3 shapes of bacteria
Rod-
Bacilli
Spherical-
Cocci
Spiral-
Spirilla
Chemotrophs and phototrophs
Autotrophs: make their own food
Chemotrophs- obtain energy by the oxidation of electron donors in their environments; energy source is the oxidizing energy of chemical compounds
Phototrophs- obtain energy by capturing protons; energy source is mainly sunl
Binary fission
Asexual reproduction; bacteria grows, replicates DNA, and divides in half producing 2 identical daughter cells
Asexual form of reproduction used by some prokaryotes in which a cell divides into two genetically identical cells
Conjugation
Sexual reproduction; hollow bridge forms between 2 bacterial cells and genes move from one cell to another
Form of reproduction used by some prokaryotes in which the prokaryotic cells attach to each other and exchange genetic material
Bacteria structure
Cell wall
Cell membrane
Cytoplasm
Nuclear material
Capsule- polysaccharide layer secreted around the cell wall by some prokaryotes that prevents the cell from drying out and helps the cell attach to environmental surfaces
Flagella
Pili- hairlike, submicro
Heterotrophs
Eat other organisms or food to obtain energy
Virus structure
Core of nucleic acid- DNA or RNA
Capsid- protein coat surrounds core
Lots of shapes
Specific viruses infect specific organisms
Viruses must invade or infect a living host cell in order to reproduce
Capsid
Protein coat that surrounds the core of a virus
Outer protein layer that surrounds the genetic material of a virus
Lytic cycle
*Virus contacts host cell by chance
*Attaches to surface of cell
*Virus injects its DNA/RNA into cell
*Complete virus particle never enters cell
*Growth and replication:
*Virus's NA (nucleic acid) takes over the cell
*Uses host cell to make copies of its
Lysogenic cycle
*Absorption- the virus finds a receptor site and attaches to the cell
Entry- enzymes dissolve part of cell and DNA or
RNA enters the cel - it is now called a prophage (viral DNA embedded in host's DNA)
*Prophage remains part of DNA of the host cell - may
Lysogenic vs lytic
LYSOGENIC
*Viral DNA merges with cell DNA and does not destroy the cell
*The virus does not produce progeny
*There are no symptoms of viral infection
*Temperate viral replication takes place
LYTIC
*Viral DNA destroys cell DNA, takes over cell functions an
How do bacteria and viruses cause diseases?
Bacteria cause diseases by damaging the cells and tissues of the infected organism directly by breaking down the cells for food or by releasing toxins (poisons) that travel throughout the body interfering with the normal activity of the host.
Viruses caus
Bacterial diseases
Pathogens- disease-causing/producing agent
Causes disease in 2 ways:
*Bacteria breaks down its living cells to use
for food
*Bacteria release toxins that travel through
body
Diseases- Lyme disease, tetanus, tuberculosis, strep throat, tooth decay
Vaccines
Viral diseases
Viral diseases in humans- polio, chicken pox, cold, flu, hepatitis, AIDS, HPV-cancer
Disrupt the body's homeostasis, thus causing disease
Oncogenic viruses- tumor-making - causes cancer in humans and animals
Pathogen
Disease-causing/producing agent
Gram staining positive
Purple
P Purple Positive
Gram staining is important in determining which antibiotic to use
Gram staining negative
Pink
More dangerous
Gram staining is important in determining which antibiotic to use
Bacteriophage
Means "bacteria-eater" = virus
DNA core with protein coat and tail fibers for attachment
Retrovirus
Contain RNA as genetic info
When they infect the cell it produces a DNA copy of their RNA genes
Their genetic info is copied backwards (RNA to DNA, not DNA to RNA)
HIV virus and some cancers
RNA virus, such as HIV, with reverse transcriptase in its core
Decomposer bacteria
They help the environment/ecosystem recycle nutrients
Maintain equilibrium in environment
Help break down dead material
Nitrogen fixers bacteria
Nitrogen fixation- process of converting nitrogen gas into usable form for plants
Human and medical uses of bacteria
Used in production of food and beverages - cheese, yogurt, and pickles
Digest petroleum - cleans up oil spills
Removes waste products and poisons in water
Produces drugs/medicine will uptake foreign DNA
Intestines- E. Coli helps digest food and makes vita
Environmental uses bacteria
Nitrogen fixation
Bioremediation (purify groundwater and contaminated soil)
Decomposers
Fight pollution (oil spills)
Endospore
Dormant bacterial cell able to survive for long periods of time during extreme environmental conditions