The cell membrane fluid mosaic similar to eukaryotic

Info icon This preview shows pages 5–8. Sign up to view the full content.

View Full Document Right Arrow Icon
The Cell Membrane • Fluid Mosaic similar to Eukaryotic (“Standard”) Cell Membrane - Usually lacks Sterols But many Bacteria have Sterol-like Hopanoids that stabilize the Cell Membrane. And Mycoplasmas and some Methanotropic Bacteria have Sterols in their Cell Membranes. • All-Singing, All-Dancing Structure in Bacteria - Site of Respiration, Photosynthesis, and Biosyntheses - Important during Cell Division • New Cell Membrane Synthesis substitutes for the Spindle Apparatus to separate Bacterial Chromosomes
Image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Structure of Bacteria Page 6 Internal Structures Cytoplasm (G = cell form) • 4/5th Water; 1/5th Stuff (Enzymes, Proteins, Lipids, Carbohydrates) Ribosomes (G = ribo nucleic acid + body) • Bacteria have 70S Ribosomes - 30S Small Subunit (S= Svedberg, a Sedimentation Coefficient) • 21 Proteins + 16S rRNA - 50S Large Subunit • 34 Proteins + 23S rRNA and 5S rRNA Nucleoid (Nuclear Region) • Chromosome (G = colored [“stained”] body) - Most Bacteria have a single circular, supercoiled, double-stranded DNA Chromosome in an irregularly shaped Area There are always Exceptions in Biology and in Cell Phone Contracts. Rhodobacter sp. (a Purple Bacterium) has two circular Chromosomes. Streptomyces sp. (an Actinomycete) has a Linear Chromosome. Rapidly growing Bacteria frequently contain more than one Copy of their Chromosome. The Chromosome in E. coli is a Circle measuring 1.58 mm. Think about the difficulty of putting a 1580 μ m Circle of DNA into a 1 x 2 μ m Cell. • Plasmids (L = small [feminine entity] in the cytoplasm) - Circular, double-stranded DNA Molecules in the Cytoplasm • Can exist and replicate Autonomously • Can integrate with the Bacterial Chromosome - Confer intriguing Advantages • F Factors encode for Conjugation, a Sexual Process • R Factors encode for Drug Resistance Bacterial Chromosomes are like Computer Hard-Drives. Plasmids are like USB Flash Drives. Gas Vesicles (L= little bladder) • Provide Buoyancy for (usually) Photosynthetic Bacteria Gas Vesicles are usually arranged in Bundles termed Gas Vacuoles (L= space). Gas Va cuoles can be seen with Pha se Contrast Microscopy. Gas Ve sicles can only be seen with E lectron Microscopy.
Image of page 6
Structure of Bacteria Page 7 Flagella (L = little whip) Thread-like Locomotion Appendage • Positioning is frequently Species-specific - Monotrichous Bacteria (G= one hair) have a Flagellum at one End of the Cell - Amphitrichous Bacteria (G= both hairs) have a Flagellum at both Ends of the Cell - Lophotrichous Bacteria (G= tufted hairs) have Clustered Flagella (usually clustered at one End, like Bunsen and Beaker) - Peritrichous Bacteria (G= surrounding hairs) have numerous Flagella covering the Cell Three Components • Filament • Hook • Basal Structure (Gram Positive Bacteria lack L and P Rings) - L Ring (Lipopolysaccharide) - P Ring (Peptidoglycan) - MS Ring (Membrane & Supramembrane [L = on top] ) - C Ring (Cytoplasm) - The MS and C Rings function together as a Reversible Turbine Rotor • Motor Proteins (Mot A and Mot B) form the Stator
Image of page 7

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Image of page 8
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern