BIO 320 (1).docx - BIO 320 INTRODUCTION TO BIOLOGICAL...

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BIO 320INTRODUCTION TO BIOLOGICALDIVERSITYTitle of Practical: EubacteriaGroup: A4AS1204_03Group Members:NameMatric NoResult ScoreJudith Somiyar Raymond2017641874Muhammad Hazwan Hamim bin Shahfar Amil2017681342Muhammad Danial bin Zulkepli2017854412Date of experiment: 18thMarch 2019Lecturer’s Name: Dr. Hasnun Nita Ismail
1.0 Title of Experiment: Eubacteria2.0 Objectives1.To define coccus, bacillus, spirillum, Gram stain.2.To describe and explain characteristics of eubacteria.3.To identify and classify the organisms studied in this exercise.4.To distinguish Gram-positive and Gram-negative bacteria, indicating their susceptibility to certain antibiotics. 3.0 IntroductionEubacteria, or “true” bacteria, are single-celled prokaryotic microorganisms thathave a range of characteristics and are found in various conditions throughout all parts ofthe world. Since eubacteria is so common, it comprises one of the three main domains oflife, along with the Archaea and the Eukarya.Eubacteria are prokaryotes, meaning their cells do not have nuclei in whichtheir DNA is stored. Eubacteria are enclosed by a cell wall. The wall is made of cross-linked chains of peptidoglycan which is a polymer that combines both amino acid andsugar chains. This gives the wall of the bacteria the strength needed to maintain its shapeand size during changing environments. Unlike the eukaryotes, bacteria have cholesterolpresent in the membrane to enhance permeability of the membrane and increase stiffness.Eubacteria are typically classified into five different phyla: Chlamydia,Cyanobacteria (Blue-green algae), Gram-positive bacteria, Proteobacteria, andSpirochetes. Other than that, bacteria commonly take on one of three shapes: bacillus,
coccusand spirillum. Bacillushave a rod shape, coccus have a spherical shape, andspirillum have a spiral or wave shape. Their shape was often taken or used as aclassification system until recently.
4.0 Methodology4.1 Experiment 1: Bacteria (Heterotrophic Eubacteria): Are bacteria Present in the Lab?1. Four petri dishes containing sterile nutrient agar has been labelled as “Dish 1: Control”, “Dish 2: Dry Swab”, “Dish 3: Treatment A,” and “Dish 4: TreatmentB”. 2. The surface of the dish can in the lab was swabbed using a sterile cotton swab.3. The lid of Dish 2 were lifted slowly as little as possible to run the swab over the surface of the agar without ruining it.4. The lid was securely taped to half of bottom of the dish.5. Two different tissue paper were soaked with Liquid A (tap water) and Liquid B (70% ethyl alcohol) respectively.6. Tissue paper soaked with liquid A was used to wipe the surface of the sterile nutrient agar in Dish 3 while the other tissue paper soaked with Liquid B was used to wipe the agar surface of Dish 4.7. Step 2 until step 4 was repeated with different surface areas such as the surface under table for Dish 3 and the surface of the sink in the lab for Dish 4. 8. The cultures were placed in an incubator oven for 2 days. 9. After 2 days, the culture was scraped by using needle in preparing a wet mount

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