Differentiate

Question 1

Differentiate “lysogenic” & “lytic” cycle

Answer 1

Lysogenic cycle
Bacteriophage injects DNA/RNA into bacterium cells to become prophage (dormant state 休眠) → Prophage DNA is copied during cell division → remains in the bacterium for generations (→) can be induced by environmental factors to lysogenic cycle
(host bacterium cell survives and functions normally while harboring the prophage)

Lytic cycle
bacteriophage injects DNA/RNA into bacterium cells → hijacks (takeover) the host’s cell to directly synthesis more phages → assembles within the host cell → produce lysozyme (breakdown the bacterium cell wall - peptidoglycan) → increased number of phages & internal pressure → cell lysis → release new phages into the surrounding environment
(host bacterium cell dies immediately)

Question 2

Differentiate “non-enveloped” & “enveloped”

Answer 2

Non-enveloped
Viral genome is packed within a protein coat called CAPSID

Enveloped
Viral capsid is surrounded by a MEMBRANE LAYER derived from the host’s plasma membrane

Question 3

Differentiate the virus release of “non-enveloped” & “enveloped”

Answer 3

Non-enveloped
- Lyst the host cell and release progeny virions

Enveloped
- Protein insert into host membrane → capsid attaches to the membrane & extrudes (擠壓) → bud off/release

Question 4

Differentiate “antiviral” & “antibacterial/antibiotic”

Answer 4

Antiviral = target VIRUS infection

Antibiotic = target BACTERIA infection

Question 5

Differentiate capsid & capsule

Answer 5

Capsid
@virus
- thick protein layer
- prevent virus from degradation (can live longer even under harsh envir.)

Capsule
@bacteria (some)
- outmost layer
- thick glycocalyx layer (polysaccharides + lipid + protein)
- helps bacteria to evade immune surveillance (監視) → prevent from being phagocytized
- prevent from dessication (乾燥)
- prevent from bring killed by detergent (chemicals)
- prevent from viral infection

Question 6

Differentiate “Empiric” & “Definitive” therapy

Answer 6

Empiric
- broad spectrum antibacterial agent (bacteria/ fungi/ virus/ parasitic)
- base on experience

Definitive
- narrow spectrum of antibiotic
- after identification of the etiologic pathogen