Tag: cell wall and cell membrane

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Multiple choice botany option b: biotechnology and bioinformatics gram staining microbiology: organisms in industry cell wall and cell membrane
What is the percentage of mucopolypeptide in the cell wall of Gram (+) bacterium?
  1. $60-70\%$
  2. $70-80\%$
  3. $80-90\%$
  4. $90-100\%$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The mucopeptide is a peptidoglycan that is insoluble in nature. It is also called as murein. It is present in almost all bacterial cell walls. However, its percentage is higher in cell wall of gram positive bacteria than in cell wall of gram negative bacteria. 

So, B is the correct answer. 

Multiple choice botany option b: biotechnology and bioinformatics gram staining microbiology: organisms in industry cell wall and cell membrane

Gram negative bacteria detect and respond to chemicals through the receptors in

  1. Muramic acid

  2. Lipopolysaccharide

  3. Porins

  4. Volutin granules
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

It holds receptor molecules that help bacteria detect and respond to chemicals in their surroundings

So, the correct answer is 'lipopolysaccharides'

Multiple choice botany option b: biotechnology and bioinformatics gram staining microbiology: organisms in industry cell wall and cell membrane

Which is not a characteristic of Gram $(+)$ bacteria?

  1. Smooth cell wall

  2. Outer membrane

  3. Prominent mesosomes

  4. Two rings in basal body of flagellum
  5. $70-80\%$ murein in cell wall
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Gram positive bacteria differs from Gram negative bacteria in having multiple layers of peptidoglycan. They have 20–30 nm thick and smooth cell wall. They contain 70-80% murein or peptidoglycan in cell wall. They do not have outer membrane like Gram negative bacteria, which have an outer LPS layer. Due to absence of outer LPS layer, Gram positive bacteria has two rings in basal body of flagellum, one attached to the plasma membrane and one attached to the peptidoglycan wall. They have prominent mesosomes. Mesosomes are folded invaginations of the plasma membrane.

Thus, the correct answer is 'Outer membrane.'

Multiple choice botany option b: biotechnology and bioinformatics gram staining microbiology: organisms in industry cell wall and cell membrane

Which one occurs in the cell walls of Gram (+) bacteria only?

  1. Peptidoglycan

  2. Lipopolysaccharide

  3. Teichoic acid

  4. None of the above
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Teichoic acids are found within the cell wall of most Gram-positive bacteria such as species in the genera Staphylococcus, Streptococcus, Bacillus, Clostridium, Corynebacterium, and Listeria, and appear to extend to the surface of the peptidoglycan layer.

So, C is the correct option. 

Multiple choice botany option b: biotechnology and bioinformatics gram staining microbiology: organisms in industry cell wall and cell membrane

Identify the Gram $(-)$ bacterium

  1. Streptomyces coelicolor

  2. Escherichia coli

  3. Ampycolatopsis orientalis

  4. Bacillus subtilis
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Gram-negative bacteria are bacteria that do not retain the crystal violet stain during gram-staining procedure. Gram positive bacteria are bacteria that retain the crystal violet stain during gram staining procedure. Examples of Gram negative bacteria include Escherichia coli, Helicobacter pylori. Examples of Gram positive bacteria include Bacillus subtilis, Streptomyces coelicolor, Streptomyces orientalis (Ampycolatopsis orientalis).

Thus, the correct answer is 'Escherichia coli.'

Multiple choice botany option b: biotechnology and bioinformatics gram staining microbiology: organisms in industry cell wall and cell membrane

Glycocalyx is

  1. Glycoproteins and glycolipids

  2. Oligosaccharide part of glycolipids and glycoproteins

  3. Lipid and protein parts of glycolipids and glycoproteins

  4. Mucopolysaccharides attached to cell wall.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
  • Glycocalyx or pericellular matrix is a carbohydrate-enriched coating of glycoprotein and a glycolipid that covers the cell membranes of few bacteria, epithelial cells and other cells. 
  • It is mainly used in the recognition of the cell (distinguish between healthy and diseased cells) and also regulates the endothelial vascular tissues.
  • So, the correct answer is 'Oligosaccharide part of glycolipids and glycoproteins'.
Multiple choice botany option b: biotechnology and bioinformatics gram staining microbiology: organisms in industry cell wall and cell membrane

Wall is two-layered in

  1. Mycoplasma

  2. Archaebacteria
  3. Gram $(+)$ bacteria
  4. Gram $(-)$ bacteria
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

On the basis of composition of cell wall, the bacteria are classified into two groups, namely Gram positive and Gram negative bacteria. Cell wall of all bacteria is made up of peptidoglycan. The gram positive bacteria contains thick layer of peptidoglycan. However, Gram negative bacteria contains thin layer of peptidoglycan. Apart from this, it also contains an outer layer of lipopolysaccharide (LPS). Hence, the wall of Gram negative bacteria is two-layered.

Thus, the correct answer is 'Gram (−) bacteria.'

Multiple choice botany option b: biotechnology and bioinformatics gram staining microbiology: organisms in industry cell wall and cell membrane

Cell recognition and adhesion occur due to biochemicals of cell membranes named

  1. Proteins

  2. Lipids

  3. Proteins and lipids

  4. Glycoproteins and glycolipids
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
  • Cell recognition and adhesion occur due to biochemicals of cell membranes name glycoproteins and glycolipids.
  • Glycocalyx or pericellular matrix is a carbohydrate-enriched coating of glycoprotein and a glycolipid that covers the cell membranes of few bacteria, epithelial cells and other cells. 
  • It is mainly used in the recognition of the cell (distinguish between healthy and diseased cells) and also regulates the endothelial vascular tissues.
  • So, the correct answer is 'Glycoproteins and glycolipids'.
Multiple choice botany option b: biotechnology and bioinformatics gram staining microbiology: organisms in industry cell wall and cell membrane

Peptidoglycan (mucopeptide) is found in walls of _____________.

  1. Only Gram +ve bacteria

  2. Both Gram +ve and -ve bacteria

  3. Gram +ve, -ve bacteria and fungi

  4. Bacteria and green algae
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The mucopeptide is a peptidoglycan that is insoluble in nature. It is also called as murein. It is present in almost all bacterial cell walls.

Multiple choice botany option b: biotechnology and bioinformatics gram staining microbiology: organisms in industry cell wall and cell membrane

Glycocalyx is responsible for__________________.

  1. Antigens like those of blood groups ABO

  2. Immune reactions and histocompatibility

  3. Hormone receptors

  4. All the above.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Glycocalyx in eukaryotes (often as part of the cell coat) is involved in cell-cell recognition, immune response, and receptor function. While the term is used differently in prokaryotes, in the context of broader biological questions, it covers these functions.