bio viruses & bacteria

smallest are smaller than ribosomes

viruses

are smaller than bacteria

viruses

not cells,therefore not living

viruses

no growth

viruses

no metabolism

viruses

no homeostasis

viruses

no ability to make own proteins

viruses

made up of nuliec acid (DNA or RNA)

viruses

virus surrounded by protein coat (protective layer)

capsid

covering around capsid

envelope

comes from host cell membrane (cell that gets virus)

envelope

some have spikes are used for attachment for host cell (spikes =protein)

envelope

high mutation rates in spike genes

rhinovirus(common cold) % influenza virus(flu)

as _ mutate, viruses can escape host immune systems

spikes

since each one slightly different spikes looks completely new to your immune system

why do i get infected by colds & flu over & over?

are protein

spikes

many shapes & sizes

viruses

viruses are obligate intercellular parasites. this means can only reproduce inside host cell

reproduction:

to reproduce

virus only goal

some r broad based others r narrow broad based means can infect many species.

virus host range

influenza a can infect pigs, humans, horses, birds

virus host range

can infect many mammals

rabies

means can infect one or few species

narrow based

r viruses that infect bacteria, & have very limited host ranges

bacteriophages

usually tissue specific

viruses

HIV infects special type of white blood cell called…

helper-T cell

using lytic or lysogenic cycles

reproduction occurs

results in death of host cell

lytic cycle:

virulent viruses

lytic cycle:

replication of viral parts without destroying host cell

lysogenic cycle:

can “hide out” and remain dormant for years

lysogenic cycle:

temperate viruses ex:herpes,simplex viruses

lysogenic cycle:

virus recognizes & attaches to receptor sites on host cell membrane

lytic cycle (AERAR) first step attachment

an enzyme released by virus weakens host cell membrane

lytic cycle (AERAR) second step entry

viral dna enters host cell & leaves capsid behind

lytic cycle (AERAR) second stage entry

virus takes control of host cells machinery to make viral proteins & replicate viral DNA

lytic cycle

(3) replication

viral DNA & proteins come together

lytic cycle

(4) assembly

viral enzymes cause host cell to disintegrate & newly formed viruses (virions) are released (lysis)

lytic cycle

(5) release

(1) attachment

(2) entry

lysogenic cycle first two parts

viral DNA joins the lost cell DNA & forms a prophage (provrius in humans)

lysogenic cycle

(3) integration

prophage is replicated as host cell goes through cell division

lysogenic cycle

(4) cell multiplication

exposure to radiation or certain chemicals causes prophages to become virulent (capable of causing disease) & enter lytic cycle

lysogenic cycle

(4) cell multiplication

contains DNA

virus types

(1) DNA viruses:

usually replicates in nucleus of host cell

first virus type DNA viruses

most vaccines for this type bc of stability

first virus type DNA viruses

ex of this virus: postviruses, herpes, viruses, hepatitis B

first virus type DNA viruses

contains RNA (no DNA)

second type of virus RNA viruses

usually replicates in the cytoplasm of host cell

second type of virus RNA viruses

high rates of mutation bc they lack proofreading capabilities

second type of viruses RNA viruses

harder to treat

second type of viruses RNA viruses

ex of this virus: HIV,measles,influenza,ebola, covid-19

second type of virus RNA viruses

unicellular for (1 cell) organisms

bacteria

microscopic

bacteria

prokaryotic

bacteria

belongs to 2 kingdoms

bacteria

:archaebacteria (harsh environments)

bacteria first kingdom

eubacteria (bacteria we know)

bacteria second kingdom

found on most surfaces

bacteria

bacilli

bacteria rod shaped

cocci

bacteria sphere shaped

sprilla

bacteria sprial shaped

strepto

bacteria chains

staphlyo

bacteria grapelike clusters

diplo

bacteria in pairs

streptococcus

long chains of circular bacteria

staphylobacillius

grapelike clusters of rod shaped bacteria

diplococcus

two circular bacteria

binary fission

how do bacteria reproduce

process by bacterial cell divides itself 2 identical copies

binary fission

DNA copies itself & 1 cell splits into 2 cells

binary fission

over 90% bacteria have this

cell wall

surrounds cell membrane

cell wall

protects bacteria from hostile environment

cell wall

protects bacteria from antibiotics

cell wall

some bacteria may have variety other structures may aid in their existence (capsule, slime layer, pili, etc)

cell wall

made of protein & helps bacteria move

flagella

contains pilus, capsule, cell wall, plasma membrane, nucleiod (DNA), cytoplasm, ribosomes, flagellum

bacteria

feed on dead & decaying material

bacteria living conditions

saprophytes:

often found in soil

bacteria living conditions

saprophytes:

use sunlight as energy source

bacteria living conditions

photoautotrophs:

cannot survive in presence of oxygen (ex: clastru)

bacteria living conditions

obligate anaerobes:

can live w or w/o oxygen (ex: escheri)

bacteria living conditions:

facultative anaerobes:

cannot survive w/o oxygen (ex:mytobacterium, tyberculosis,) lives in lungs &

bacteria living conditions

obligate aerobes:

many are even helpful

are all bacteria bad

helps to digest food

are all bacteria bad

allows to make things, very important to decompose,

are all bacteria bad

pathogenic E.coli

what are common pathogenic (bad) bacteria?

found in ground beef, contaminated fruit & vegs

what are common pathogenic (bad) bacteria?

pathogenic e. coli:

found in raw meats, poultry, eggs, sprouts, fruit & vegs

what are common pathogenic (bad) bacteria?

salmonella:

causes TB, which kills 2 million people annually

what are common pathogenic (bad) bacteria

mytobacterium tuberculosis:

some capable of causing disease. ex: viruses, bacteria

infectious disease control

pathogen:

air, contact, food & water, sex

way pathogens are transmitted

other organisms (ex: mosquitoes) these r referred to as vectors

ways pathogens are transmitted

white blood cells attack & kill pathogens & cells infected w pathogens

how bodies fight pathogens?

special types of white blood cells produce antibodies

how bodies fight pathogens?

r proteins that recognize foreign invaders

antibodies:

r different 4 each different type of pathogens

antibodies:

bind to pathogens, deactivating them, wbcs engulf the pathogens

antibodies:

you can have memory wbcs which stay in your body forever to remember the pathogen for next time.

antibodies:

1.antiviral drugs

2.vaccinations

prevention & treatment

2 main ways to control viral diseases: