what are viruses?
a particle of nucleic acids, proteins, and lipids that invade living cells and reproduced. they are considered parasites because they need a host to live
examples of viruses
influenza, chicken pox, Ebola, malaria, AIDS
viruses have different…
shapes, sizes, and specificity
what are retroviruses?
viruses made of RNA that is then copied to DNA
types of viral reproduction
lytic infection & lysogenic infection
lytic infection
the virus enters a cell, makes copies of itself, and causes the cell to burst
ways to control viruses
vaccines, interferon, antibodies
vaccines
small injected dose of the virus causes the body to have an immune reaction to prevent later infection
interferon
proteins that attach to your cell and prevent viruses from reproducing
what are bacteria?
single-celled prokaryote organisms with no nucleus
how to bacteria reproduce?
through binary fission
bacterial appendages
pilli are the small hair-like proteins used for attachment
the flagellaares used as a motor to move the bacteria
glycocalyx
sugarcoat that protects and prevents drying
cell shape is determined by…
the genetic code of the bacteria. this allows for genetic ID
bacterial cell membrane
regulates what moves in and out of the cytoplasm
plasmid
extrachromosomal DNA is not a part of the genome with different DNA
around how long have archaea existed?
around 3.5 billion years
are archaea heterotrophs or autotrophs
they are producers who make their own food so they are autotrophs
carbon fixation
the process that converts gaseous carbon dioxide to solid carbon compounds
what types of environments do archaea live in?
extreme or adverse conditions
what is the cell wall of archaea made from?
glycoproteins and polysaccharides
how are they different from other bacteria?
16S rRNA and 18S rRNA sequences were totally different in archaea from other bacteria
similarities between archaea and bacteria:
both reproduce through binary fission
they are unicellular organisms
differences between archaea and bacteria:
there are no pathogenic archaea
they have no peptidoglycan in their cell walls
genetically different due to ribosomal and rDNA differences
what is a protist?
mostly single-celled eukaryotes some are multi-cellular
three categories of protist
Animal-like, Plant-like, Fungus-like
about animal-like protist
called protozoans
are heterotrophs
can move to get food
made of cells with a nucleus and no cell wall(like animals)
unicellular
what are the four animal-like groups of protists?
Sarcodines, Ciliate, Flagellates, Parasites
sacrodines
feed using their fake feet or pseudopods
they have a contractile vacuole that takes and expels water
ex. an amoeba
ciliates
uses cilia, which are projections that move in a wave-like motion to move the cell, to eat
ex. paramecium
flagellates
use a flagella, or whip-like tail structure, to move
ex. peranema
parasites
feeds on the body fluids and bodies of their slows
ex. plasmodium(causes malaria)
plant-like protists
commonly known as algae
autotrophic
unicellular and multicellular
there are 7 main types
7 types of protists
Algae, Diatoms, Dinoflagellates, Euglenoids, Red Algae, Green Algae, Brown Algae
algae
most live in water or damp surfaces
some contain chlorophyll to photosynthesize
diatoms
unicellular organisms that have glass-like cell walls
floats on surfaces of bodies of water
used in scouring products
dinoflagellates
unicellular
have two flagella
responsible for red tides
euglenoids
can be autotrophs or heterotrophs
unicellular an green in color
uses flagella for movement
red algae
multi-cellular seaweed
contains red chlorophyll, only needs a small amount of sunlight
green algae
unicellular, multicellular, or colonial
closely related to plants
brown algae
seaweed with many pigments
contains many plant-like structures
fungus-like protists
heterotrophs
have cell walls
they use spores to reproduce
there are two main types
slime mold
brightly colored
lives in moist environments
can be very small or as big as several meters
water molds and downy mildews
most live in water
they grow in tiny threads that look like fuzz
lysogenic infection
The virus replaces parts of the cell’s DNA with the virus’s DNA causing the cell to produce the virus. kills the cell after a prolonged period because it may remain inactive in the cell