- 1 How do antibiotics interfere with cellular processes?
- 2 What effect does inhibiting gyrase have on the DNA replication process?
- 3 How would inhibiting the action of DNA gyrase stop the growth of bacterial cells?
- 4 Which of the following antibiotics inhibit DNA gyrase?
- 5 What are 4 possible side effects of using antibiotics?
- 6 What are the 5 mechanisms of action of antibiotics?
- 7 What is the function of gyrase?
- 8 What is the difference between DNA gyrase and topoisomerase?
- 9 Why is Primase important?
- 10 What causes supercoiling of DNA?
- 11 Is DNA gyrase found in prokaryotes?
- 12 What is negative supercoiling of DNA?
- 13 Is DNA a polymerase?
- 14 What antibiotics inhibit DNA synthesis?
- 15 What is the role of DNA gyrase in transcription?
How do antibiotics interfere with cellular processes?
Antibiotics disrupt essential processes or structures in the bacterial cell. This either kills the bacterium or slows down bacterial growth. Depending on these effects an antibiotic is said to be bactericidal or bacteriostatic.
What effect does inhibiting gyrase have on the DNA replication process?
The inhibition of the supercoiling activity causes the chromosome to reach a superhelical state that blocks replication forks, induces the SOS response, and eventually interrupts chromosome segregation.
How would inhibiting the action of DNA gyrase stop the growth of bacterial cells?
Inhibiting the ATPase activity of gyrase blocks the introduction of negative supercoils in DNA and traps the chromosome in a positively supercoiled state that may have a downstream impact on cell physiology and division.
Which of the following antibiotics inhibit DNA gyrase?
Currently, the 6-ﬂuoroquinolones class of compounds are the only DNA gyrase inhibitors used in clinical practice. The quinolones create restriction in the process of rejoining double-strand breaks in DNA while aminocoumarins and cyclothialidines (cyclic peptides) block the ATPase activity of DNA gyrase [11,12].
What are 4 possible side effects of using antibiotics?
Common side effects of antibiotics
- feeling of fullness.
- loss of appetite.
- stomach cramping or pain.
What are the 5 mechanisms of action of antibiotics?
- Five Basic Mechanisms of Antibiotic Action against Bacterial Cells:
- Inhibition of Cell Wall Synthesis.
- Inhibition of Protein Synthesis (Translation)
- Alteration of Cell Membranes.
- Inhibition of Nucleic Acid Synthesis.
- Antimetabolite Activity.
What is the function of gyrase?
DNA gyrase is an essential bacterial enzyme that catalyzes the ATP-dependent negative super-coiling of double-stranded closed-circular DNA. Gyrase belongs to a class of enzymes known as topoisomerases that are involved in the control of topological transitions of DNA.
What is the difference between DNA gyrase and topoisomerase?
DNA gyrase and topoisomerase IV are the two type II topoisomerases present in bacteria. Gyrase is involved primarily in supporting nascent chain elongation during replication of the chromosome, whereas topoisomerase IV separates the topologically linked daughter chromosomes during the terminal stage of DNA replication.
Why is Primase important?
Primase is the enzyme that synthesizes RNA primers, oligonucleotides that are complementarily bound to a nucleic acid polymer. Primase is required because DNA polymerases cannot initiate polymer synthesis on single-stranded DNA templates; they can only elongate from the 3′-hydroxyl of a primer.
What causes supercoiling of DNA?
Supercoiling occurs when the molecule relieves the helical stress by twisting around itself. The hydrogen bonds (holding together complementary bases) break and part of the double helix separates. Strand separation is required for transcription (copying DNA to RNA) and replication (copying DNA to DNA ).
Is DNA gyrase found in prokaryotes?
Gyrase is present in prokaryotes and some eukaryotes, but the enzymes are not entirely similar in structure or sequence, and have different affinities for different molecules.
What is negative supercoiling of DNA?
Positive supercoiling of DNA occurs when the right-handed, double-helical conformation of DNA is twisted even tighter (twisted in a right-handed fashion) until the helix begins to distort and “knot.” Negative supercoiling, on the other hand, involves twisting against the helical conformation (twisting in a left-handed
Is DNA a polymerase?
DNA polymerase is responsible for the process of DNA replication, during which a double-stranded DNA molecule is copied into two identical DNA molecules. Scientists have taken advantage of the power of DNA polymerase molecules to copy DNA molecules in test tubes via polymerase chain reaction, also known as PCR.
What antibiotics inhibit DNA synthesis?
Quinolones are a key group of antibiotics that interfere with DNA synthesis by inhibiting topoisomerase, most frequently topoisomerase II ( DNA gyrase), an enzyme involved in DNA replication.
What is the role of DNA gyrase in transcription?
DNA gyrase catalyzes the con- version of relaxed closed circular DNA into negatively supertwisted form, thereby promoting replication and transcription [2-S]. The apparent inhibition of repli- cation by novobiocin and coumermycin A, is by inter- action with one of the subunits of DNA gyrase [3,4,6].