Class notes
Lecture 3 Notes Microbiology 1 (MIB151S)
- Course
- Institution
Structures of Prokaryotic and Eukaryotic Lecture notes, Microbiology 1
[Show more]
Seller
Follow
Professor087
Content preview
MIB151S: Structures of Prokaryotic and Eukaryotic cell (Microbiology 1)Cape Peninsula University of Technology
Lecture 3 Notes
Microbiology 1
3.1 Overview of prokaryotic and eukaryotic cell structures
3.2 Size, shape and arrangement
3.3 Prokaryotic cell organisation
3.4 Prokaryotic cell membranes
3.5 Prokaryotic cell: the plasma membrane, internal membrane systems, cytoplasmic matrix, ribosomes and the
nucleoid
3.6 The prokaryotic cell wall
3.7 Peptidoglycan structure
3.8 Gram-positive cell walls
3.9 Gram-negative cell walls
3.10 The mechanism of Gram staining
3.11 The bacterial endospore
3.12 The eukaryotic cell: cytoplasmic matrix, microfilaments, intermediate filaments, and microtubules,
endoplasmic reticulum, Golgi apparatus, lysosomes and endocytosis, eukaryotic ribosomes, mitochondria,
chloroplasts and the nucleus
3.13 Cilia and flagella
3.14 Comparison of prokaryotic and eukaryotic cells
_______________________________________________________
Structures of Prokaryotic and Eukaryotic cells
3.1 Overview of prokaryotic and eukaryotic cell structure
Prokaryotes can be distinguished from eukaryotes in terms of their size, cell structure
and molecular make-up;
Prokaryotes can be divided into two major groups, i.e. Bacteria and Archaea;
Most bacteria can be divided into two groups based on their cell wall structure – either
Gram +ve or Gram –ve;
Some bacteria form resistant endospores in order to survive harsh environmental
conditions in a dormant state;
When eukaryotes reproduce, genetic material is distributed between cells by the highly
organised, complex processes of mitosis and meiosis;
Examples of eukaryotic organisms include the Protists and Fungi.
3.2 Size, Shape and Arrangement
Prokaryotes
Different species of bacteria can be distinguished by differences in their morphological
structures, i.e. shape, arrangement and size.
1
,MIB151S: Structures of Prokaryotic and Eukaryotic cell (Microbiology 1)
Cape Peninsula University of Technology
Lecture 3 Notes
Most commonly, bacteria have one of two shapes, cocci (s. coccus) and rod, often
called bacilli (s. bacillus).
Arrangements of cocci
Exist as individual cells
Diplococci: cocci may divide and form
pairs, e.g. Neisseria gonorrhoeae
Long chains: repeated division of cells
in one plane, e.g. Streptococci,
Enterococci, Lactococcus
Clusters: cell divides in random planes
to form irregular grape-like cluster, e.g.
Staphylococcus aureus
Tetrads: cells divide in 2 planes to
form square groups of 4 cells, e.g.
Micrococcus luteus
Cuboidal: cells divide in 3 planes to
form cubes of 8 cells, e.g. Sarcinia
Arrangements of bacilli
Bacilli differ in their length-to-width, with coccobacilli being so short that they resemble
cocci;
The shape of the rod’s end often varies between species – they may be flat ( Bacillus
anthracis), rounded, cigar-shaped, or bifurcated (divided into two branches or forks) ;
Although many rods do occur singly, they may remain together after division to form
chains (Bacillus megaterium is found in long chains).
They may form pairs, i.e., diplobacilli; form chains, streptobacilli, e.g., Bacillus subtilis;
form trichomes, which are similar to chains, with a larger area of contact between
adjacent cells (Beggiatoa, Saprospira).
A few rod-shaped bacteria, the vibrios, are curved to form distinctive commas or
incomplete spirals.
Other forms of bacteria
Actinomycetes (fig. a) characteristically form long multinucleate filaments or hyphae that
may branch to produce a network called a mycelium (Actinomyces, Streptomyces);
2
, MIB151S: Structures of Prokaryotic and Eukaryotic cell (Microbiology 1)
Cape Peninsula University of Technology
Lecture 3 Notes
(a) (b)
(c) (d)
Many bacteria are shaped like long rods twisted into spirals or helices, called spirilla (fig.
b) if rigid and spirochetes when flexible;
The oval- to pear-shaped, Hyphomicrobium (fig. c), produces a bud at the end of a long
hyphae;
Gallionella (fig. d) produce nonliving stalks;
Some bacteria are flat, square to rectangular boxes, e.g., Walsby’s square bacterium;
Some bacteria are variable in shape and lack a single, characteristic form; these are called
pleomorphic even though they may, like Corynebacterium, have generally rod-like form.
Size
Bacteria vary in size and in shape; Average size is 0.5 - 1µm in diameter. E.coli: 1.1 –
1.5µm wide x 2 - 6µm long;
The smallest bacteria is 0.14 – 2µm in diameter;
The largest is 600 x 80µm (Epulopiscium fishelsoni, living in the intestine of the brown
surgeonfish).
3
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller Professor087. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $5.96. You're not tied to anything after your purchase.
Can Stuvia be trusted?
4.6 stars on Google & Trustpilot (+1000 reviews)
67866 documents were sold in the last 30 days
Founded in 2010, the go-to place to buy study notes for 14 years now