Difference between Viruses, Bacteria, and Fungi || pharmacyteach.com

  

Difference between Viruses, Bacteria, and Fungi 

 

 

 

                          

Virus 

   "Viruses are the simplest and smallest living entities/particles which are composed of small numbers of macromolecules i.e. nucleic acids (DNA and RNA ) and proteins. But sometimes glycoproteins and lipoproteins are also funded in virus structure."

• The virus is also known as an obligate parasite ( obligate parasites mean it totally depends on their host). 

• Some viruses have an outer covering called an envelope which is mostly composed of lipoproteins 

• The nucleus, cytoplasm, mitochondria, and ribosomes are all these organelles except nucleic acid and protein are not present in any kind of virus.

• The replication (reproducing) virus must be within any host cells because the virus cannot produce (generate) energy or synthesis proteins by itself.

• The replication method of the virus is different from all other cells ( i.e. Virus does not follow the method of binary fission or mitosis ). Hundreds of progeny viruses can be produced by replication of one virus whereas only two daughter cells by one cell division.

       

• viruses show both the characteristics of a living and a non-living for this reason viruses can consider at the borderline of living and nonliving.

•  Viruses act as non-living when it found in the free atmosphere (outside the host cells ) but when they enter the body of a host ( living organism) then they show the properties of a living organism and start reproduction and generate energy by using the host machinery. 

 

Difference b\t living and nonliving

Properties of virus 

 

living Properties of virus

• Having genetic materials DNA / RNA 
• Presence of an outer protein coat
• Can be replicated ( inside of living cells) 
•   Cause infectious diseases  
•  Able to mutate /evolve                        

Nonliving  properties of the virus 

• Lack cellular structure
• Do not respire
• Do not move and grow in a free atmosphere
• It can be crystallized and stored in a bottle like chemicals.
• Do not have metabolic activity of their own
• Lack of enzymes activity 

 

                                                                                        

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                          Bacteria

     

•  Bacteria are unicellular (means made up of single-cell) prokaryotic organisms.

  

• Prokaryotic organisms are those organisms that do not have a proper nucleus and the genetic materials of that organisms are randomly scattered in their cytoplasm.

 

• Bacteria belong to the prokaryote kingdom so bacteria do not have a well-defined nucleus.

 

• Firstly it was said that all prokaryotic are bacteria but it was cleared by American microbiologist Carl Woese, that not all prokaryotic are bacteria. Carl noted some changes among prokaryotic in their cellular and biochemical characteristics. So based on this, he classified prokaryotic into bacteria and Archaea domain [1]

 

 

• The size range of bacteria from about 0.2 - 5 um .and the smallest bacteria  ( Mycoplasma ) size is the same as the largest virus size   ( poxviruses ) .its means that bacteria are more significant than the virus.

 

• The longest bacteria are rod-shaped the size same as yeast and human red blood cells ( 7 um).
• All the bacteria have cell walls except  " Mycoplasma species ) which have no cell walls, having only a cell membrane. 

 

• The cell wall of most bacteria is composed of " Peptidoglycan ".it provides structural support and maintains the original shape of the cell.

 

• Some bacteria have capsules, Flagella, and pili on the outer surface of the cell wall.

Based on shape bacteria are classified into three groups ;  

1.   Cocci 

2.    Bacilli 

3.   Spirochetes 

• Based on cell call bacteria can be classified into two groups ; 

   1. Gram-positive 

   2. Gram-negative  

   

• the difference between gram-positive and gram-negative cell walls of bacteria is the following ;

 

 

Comparison of the cell wall of gram-positive and gram-negative bacteria ;

Component	Gram-positive	Gram-negative
Peptidoglycan	Thicker ;multilayer	Thinner; single layer
Teichoic acid	Yes	No
Lipopolysaccharide  ( endotoxin )	No	Yes
Periplasmic space	No	Yes
Porin  proteins	No	Yes

 

 

 

 

 

 

 

 

Difference between viruses and bacteria table.                 

                 

Features	viruses	Bacteria
Cause	Causes viral infection	Causes bacterial infection
Living properties	Viruses are not living organisms.	Bacteria are living organisms.
Replication	Required living organism	Can replicate without living organisms.
Contagious	Yes	Maybe
Visibility	Visible under an electronic microscope.	Visible under a light microscope.
Cells	Don’t have cells	unicellular
Spread	Can spread through the body	Stays in one part of the body.
e.g. of infections	Common cold, flu, chicken pox.	Pneumonia, urinary tract infection.
Treat with antibacterial.	No	Yes

                                   Fungi 

Like viruses and bacteria, fungi are also a microorganism and belong to " eukaryotic organisms ".

unlikely bacteria fungal cell wall do not compose of peptidoglycan it consists of "chitin".

 

Due to the absence of peptidoglycan fungi are insensitive to certain antibiotics i.e. penicillins and cephalosporins.

 

The cell membrane of fungi is different from the human cell membrane in such a case that the fungal cell membrane contains " ergosterol " other hand contains " cholesterol ".

 

The diameter of fungi is 4mm and Reproduction occurs by sexual and asexual spores.  

 

 

Difference between Viruses, Bacteria, and Fungi.

 

Features	viruses	Bacteria	fungi
Cells	NO	Yes	Yes
Cell division	Inside the host cell	Inside or outside the host cell	Inside or outside the host cell
Nucleus	Absent	Prokaryotic nucleus	Eukaryotic nucleus
Size	Very small	Bigger than viruses	Bigger than bacteria.
Nucleic acid	Either RNA or DNA	Both RNA and DNA	Both RNA and DNA.
Ribosome	Absent	70s	80s
Diseases	Flu, corona, HIV	TB, Leprosy, pneumonia	Athlete’s foot

Difference between Viruses, Bacteria, and Fungi. Pharmacyteach .com

 

[1]	K. Rogers, Bacteria and Viruses, new york Britannica Educational Publishing, 2011.