Lab Test 1 Part 2
|what biological molecules can make up the bacterial capsule or slime layer||Capsules are composed of polysaccharides or proteins.|
- 1 What is slime layer made of?
- 2 What type of macromolecule makes up the bacteria capsule?
- 3 What is under the slime layer in bacteria?
- 4 What is capsule or slime layer?
- 5 What are slime producing bacteria?
- 6 How does the bacterial capsule or slime layer contribute to pathogenicity?
- 7 What type of macromolecule is bacteria?
- 8 What is the slime layer that surrounds gram negative bacteria and keeps them from taking up purple stain?
- 9 What macromolecules make up the major part of bacterial cell wall?
- 10 How do bacteria make capsules?
- 11 What is the role of capsules in biofilm formation?
- 12 Why do capsules make bacteria resistant to phagocytosis?
- 13 What is the function of the capsule formed by Bacillus?
- 14 Do all bacteria have a slime layer?
- 15 How is capsule formation influenced by environmental conditions?
What is slime layer made of?
Cellular component – Slime layer The slime layer is an easily removed, diffuse, unorganized layer of extracellular material which surrounds the bacterial cell. It is usually composed of polysaccharides and it may serve to trap nutrients, to aid in cell motility, to bind cells together or to adhere to smooth surfaces.
What type of macromolecule makes up the bacteria capsule?
Most bacterial capsules are composed of polysaccharide, but some species use other materials, such as poly-D-glutamic acid in Bacillus anthracis.
What is under the slime layer in bacteria?
A slime layer in bacteria is an easily removable (e.g. by centrifugation), unorganized layer of extracellular material that surrounds bacteria cells. Specifically, this consists mostly of exopolysaccharides, glycoproteins, and glycolipids. Therefore, the slime layer is considered as a subset of glycocalyx.
What is capsule or slime layer?
Many bacterial cells secrete some extracellular material in the form of a capsule or a slime layer. A slime layer is loosely associated with the bacterium and can be easily washed off, whereas a capsule is attached tightly to the bacterium and has definite boundaries.
What are slime producing bacteria?
The most common infectious agents were Staphylococcus spp. Some strains produce an extracellular polysaccharidic slime that can cause severe infections. epidermidis strains and 61.1% of the S. aureus strains isolated were slime producers and showed icaA and icaD genes.
How does the bacterial capsule or slime layer contribute to pathogenicity?
Capsules contain water which protects the bacteria against desiccation. The possession of capsule makes some pathogenic bacteria resistant to phagocytosis. If glycocalyx is more easily deformed and loosely attached to cell wall it is called slime layer, a well-organized layer, not easily washed off.
What type of macromolecule is bacteria?
The cell wall of gram-positive bacteria is a peptidoglycan macromolecule with attached accessory molecules such as teichoic acids, teichuronic acids, polyphosphates, or carbohydrates (302, 694).
What is the slime layer that surrounds gram negative bacteria and keeps them from taking up purple stain?
In the Gram-negative Bacteria (which do not retain the crystal violet), the cell wall is composed of a single layer of peptidoglycan surrounded by a membranous structure called the outer membrane.
What macromolecules make up the major part of bacterial cell wall?
Peptidoglycan is the major structural polymer in most bacterial cell walls and consists of glycan chains of repeating N -acetylglucosamine and N -acetylmuramic acid residues cross-linked via peptide side chains. Peptidoglycan hydrolases are produced by many bacteria, bacteriophages and eukaryotes.
How do bacteria make capsules?
Bacterial capsules are formed primarily from long-chain polysaccharides with repeat-unit structures. A given bacterial species can produce a range of capsular polysaccharides (CPSs) with different structures and these help distinguish isolates by serotyping, as is the case with Escherichia coli K antigens.
What is the role of capsules in biofilm formation?
The glycosaminoglycan capsule of P. multocida is an essential virulence factor that protects the bacterium from host defenses. Therefore, the negatively charged capsule may interfere with biofilm formation by blocking adherence to a surface or by preventing the EPS matrix from encasing large numbers of bacterial cells.
Why do capsules make bacteria resistant to phagocytosis?
Capsules can resist unenhanced attachment by by preventing pathogen-associated molecular patterns or from binding to endocytic pattern-recognition receptors on the surface of the phagocytes. The capsules of some bacteria interfere with the body’s complement pathway defenses.
What is the function of the capsule formed by Bacillus?
The capsule of Bacillus anthracis, composed of poly-D-glutamic acid, serves as one of the principal virulence factors during anthrax infection. By virtue of its negative charge, the capsule is purported to inhibit host defence through inhibition of phagocytosis of the vegetative cells by macrophages.
Do all bacteria have a slime layer?
All bacteria have a slime layer on their surfaces and when visible under the microscope, they are reffered to as capsule.
How is capsule formation influenced by environmental conditions?
The size of the capsule is influenced by a variety of host and environmental factors that include host tissue location, CO 2 levels, serum, temperature, and the availability of nutrients such as iron and glucose 10, 12.