Quick question about microbiology

[thechairman]

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What is the functional difference between plasmids and chromosomes in bacteria? i know plasmids are used in protein synthesis and are the DNA of choice in bacterial transformations, but is the purpose of the chromosomes?

will the MCAT make the distinction between bacterial nucleoid (the chromsome region) and plasmids?

 

[axp107]

Yeah you definitely have to know that they're different. And yes, if necessary, they will make that distinction...

Because they test 1 concept at a time. So if they were asking about plasmids, they would have a passage about it.. or would ask simple questions about conjugation. But that's about it really..

 

[DrShoshana]

Plasmids are basically the same as chromosomes, and they are defined as an extra chromosomal ring. They are self-replicating which is a very important trait, and usually they carry things such as antibiotic resistance. They do not hold all the DNA of the cell, all of the DNA of the cell is found in the nucleoid. They only hold a small amount of DNA, and they are useful for transferring desirable triats (such as antibiotic resistance) between bacteria in the lab or in nature (meaning naturally or manually). At least that is how I understand it! Hope this helps!

 

[sushichopstickz]

From what I remember,

Plasmids: extrachromosomal DNA (double stranded) that are circular in shape; plasmids often carry genes that confers bacterial resistance to certain antibiotics--so when you hear about bacterial resistance to antibiotics, it's because the plasmids with resistivity genes were conjugated via pilus to a F- bacteria. Plasmids can sometime integrate itself into the chromosome, becoming a Hfr bacterial.

Chromosome: bacterial chromosome is circular in shape and is also double stranded, the chromosome houses most of the bacterial genes, including those that codes for bacterial ribosomes and structural/functional proteins

Nucleoid: is the region where you would find the chromosomes '

The way I think of it is that plasmids are in auxlliary to the chromosome, in that, it's existence is to help the bacterial survive in certain environments. Bacteria don't necessary need plasmids, but with it bacteria can exchange information more easily among its colony members and enable it to adapt more readily to changing environments.


I hope this helps 🙂