interactions. 233. Are NAD- and ATP-binding domains generally conserved or unique? Why? 234. Why do proteins have cofactors (what role do they serv 235. Describe the two ways proteins can interact with DNA, and the differences between both. Which is similar to the RNA recognition motif? 236. How do proteins differentiate between ssRNA, dsRNA, DNA-RNA hybrids, and dsDNA?Explanation / Answer
The answers are following :-
227 - The enzymes of fatty acid synthesis are packaged together in a complex called as fatty acid synthase (FAS). FAS is a polypeptide chain with multiple domains, each with distinct enzyme activities required for fatty acid biosynthesis. :-
• ACP:CoA is used as an activator for - oxidation. For fatty acid biosynthesis, the activator is a protein called the acyl carrier protein (ACP). It is part of the FAS complex. The acyl groups get anchored to the CoA group of ACP by a thioester linkage
• Condensing enzyme/-ketoacyl synthase (K-SH). Also part of FAS, CE has a cysteine SH that participates in thioester linkage with the carboxylate group of the fatty acid.
• During FA biosynthesis, the growing FA chain alternates between K-SH and ACP-SH
228 - general intro - Gene duplication, followed by divergence is a source of new genes in genomes. Divergence literally means to go in different directions. we mean that the sequences of the gene copies are becoming different from each other because of the accumulation of mutations.
~ gene duplication is where, for some reason, the gene in question has been copied and inserted somewhere in the genome. it could be right next to it, or even on another chromosome, but there is more than one copy of that particular gene now in existance in that genome. this can act as a redundancy in the cell (as in, if one copy of the gene gets mutated and is no longer functional the other gene can compensate), or double the amount of that gene will be expressed and so you may have larger quantities of that protein in the cell. it can be beneficial or deleterious depending on what the gene codes for and where it is inserted.
~ gene divergence is when two copies of the same gene become mutated to the point that they now have different functions. their functions have diverged. if you are meaning divergence (not gene divergence), this is the point where two groups of one species have changed so much they can no longer interbreed to produce fertile offspring, and are considered different species.
EXAMPLE OF A PROTEIN IS GLOBIN GENE AND acetylcholine esterase genes
230 -
233 - ATP-binding domains are conserved, as in their amino acid sequence and consequent folding of that domain are incredibly similar in most proteins. ATP is a particular shape, and that doesn't change. A binding site will always fit the shape and charge of the molecule it is going to bind, or it wouldn't work, therefore ATP-binding sites would always be the same, and the gene sequence, or at least the amino acid sequence would always be very similar in all organisms.
234 - A cofactor is a non-protein chemical compound that is bound to a protein and is required for the protein's biological activity.
they increase the rate of reaction or are required for enzyme function. Cofactors are not proteins but rather help proteins, such as enzymes, although they can also help non-enzyme proteins as well. Examples of cofactors include metal ions like iron and zinc.