Microbiology Chapter 3.3 Flashcards
15 Questions
100 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What are the shapes of prokaryotic cells?

  • Cylindrical (rod) (correct)
  • Hexagonal
  • Spherical (coccus) (correct)
  • Spiraled
  • What is a rod shape bacterium sometimes called?

    bacillus

    What is a coccobacillus?

    It's a rod shaped bacterium so short that it can easily be mistaken for a coccus.

    What is a Vibrio?

    <p>A short curved rod.</p> Signup and view all the answers

    What is a Spirillum?

    <p>A curved rod long enough to form spirals.</p> Signup and view all the answers

    What is Spirochete?

    <p>A long, helical cell with a flexible cell wall and a unique mechanism of motility.</p> Signup and view all the answers

    What does Pleomorphic mean?

    <p>Bacteria that characteristically vary in their shape.</p> Signup and view all the answers

    Cocci that occur in pairs are called?

    <p>Diplococci</p> Signup and view all the answers

    What is the structure surrounding a prokaryotic cell?

    <p>Cytoplasmic membrane, cell wall.</p> Signup and view all the answers

    What is the nucleoid of the prokaryotic cell?

    <p>It is the gel-like area where the chromosomes are located.</p> Signup and view all the answers

    What contents make up the cell envelope?

    <p>Capsule</p> Signup and view all the answers

    When water and nutrients are depleted, what structure do cells form?

    <p>A fruiting body.</p> Signup and view all the answers

    What is the natural habitat of bacteria called?

    <p>Biofilms.</p> Signup and view all the answers

    Which of the following is NOT a filamentous appendage of prokaryotic cells?

    <p>Capsule</p> Signup and view all the answers

    What structure provides buoyancy to a cell?

    <p>Gas vesicles.</p> Signup and view all the answers

    Study Notes

    Prokaryotic Cell Shapes

    • Common bacterial shapes include spherical (coccus) and cylindrical (rod or bacillus).
    • Coccobacillus refers to a very short rod-shaped bacterium resembling a coccus.
    • Vibrio are short, curved rods while spirilla are curved rods capable of forming spirals.
    • Spirochetes are long, helical cells with flexible cell walls and unique movement mechanisms.
    • Pleomorphic bacteria exhibit variability in their shapes.

    Prokaryotic Cell Groupings

    • Prokaryotes primarily reproduce by binary fission, leading to characteristic arrangements based on division planes.
    • Diplococci are cocci occurring in pairs, often indicative of specific bacterial identification like Neisseria gonorrhoeae.
    • Cocci dividing in multiple planes can form cubical packets (ex. Genus Sarcina) or clusters (ex. Staphylococcus).

    Multicellular Associations and Biofilms

    • Some bacteria form multicellular associations, like myxobacteria that glide together and form aggregates to degrade organic material.
    • In nutrient-depleted environments, cells may aggregate to form visible structures called fruiting bodies.
    • Bacteria typically inhabit surfaces in assemblages known as biofilms.

    Structure of Prokaryotic Cells

    • The cytoplasmic membrane acts as a selective barrier, controlling the passage of molecules.
    • The cell wall provides structural integrity, preventing cell content from escaping and aiding in motility and adhesion.
    • The cell envelope consists of the capsule (if present), cell wall, and cytoplasmic membrane.

    Cell Envelope Components

    • Capsule: Distinct, gelatinous, helps bacteria adhere to surfaces and evade immune responses.
    • Slime Layer: Irregular and diffuse, also aids in adhesion.
    • Cell wall composed of peptidoglycan differs between Gram-positive (thick layer) and Gram-negative (thin layer surrounded by outer membrane with lipopolysaccharides).

    Cytoplasmic Contents

    • Plasma consists of water, enzymes, proteins, carbohydrates, lipids, and inorganic molecules; ribosomes and storage granules are present.
    • Nucleoid is the gel-like region containing chromosomes, not membrane-bound.

    Key Prokaryotic Cell Structures

    • Filamentous Appendages: Proteins that form helical chains for motility.
    • Flagella: Provide motion.
    • Pili serve various functions; types include fimbriae (adhesion) and sex pili (DNA transfer).
    • Ribosomes are critical for protein synthesis, forming 70s ribosomes from 30s and 50s subunits.
    • Gas vesicles help with buoyancy.

    Genetic Material

    • DNA contains genetic information, typically as a single circular strand.
    • Plasmids are extra-chromosomal DNA contributing to genetic variation.
    • Endospores are dormant cells resistant to unfavorable conditions.

    Studying That Suits You

    Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

    Quiz Team

    Description

    This quiz consists of flashcards covering the key concepts of prokaryotic cell shapes in Microbiology Chapter 3.3. Learn about the different forms of bacteria, such as cocci and bacilli, and their characteristics. These flashcards will enhance your understanding of bacterial morphology.

    More Like This

    Bacterial Morphology Flashcards
    9 questions
    BIOL212 W2-1
    80 questions

    BIOL212 W2-1

    SteadfastEcoArt4504 avatar
    SteadfastEcoArt4504
    Use Quizgecko on...
    Browser
    Browser