_Lecture_1_Bacterial_Structure_,_Functions_&_Genetic_Dr_Nisreen.pdf

Lecture 1: Bacterial Structure , Functions & Genetic Dr: Nisreen jawad kadhim Objectives 1. Define the cellular organization of bacteria and know the differences between Eukaryotes and Prokaryotes. 2. Know major structures of bac...

Lecture 1: Bacterial Structure , Functions & Genetic Dr: Nisreen jawad kadhim Objectives 1. Define the cellular organization of bacteria and know the differences between Eukaryotes and Prokaryotes. 2. Know major structures of bacteria and its function. 3. Know the structure of cell wall of bacteria including the differences between Gram positive and Gram negative bacteria and main functions. 4. Know the external structures of bacteria with and functions. 5. Know the cytosol and internal structures of bacteria. 6. Describe bacterial spores and its application in the practice of medicine. 7. Know basic information about bacterial genetics The Difference Between Prokaryotes and Eukaryote Structure: Cell Wall Definition: It’s rigid, surrounds the cytoplasmic membrane and internal structures. Function : Rigidity Protection Shapes bacteria Cell division weight molecules Porous: permeable to low molecular Note from doctor: Mycoplasma naturally has no cell wall Two groups of bacteria depending on reaction to GRAM STAIN!  External Structures of Bacteria Flagella: Helical filaments Composed of protein FLAGELLIN. Found in Gram positive & Gram negative bacteria. Distribution: - Peritrichous - Monotrichous - Lophotrichous Function of Flagella: motility & chemotaxis  Spores of Bacteria Small, dense, metabolically inactive, non- reproductive structures produced by Bacillus & Clostridium. Enables the bacteria to survive adverse environmental conditions. Contain high concentration of Calcium dipicolonate. Resistant to heat, dissecation & disinfectants. Often remain associated with the cell wall. Spores are described as: Terminal spores Sub-terminal spores Central spores Spores germinate when growth conditions become favorable to produce vegetative cells. Application in medical practice :spore preparations used for checking the efficacy of Autoclaves, eg. Bacillus subtilis & Bacillus sterothermophilus  Bacterial Genetics: It is the study of inheritance and variation. And the genetic information is encoded in DNA. Function of genetic material: 1- Replication of the genome 2- Expression of DNA to mRNA then to protein. Genotype: the complete set of genetic determinants of an organism.