Acellular and Prokaryotes Flashcards
Examples of Cellular Microbes?
Bacteria
Archaea
Algae
Protozoa
Fungi
Examples of Acellular Microbes
Virus
Viroids
Prions
Categories of Microbes
Cellular Microbes
Acellular Microbes
Complete virus particles are called?
Virions
It infect humans, animals, plants, fungi, protozoa, algae and bacterial cell.
Virus
It cause specific type of cancer.
Oncogenic Virus or Oncovirus
A typical virion consists of a genome of either
DNA or RNA,
and is surrounded by a _______ (protein coat), which is
composed of protein units called ______.
a. Capsid
b. Capsomeres
Nucleic Acid + Capsid =
Nucleocapsid
5 properties of Viruses that distinguish them from living cells.
a. possess either DNA or RNA, whereas living cells possess both.
b. unable to replicate on their own.
c. DO NOT divide by binary fission, mitosis, or meiosis.
d. lack the genes and enzymes necessary for energy production.
e. depend on the ribosomes, enzymes, and metabolites of the
host cell for protein and nucleic acid production.
Viruses are classified by:
a. type of genetic material (either DNA or RNA),
b. whether the virus nucleic acid is single stranded or double stranded,
c. whether the virus nucleic acid is positive-sense or negative-sense,
d. shape of the capsid,
e. number of capsomeres,
f. size of the capsid,
g. presence or absence of an envelope,
h. type of host that it infects,
i. type of disease it produces,
j. target cell, and
k. immunologic or antigenic properties.
Categories of Viruses based on type of nucleic acid they possess.
a. Doube-stranded DNA Viruses
b. Double-stranded RNA Viruses
c. Single-stranded DNA Viruses
d. Single-stranded RNA Viruses
Steps In the Multiplication of Animal
Viruses.
- Attachment
- Penetration
- Uncoating
- Biosynthesis
- Assembly
- Release
Viirus is able to hide from a host’s
immune system by entering cells and remaining dormant.
Latent Viral infections
Drugs that are used to treat viral infections.
Antiviral agents
This virus causes acquired immunodeficiency syndrome (AIDS).
Human Immunodeficiency Virus (HIV)
Virus that infects bacteria are called _____.
Bacteriophages or simple phages.
2 Categories of bacteriophages.
Virulent bacteriophages
Temperate bacteriophages
It always cause LYTIC CYCLE, which ends with the destruction of bacteria.
Virulent Bacteriophages.
Its DNA can remain integrated into the host cell’s chromosomes for generation after generation.
Temperate bacteriophages.
Summary of the Lytic Process.
- Attachment
- Penetration
- Biosynthesis
- Maturation
- Release
- It is short, naked fragments of single-stranded RNA, which can interfere with the metabolism of plant cells.
- it can be also transmitted between plants in the same manner as viruses.
Viroids
- It is small infectious proteins cause fatal neurologic diseases in animals and humans
- Of all pathogens, _____ are the most resistant to disinfectants.
Prions
Bacteria are divided into three major phenotypic categories:
- Gram-Negative and have a cell wall.
- Gram-Positive and have a cell wall.
- Lack a cell wall (Mycoplasma spp.)
Three basic categories of bacteria based on shape:
- Cocci (round bacteria)
- Bacilli (rod-shaped bacteria)
- Curved and spiral-shaped bacteria
Coccus or round bacteria can be seen as:
Single (Cocci)
Pairs (Diplococci)
Chains (Streptococci)
Cluster (Staphylococci)
Packets of 4 (Tetrads)
Packets of 8 (Octads)
Medically important cocci:
- Enterococcus spp.
- Neisseria spp.
- Staphylococcus spp.
- Streptococcus spp.
Medically important bacilli:
a. Enterobacteriaceae
b. Pseudomonas
aeruginosa
c. Bacillus spp.
d. Clostridium spp.
It cause of relapsing fever, in a
stained blood smear.
Borrelia hermsii
The fixation process serves to:
1) kill organisms;
2) preserve their morphology; and
3) anchor the smear to the slide.
Two Most Common Techniques of Fixation:
- Heat Fixation – not a standardized technique; excess heat will distort
bacterial morphology. - Methanol Fixation – a standardized technique; the preferred method.
Three Major Categories of Staining
Procedures:
- Simple stain - bacterial shape and morphologic arrangement (e.g.,
pairs, chains, clusters) - Structural staining procedures
- Capsule staining
- Spore staining
- Flagella staining - Differential staining procedures
- Gram stain (Gram-Positive /Gram-Negative)
- Acid-fast staining procedures
Bacteria is divided into two major groups:
- Gram-Positive (bacteria end up being blue to purple)
- Gram-Negative (bacteria end up being pink to red)
Gram-Positive bacteria have a _________, making it difficult to remove the crystal violet-iodine complex.
Thicker layer of
peptidoglycan.
Gram-Negative organisms have a ________ making it easier to remove the crystal violet; the cells are subsequently stained with safranin.
Thin layer of peptidoglycan.
With respect to O2, bacterial isolates can be classified as:
- Obligate aerobes
- Microaerophilic aerobes
- Facultative anaerobes
- Aerotolerant anaerobes
- Obligate anaerobes
It require an atmosphere containing molecular oxygen in concentrations
comparable to that found in room air.
Obligate Aerobes
It require oxygen, but in concentrations lower than that found in room air.
Microaerophilic Aerobes
It can survive in either the presence or the absence of oxygen; anywhere from 0% O2 to 20% to 21% O2.
Facultative Anaerobes
It does not require oxygen; grows better in the absence of oxygen, but can survive in atmospheres containing molecular oxygen (such as air and a CO2 incubator).
Aerotolerant Anaerobes
It can grow only in an environment containing no oxygen.
Obligate Anaerobes
Organisms with especially demanding nutritional requirements are said to
be __________.
Fastidious (“fussy”)
As bacteria grow, they produce many waste products and secretions,
some of which are _______.
Enzymes
Many pathogens are able to cause disease because they possess __________________ that damage cells and tissues.
capsules, pili, or endotoxins, or because they secrete exotoxins
and exoenzymes
Laboratory identification of bacteria is moving toward analyzing the
organism’s DNA or RNA – techniques collectively referred to as ____________.
molecular diagnostic procedures
They are bacteria, but they do not
possess all the attributes of typical bacterial cells.
Rickettsias, chlamydias and mycoplasmas
They are the smallest of the cellular microbes.
Myclopasmas
It include purple bacteria, green
bacteria and cyanobacteria; they all use light as an energy source, but not in the same way.
Photosynthetic bacteria
These are bacteria that do not produce oxygen, whereas cyanobacteria do.
Purple and Green Bacteria
Photosynthesis that produces oxygen is called __________.
Oxygenic photosynthesis.
Photosynthesis that does not produce oxygen is called __________.
Anoxygenic photosynthesis.
Archaea means _______.
Ancient
