Microbio Quiz 2

Microbrial DNA Structure and Function

DNA, Nucleotides, histones, chromosomes

Central Dogma of Moelcular biology

DNA→ mRNA→Protein→ Function

Transcription

DNA→mRNA

RNA polymerase is during what

Transcription

What is RNA polymerase function?

During transcription, RNA polymerase binds to the DNA template strand and builds a complementary mRNA molecule.

• This converts the cell’s genetic blueprint into an RNA copy that can be used for protein synthesis

DNA replication is semiconservation

Which means each new DNA has one orignal strand

Helicase function

unwinds DNA

DNA polymerase function

adds nucleotides to the strand

translation transition

mRNA→ protein

In trasnaltion what is a tRNA

It contaisn anticodon that recognizes the codon and carries the maino acid specific for that sequence

polypeptide

ribosome links amino acids

translation ends at ____ codon

stop

Genotype

genetic code

phenotype

expression (proteins, traits) result of genotype

Mutation definition

permanent change in DNA

Kinds of mutations (mechnanisms)

small-scale (point mutations) or Large-scale mutations (chromosomal) mutations

small-scale mutations (point mutations)

insertion, deletion, or subsititon

insertion point mutations

extra bases added

deletion point mutations

baes removed

subsition point mutations

one base replaced with another

large-scale mutations (chromosomal mutations) include

duplication, inversion, translocation

duplication chromosomal mutation

a segment of DNA is compied and inserted

translocation chromosomal mutations

a segment of DNA moves to a new loation, often between chomosomes

inversion chomosomal mutations

a segment of DNA is flipped in orientation

types of outcomes for mutations

silent, missense, nonsense

Silent mutation outcome

Base changes, but amino acid stays the same

missense

(DNA base change → different amino acid is substitutied ex sickle cell, anemia:Glu-Val)

Nonsense mutation outcome

DNa base change creates a stop codon

Causes of mutations

spontaneous (replication errors, base shifts), induced (UV, chemicals, viruses)

Efffects of mutations

can be neutral, harmful (disease), or beneficial (antiobiotic resistance).

Viruses are

Infectious genetic material (DNA or RNA, never both)

Viruses are not

living organisms

Parts of animal virus

spikes, envelope, capside, nucleic acid (DNA or RNA)

• enclosed in a protein coat (capsid)

• some have a lipid envelope with spikes (glycoproteins)

• inside in the nucleic acid (DNA or RNA)

Virus are what kind of parasites

Obligate intracellular parasites; require a host to replicate

Spikes function

Help virus attach to receptors on host cells

Viral life cycle

Attachment

penetration/entry

uncoating

biosynthesis

assembly/maturation

release

Attachment

binds to specific repceptors on the host cell

• lock and key mechanism

penetration/entry

the virus or its genome enters the host cell

uncoating

viral nucleic acid is released

biosynthesis

viral nucleic acid is replicated and viral proteins rae produced

assembly/maturation

new viral particles are sasembled

release

new viruses leave the host cell where replication occurs depends on hte virus

possible outcomes virus

lytic infection, latent infection

lytic infection

virus replicates and kills the cell

latent infection

viral DNA integrates into host genome and remains dormant

how are viruses release

by budding

How does HIV convert RNA to DNA

enzyme reverse trasncriptase

• note trasncription: DNA to mRNA so makes sense that its reverse trascriptase

HIV DNA cant be inserted into host DNA through an ezyme called

integrase

HIV destroys certain immune cells aka

CD4+ helper T cells and leaves patients vulnerable to many infections that can quickly become deadly

When HIV is reactivated can lead to

lysis of T cells

Two major surface proteins in Influenca Virus

Hemagglutinin (H), Neuraminidase (N)

Hemagglutinin (H) Hemagglutinin

binds host receptors (Sialic Acid)

Neuraminidase (N) Neuraminidase Neuraminidase Neuraminidase

Helps release new viruses

Antigenic drift

small mutation produces slihglt ydifferent virus strains → yearly vaccine updates

antigenic shift

gene reassortment, creates anentirely new subtype → pandemics

bacteriophages

viruses that infect bacteria

bacteriophage

virus that that infect bacteria

structure for bacteriphage

capsid head, dna in the capsid head, sheath, contracts to inject dna. baseplate and pins, tail fibers. pin is how they inject their dna from.

how bacteriophage infects bacteria

landing, pining, tailing contraction, dna injection

lysogenic conversion

when a phage incorprorates genes into a bacterial genome that then leads to production of some product so some phages will incorprorate traits in a bacterial cell

pathology

study of diease

Etiology

cause of diase

pathogenesis

how a disease developes

infection

invasion or colonzation of the body by microorganisms, infection does not always lead to disease,

disease

abonormal condition that disrupts normal body function

classification of diseases

1. communicable disease

2. contagious disease: easily spread

3. Noncommunicable:not spread, transmitted person-to-person

4. infectious: caused by pathogens

Duration of diseases

1. acute: rapid onset, short duration (flu)

2. Chronic: long-lasting

3. Latent: inactive, may reactivate (herpes, shingles)

4. 
   

stages of disease

1. incubation period: interval between initial infectiona nd first signs and symtpoms

2. prodromal period: short period after incubation, early, mild symptoms

3. period of illnessL disease is most seere transmission can occur

4. period of decline: signs and symptoms subside

5. period of conalescence: body recoer and return back to norma

6. 1.ncubation

7. prodromal

8. illness the most seere and transmission cna occure

9. decline: symptoms and signs subside

10. convalescence: recovery incubation prodromal illness decline convalescnece incuation prodromal illness decline convalescence

types of infection

local, systemic, sepsis

1. local: confined area

2. systemic: spreads through body

3. Sepsis: microbes/toxins spread in blood

   1. bacteremia: bacteria in blood

   2. toxemia: toxins in blood

   3. viremia: viruses in blood

pimary infection

initial illness, acute infection

secondary infection

after the primary infection weakens body’s defenses, secondary infections can be caused by opportunitistic pathogens

subclinical infection

infections that don’t cause any noticeable illness

reservoir

source where pathogen lives (humans, animals, enironemnt,

zoonoses / zoonotic

diseaes transmitted from animals to humans

human reservoirs (carriers)

may have inapparent infections or latent diseaeses

transmission routes

contact, vehicle, vector

contact trasnmisison

direct (person to person)

indirect (formites)

droplet (sneeze, cough)

congenital (mother to fetus)

vehicle

airborne

waterborne

foodborne

vector transmission

mechanical: passive (flies)

biological: via bite or fluid (mosquitoes, ticks