A chromosome is an 'X' shaped gene which contains DNA, found inside living cells. Chromosomes are easily seen using a microscope and are normally invisible most of the time (tâ¦his period of time called 'interphase') but become visible when the cell starts to multiply.
Bacterial DNA â a circular chromosome plus plasmids. The DNA of most bacteria is contained in a single circular molecule, called the bacterial chromosome. The chromosome, along with several proteins and RNA molecules, forms an irregularly shaped structure called the nucleoid.This sits in the cytoplasm of the bacterial cell.In addition to the chromosome, bacteria often contain plasmids â small circular DNA molecules. Bacteria can pick up new plasmids from other bacterial cells (during conjugation) or from the environment.his sits in the cytoplasm of the bacterial cell. In addition to the chromosome, bacteria often contain plasmids â small circular DNA molecules. Bacteria can pick up new plasmids from other bacterial cells (during conjugation) or from the environment.
DNA gyrase, often referred to simply as gyrase, is an enzyme that relieves strain while double-strand DNA is being unwound by helicase. It is also known as DNA topoisomerase II.This causes negative supercoiling of the DNA.Bacterial DNA gyrase is the target of many antibiotics, including nalidixic acid, novobiocin, and ciprofloxacin.t is also known as DNA topoisomerase II. This causes negative supercoiling of the DNA. Bacterial DNA gyrase is the target of many antibiotics, including nalidixic acid, novobiocin, and ciprofloxacin.