Medical Bacteriology and Archaebacteria

Archaebacteria are known to be the oldest living organisms on earth. They are classified as bacteria because they resemble bacteria when observed under a microscope. But they are completely distinct from prokaryotes. However, they share slightly.common characteristics with the eukaryotes These can easily survive under very harsh conditions such as the bottom of the sea and the volcanic vents.and are thus known as extremophiles Morphology Bacteria display a wide diversity of shapes and sizes. Bacterial cells are about one-tenth the size of eukaryotic cells and are typically 0.5–5.0 micrometers(µm) in length. However, a few species are visible to the naked eye , for example,.Thiomargarita is up to half a millimeter long Among the smallest bacteria are members of the genus Mycoplasma, which measure only 0.3 micrometers, as small as the largest viruses. Some.bacteria may be even smaller Morphology :Bacterial Classification according to Morphology Most bacterial species are spherical, called cocci -1 (sing. coccus).Others are rod-shaped, called bacilli (sing. bacillus) -2 Some bacteria, called ______, are shaped like slightly -3.

Curved rods or comma-shaped others can be spiral-shaped, called spirilla, or tightly -4.coiled, called spirochaetes A small number of species even have tetrahedral or ______ shapes This wide variety of shapes is determined by the bacterial cell wall

A cell wall, cell membrane, cytoplasm, ribosomes, plasmids, flagella, and a.nucleoid region Cell Wall - Outer covering of the cell that protects the bacterial cell.and gives it shape Cytoplasm - A gel-like substance composed mainly of water that also contains enzymes, salts, cell components, and various organic.molecules Cell Membrane or Plasma Membrane - Surrounds the cell's.cytoplasm and regulates the flow of substances in and out of the cell Nucleoid Region - Area of the cytoplasm that contains the single.bacterial DNA molecule Plasmid -most bacteria also contain small independent pieces of DNA called plasmid that often encode for traits that are advantageous but not essential to their bacterial host. Plasmids can be easily gained or lost by a bacterium and can be transferred between bacteria. So plasmids can be described as an.extra chromosomal DNA in a bacterial cell Flagella - Long, whip-like protrusion that aids in.cellular locomotion Endospores- Fimbriae - are protein tubes that extend out from the outer membrane. They are generally short in length and present in high numbers about the entire bacterial cell surface. Fimbriae usually.function to facilitate the attachment of a bacterium to a surface Pili-.Ribosomes - Cell ______ responsible for protein production are bacterial survival ______ that are highly resistant to many different types of chemical and environmental stresses and therefore enable the survival of bacteria in environments that would be lethal for these cells are similar in structure to fimbriae but are much longer and present on the bacterial cell in low numbers. Pili are involved in the process of bacterial conjugation where they are called conjugation pili or sex pili. Pili are absent in gram-positive bacteria and present in gram.negative bacteria The bacterial cell wall differs from that of all other organisms by the presence of peptidoglycan which is located immediately outside of the cytoplasmic membrane. Peptidoglycan is made up of a pol.

Bacterial cells typically contain the following ______

Plasmid -most bacteria also contain small independent pieces of DNA called ______

Plasmids can be easily gained or lost by a bacterium and can be transferred between bacteria. So ______s can be described as an.extra chromosomal DNA in a bacterial cell Flagella - Long, whip-like protrusion that aids in.cellular locomotion Endospores- Fimbriae - are protein tubes that extend out from the outer membrane. They are generally short in length and present in high numbers about the entire bacterial cell surface. Fimbriae usually.function to facilitate the attachment of a bacterium to a surface Pili-.Ribosomes - Cell structures responsible for protein production are bacterial survival structures that are highly resistant to many different types of chemical and environmental stresses and therefore enable the survival of bacteria in environments that would be lethal for these cells are similar in structure to fimbriae but are much longer and present on the bacterial cell in low numbers. Pili are involved in the process of bacterial conjugation where they are called conjugation pili or sex pili. Pili are absent in gram-positive bacteria and present in gram.negative bacteria The bacterial cell wall differs from that of all other organisms by the presence of peptidoglycan which is located immediately outside of the cytoplasmic membrane. Peptidoglycan is made up of a pol.

Cell Wall - Outer covering of the ______ that protects the bacterial ______.and gives it shape Cytoplasm - A gel-like substance composed mainly of water that also contains enzymes, salts, ______ components, and various organic.molecules Cell Membrane or Plasma Membrane - Surrounds the ______'s.cytoplasm and regulates the flow of substances in and out of the ______ Nucleoid Region - Area of the cytoplasm that contains the single.bacterial DNA molecule

Bacterial structure Bacteria, despite their simplicity, contain a well-developed cell structure which is responsible for many of their unique biological.

Nucleoid Region - Area of the cytoplasm that contains the single.bacterial DNA molecule Plasmid -most bacteria also contain small independent pieces of DNA called ______ that often encode for traits that are advantageous but not essential to their bacterial host.

Flagella - Long, whip-like protrusion that aids in.cellular locomotion Endospores- Fimbriae - are protein tubes that extend out from the outer membrane. They are generally short in length and present in high numbers about the entire bacterial cell surface. Fimbriae usually.function to facilitate the attachment of a bacterium to a surface Pili-.Ribosomes - Cell structures responsible for protein production are bacterial survival structures that are highly resistant to many different types of chemical and environmental stresses and therefore enable the survival of bacteria in environments that would be lethal for these cells are similar in structure to fimbriae but are much longer and present on the bacterial cell in low numbers. Pili are involved in the process of bacterial conjugation where they are called conjugation pili or sex pili. Pili are absent in gram-positive bacteria and present in gram.negative bacteria The bacterial cell wall differs from that of all other organisms by the presence of peptidoglycan which is located immediately outside of the cytoplasmic membrane. Peptidoglycan is made up of a pol.

Cell Membrane or Plasma Membrane - Surrounds the cell's.cytoplasm and regulates the flow of substances in and out of the cell Nucleoid Region - Area of the cytoplasm that contains the single.bacterial DNA molecule Plasmid -most bacteria also contain small independent pieces of DNA called plasmid that often encode for traits that are advantageous but not essential to their bacterial host. Plasmids can be easily gained or lost by a bacterium and can be transferred between bacteria. So plasmids can be described as an.extra chromosomal DNA in a bacterial cell Flagella - Long, whip-like protrusion that aids in.cellular locomotion Endospores- Fimbriae - are protein tubes that extend out from the outer membrane. They are generally short in length and present in high numbers about the entire bacterial cell surface. Fimbriae usually.function to facilitate the attachment of a bacterium to a surface Pili-.Ribosomes - Cell structures responsible for protein production are bacterial survival structures that are highly resistant to many different types of chemical and environmental stresses and therefore enable the survival of bacteria in environments that would be lethal for these cells are similar in structure to fimbriae but are much longer and present on the bacterial cell in low numbers. Pili are involved in the process of bacterial conjugation where they are called conjugation pili or sex pili. Pili are absent in gram-positive bacteria and present in gram.negative bacteria The bacterial cell wall differs from that of all other organisms by the presence of peptidoglycan which is located immediately outside of the cytoplasmic membrane. Peptidoglycan is made up of a pol.