Unit 6: Investigative Project
A: Undertake a literature research and review to produce an investigative project proposal
Assignment title: Project research
Introduction: The goal of this experiment, "Effect of Penicillin on Bacterial Growth," is to determine how
well penicillin kills bacteria or hinders their ability to grow and reproduce. The impact of various
penicillin concentrations on bacterial growth will also be examined in this experiment. This subject was
chosen because bacterial diseases including syphilis, meningitis, and throat infections are presently
treated with penicillin, which is heralded as the first miracle medication. It functions by activating other
enzymes that break down these defences while suppressing the enzymes that construct the bacterial cell
walls. A common antibiotic for treating staphylococcal and streptococcal bacterial infections is
penicillin. Penicillin, which belongs to the beta-lactam family of antibiotics, stops the growth of bacterial
cells, which ultimately results in the bacterium's death. Toxins, which are lethal compounds that cause
cell damage and illness in humans, are produced by certain bacteria. Certain bacteria really enter the
body and severely harm the tissue, causing illnesses like strep throat, urinary tract infections, and
numerous others. So, it's crucial to avoid bacterial growth. This is a laboratory-based work which
includes improving laboratory skills, including health and safety risks, planning a method and
hypothesis, collecting and analysing data.
Main body
Mainstream views on the topic: According to (Chow, Susan Penicillin mechanism. (Website) News
Medical Life Sciences. Available from: https://www.news-medical.net/health/Penicillin-Mechanism.aspx
(Accessed on: 23/03/2023). By attaching to DD-transpeptidase and preventing it from cross-linking and
producing new cell walls, penicillin prevents the growth of bacteria. Without a cell wall, a bacterial cell
is vulnerable to moisture and external molecular pressure, which swiftly destroys the organism. As
human cells lack a cell wall, therapy with penicillin kills bacteria without damaging them. Gram-
negative bacteria can be recognised from gram-positive bacteria by having thicker cell walls with less
peptidoglycan and thinner cell walls with more peptidoglycan. The lipopolysaccharide (LPS) coating on
the cell walls of gram-negative bacteria prevents antibiotics from penetrating them. Gram-positive
bacteria have the highest levels of DD-transpeptidase activity, hence they are the greatest targets for
penicillin. Another mainstream view on this topic which is from university of Hawaii (Weird Science:
Penicillin and the Cell Wall. (Website) University of Hawaii. Available from:
https://manoa.hawaii.edu/exploringourfluidearth/biological/aquatic-plants-and-algae/structure-and-
function/weird-science-penicillin-and-cell-wall. (Accessed on: 23/03/2023). Penicillin inhibits the
creation of the peptidoglycan molecule. The strength of the bacterial cell is derived from the firmly
interconnected peptidoglycan molecules, which also prevent cytoplasmic leakage. Almost all bacteria
have peptidoglycan as part of their cell walls. As the makeup of each organism's cell wall is unique,
penicillin has no effect on other species. For instance, cellulose is used by plants to build their cell walls.
The cell walls of algae can vary greatly. Algal cell walls contain cellulose, xylan, silica, carrageenan,
among a variety of other materials. Chitin makes up the majority of the cell walls in fungi. Although not
all of them, penicillin mostly kills bacterial cells. Despite the fact that some bacteria are still resilient to
the effects of antibiotics, the immune system is able to quickly eradicate them.
