Chapter 5: Microbiology Flashcards
Viruses are ____________________ parasites, where they are only able to reproduce within cells
Obligate intracellular parasites
Viruses can’t ______________________ on their own they need a host body
Reproduce
Viruses may contain either ________ or RNA that is either single or double-stranded & is either linear or circular
DNA
What factor affects viruses regardless of the nucleic acid use as its genome?
Size (thier exterior shell is a fixed size & doesn’t expand)
Bacteriophage
Is a virus that infects bacteria & its host
Caspid
Is a protein that surrounds the viral nucleic acid genome (helical capsids are rod shape & polyhedral capsid are multiple sided geometric figures)
A viral genome is located within the capsid ________
Head
The tails & base plate of a virus does what?
Attach to the surface of the host cell
The sheath (middle part of the virus) does what?
Contracts using the energy of stored ATP, injecting the genome into the host
The viral capsid is composed of protein, while the viral genome is composed of _______________
Nucleic Acid DNA or RNA
Animal viruses have an _________ that surrounds its capsid & they achieved it by a process called budding through the host cell membrane
Envelope
Naked viruses
Viruses that don’t have an envelope (all phages & plant viruses)
Basically describe the process of how the virus commands the host cells to reproduce the virus
The first step is binding to the exterior of a bacterial cell in a process called attachment )or adsorption) then the next step is injection of the viral genome into the host cell in a process called penetration (eclipse) & then after that the phage goes into either one of its cycles
What are the two types of phage life cycles?
- Lytic cycle
- Lysoengenic cycle
Describe the steps that occur in the lytic cycle
- Attachment of phage to E. coli & injection of phage chromosome
- Breakdown of bacterial chromosomes by phage-specific enzyme
- Bacterial chromosomes has totally broken down
- Replication of phage chromosome using bacterial materials & phage enzymes
- Expression of phage genes to produce phage structural components
- Assembly of progeny phage particles
- Release of progeny phage by lysis of bacterial wall
What are the steps in the lysogenic cycle?
- The phage binds to the bacterium
- The phage DNA enters the host cell
- The phage DNA integrates & becomes a noninfective prophage
- Chromosome with integrated prophage replicates
- In rare cases the prophage may separate & the cell will be induced to lyse
Many animal viruses go through the same process as regular viruses of attachment, penetration, & injection, however animal viruses enter the cell through _______________
Endocytosis (process where the host cell engulfs the virus & internalize it)
Many animal viruses go through the same process as regular viruses of attachment, penetration, & injection, however animal viruses enter the cell through _______________
Endocytosis (process where the host cell engulfs the virus & internalize it) & its uncoated inside the cell
Animal viruses can goes through the lytic, lysogenic, or the ___________________________
lytic -like (productive cyle)
The productive cyle is like the lytic cycle but it doesn’t _____________ the cell
destroy
In the animal virus lysogenic cycle the dormant form of the viral genome is called a ___________
Provirus
+ RN Viruses (single-stranded RNA genome) must encode __________________________ RNA polymerase to copy RNA genome for viral replication
RNA-dependent RNA polymerase
- RNA viruses must carry ________________________ RNA polymerase (also encodes it too)
RNA dependent RNA polymerase
Retroviruses
Must encode reverse transcriptase
Double-stranded DNA viruses
Often encode enzymes required for dNTP synthesis & DNA replication
What is a prion?
A prion is a misfolded disease-causing protein, as subviral particles, prions are not living but can cause nearby proteins to fold into incorrect conformation
What is a Viroid?
A viroid is a disease-causing molecule of single-stranded RNA. The smallest of the subviral particles viroids generally infects plants & alters transcription of their genes
Gram positive stains what color?
Purple
Gram negative stain what color?
Pink
The ____________ in bacteria makes the bacteria ore difficult for immune system cells to eradicate
Capsule
A bacterium which has one or more flagella is said to be ________
motile
Bacteria may be _______________ meaning they have a flagellum at only one end
Monotrichous
Bacteria can be ________________ meaning they have a flagellum at both ends
amphitrichous
Bacteria can also either be _____________ meaning they have multiple flagella
peritrichous
______ are long projections on the bacterial surface involved in attaching to different surfaceswhere the sex pilius is a special pilius attaching F+ (male) & F- (female) bacteria to facilitate the formation of conjugations bridges
Pili
What are mesophile bacteria
Moderate temperature loving bacteria (30C)
What are thermophile bacteria?
Heating loving bacteria (100C)
What are psychrophiles bacteria?
Bacteria that thrive in low temp (oC)
What are the four types of bacteria?
- Chemoautotrophs
- Chemoheterotrophs
- Photoautotrophs
- Photoheterotrophs
Chemoautroptrophs bacteria
Build organic macromoleucles from O2 using the energy of chemicals
Chemoheterotrophs bacteria
Require organic molecules such as glucose made by other organism as their carbon source & for energy (humans)
Photoautrophs bacteria
Use only CO2 as a carbon souce & obtain their energy from the sun
Photoheterotrophs bacteria
Get their energy from the sun
