Tag: biology

Penicillin targets the synthesis of peptidoglycan in bacterial cell walls. Mycoplasma lacks a cell wall, slime molds are eukaryotes, and Pseudomonas has a different cell wall structure/permeability, making them resistant to penicillin.

• Discovery of penicillin antibiotic by Fleming was an accidental discovery.
• Fleming was working with different bacterial strains to study the effect of lysozyme in fighting of bacterial infection in human body.
• In his lab there were many petri dish containing different strains of bacteria, he observed that one of the petridishes containing the strain for bacteria  Staphylococcus was infected by the growth of a fungus
• This fungus growing along with the bacterial colony inhibited the growth of the bacterial colony
• On further observation Fleming saw that the chemical substances secreted by the mold inhibited the bacterial growth. He named it Penicillin after the name of the organism ie Penicillium notatum
• So, the correct answer is Penicillium notatum 
  

• In September 1928 when Alexander Fleming observed his Petri dishes of the bacterial culture he notice that the culture of bacteria Staphylococcus has a mold growing over it which has inhabited its growth in that area.
• Upon observing he found that the mold was a strain of fungus Penicillium notaum and its was secreting some substance which inhibited the growth of the bacteria.
• He named it penicillin after the organism from which it is secreted.
• So the answer Alexander Fleming who discovered the first antibiotic penicillin is correct.
  

While Alexander Fleming discovered penicillin, Howard Florey and Ernest Chain were responsible for isolating and purifying it, and demonstrating its clinical potential as an effective drug.

The discovery of Penicillin was a case of serendipity and it was observed on a culture plate of Staphylococcus aureus that was contaminated by a fungus species. 

• Sutton deduced that chromosomes are the basis of heredity and that the reduction of chromosomes in meiosis is directly related to Mendel's laws of inheritance.
• Thomas Hunt Morgan described the phenomenon of linkage and crossing over. Morgan imagined that genes on chromosomes were similar to pearls on a string, in other words, they were physical objects. The closer two genes were to one another on a chromosome, the greater their chance of being inherited together. In contrast, genes located farther away from one another on the same chromosome were more likely to be separated during recombination. Therefore, Morgan correctly proposed that the strength of linkage between two genes depends upon the distance between the genes on the chromosome. This proposition became the basis for construction of the earliest maps of the human genome.
• James Dewey Watson discovered the structure of DNA in 1953 with Francis Crick.
• Scottish bacteriologist Alexander Fleming accidentally discovered the antibiotic in 1928, when he came back from a vacation and found that a green mold called Penicillium notatum had contaminated Petri dishes in his lab and were killing some of the bacteria he’d been growing.

Antibiotic is a medicine which inhibits the growth of microbes. This term was coined by Selman Waksman. They are produced by many bacteria, fungi, and other microorganisms. Some of them increase the activity of mast cell resulting into allergy. They are specific for the disease.

(A)Cristian Haneen verified the Purification of enzyme zennet.

Selman Waksman, the microbiologist who discovered streptomycin, first used the word "antibiotic" in the medical sense in 1943. 

Alexander Fleming, Howard Florey, and Ernst Chain were jointly awarded the 1945 Nobel Prize in Physiology or Medicine for the discovery of penicillin and its curative effect in various infectious diseases.