Chapter 10/16A

Halophiles

-"salt-loving" archaea that live in environments that have very high salt concentrations -need O2 to function -aerobic chemoautotrophs

complex viruses

-Complicated structures -Have a polyhedral capsid with a helical tail attached -"phage" attack bacteria -doesn't attack humans -Ex: Bacteriophages

Thermoacidophiles

-Hot temperature and acid loving bacteria -chemoautotrophic anaerobes (sulfur & hydrogen)

Taxonomy Classification of Viruses

-International Committee on Taxonomy of Viruses (ICTV) -Classified into order, family, genus, and species -Difficult to classify viruses into phylum, kingdom, and domain do to rapid mutating

Virus Structure: Inner core

-Nucleic acid(either DNA or RNA, not both)

Moderate Archaea

-moderate habitat -symbiotic relationship (mutualistic or commensalistic)

Viruses are

-obligate intracellular parasites(require a cell to reproduce and survive) -nonliving -host specific -mutate quickly

Archaea structure

-plasma membrane contains different lipids so they can function at a high temperature -diverse cell walls -no peptidoglycan layer

Virus Structure: Capsid

-protein coat that is hollow -may be surrounded by envelope(made of orgasim cell membrane) -If no envelope virus is naked

lysogenic cycle

1. Attachment to cell 2. Penetration(Introduction to genetic material *3.Integration and Replication- could last months or years *prophase(the cell does regular cell activity while the virus lays inactive) 1. Biosynthesis(when the viral DNA is introduced to cell DNA & starts making viral parts. 2. Assembly(putting viral parts together) 3. Release( the cell lysons & the virus will leave very quickly)

Lytic Cycle

1. Attachment to cell 2. Penetration(Introduction to genetic material 3. Biosynthesis(when the viral DNA is introduced to cell DNA & starts making viral parts. 4. Assembly(putting viral parts together) 5. Release( the cell lysons & the virus will leave very quickly)

Two part system of classifications of viruses

1. Baltimore Classification 2.Taxonomy Classification

Reproduction in Animal Viruses

1. Either attachment or brought into the virus 2. Release of of viral DNA 3. budding 4. lysis of host cell

Transduction in bacteria

1. Phage injects it's DNA 2. Phage enzymes degrade host 3.cell synthesizes new phages incorporate phage DNA and mistakenly some host DNA 4. transducing phage injects donor DNA 5. donor DNA is incorporated into recipient's chromosome by recombination.

Virus facts

1. They can be RNA or DNA but not at the sametime 2.viruses need cells to replicate 3.viruses can change "evolving" 4.viruses cant die they must be destroyed

Viruses are classified by

1. Type of nucleic acid 2. Presence of an envelope (protection and camouflage) 3. Shape 4. Size

Tobacco Mosaic Virus

1. first virus discovered 2. Confirmed Pasteur's idea 3. Viruses are very small

Louis Pasteur

1.A French chemist, this man discovered that heat could kill bacteria that otherwise spoiled liquids including milk, wine, and beer. 2.Suggested that rabies is a virus. 3.named "virus" which means poision

binary fission

A form of asexual reproduction in single-celled organisms by which one cell divides into two cells of the same size

Commensalism

A relationship between two organisms in which one organism benefits and the other is unaffected

Retroviruses

An RNA virus that reproduces by transcribing its RNA into DNA and then inserting the DNA into a cellular chromosome; an important class of cancer-causing viruses.

Methanogens

Archaea that release methane, a greenhouse gas.

Cyanobacteria

Bacteria that can carry out photosynthesis

Gram-positive bacteria

Bacteria that have a thick peptidoglycan cell wall, and no outer membrane. They stain very darkly (purple) in Gram stain.

Gram-negative bacteria

Bacteria that have a thin peptidoglycan cell wall covered by an outer plasma membrane. They stain very lightly (pink) in Gram stain. Gram-negative bacteria are typically more resistant to antibiotics than Gram-positive bacteria.

Aerobic bacteria

Bacteria that require oxygen for survival

Baltimore classification system

Based on genetic material -double strand DNA -single strand DNA -double strand RNA -single strand RNA

Prokaryotes are classified into

Domain Bacteria and Domain Archaea

spherical viruses

Envelope with receptors Ex: HIV, mumps

Antoine van Leeuwenhoek

Father of microbiology 1. First person to recognize bacteria

Give an example of a retrovirus

HIV

Viroids

Infectious particles that cause disease in plants 1. Not a virus 2.Rouge RNA 3.Need a host to reproduce

Eubacteria

Kingdom of unicellular prokaryotes whose cell walls are made up of peptidoglycan

Reproduction in Bacteriophages

Lytic Cycle Lysogenic Cycle

Prokaryote

No Nucleus External structures -cell wall -plasma membrane -capsule(not all) -endospore (protection) -flagella -fimbriae -conjugation pilus(exchange DNA)

Parasitism

One organism benefits and the other is harmed

Photoautotrophs

Photosynthetic bacteria -releases oxygen

Radiation is a frequent method of sterilization. It is effective because it causes damage to DNA. However, prions, the agents that cause diseases such as mad cow disease, are unaffected by these treatments because they lack DNA. What is the defintion of a prion? Why?

Prions contain no nucleic acids, and treatments that normally disrupt these molecules are ineffective.

Reproduction of Retroviruses

RNA based (RNA>viral DNA. The DNA becomes part of the cell) 1. Attachment 2. Entry 3. Reverse Transcript 4. Biosynthesis 5. Assembly 6. Release

Reverse transcription, carried out by retroviruses, is the process by which

RNA information is copied into DNA

Bacilli (bacillus)

Rod shaped bacteria

bacilli bacteria

Rod shaped bacteria

Autotrophic bacteria

Self-nourishing bacteria capable of growing in the absence of organic compounds

Transformation

Taking DNA from a dead cell (endocytosis-the taking in of matter by a living cell by invagination of its membrane to form a vacuole)

Which of the following statements characterizes the lytic cycle of a viral infection?

The cycle typically leads to the lysis of the host cell.

As a result of the lytic cycle, _____.

The host cell's DNA is destroyed, and ultimately, the host cell itself is destroyed in the lytic cycle

In the lysogenic cycle

Viral DNA, incorporated into host DNA as a prophage, is replicated along with host DNA.

antibiotic

a medicine used to save lives because it destroys harmful bacteria and cures infections -Inhibit protein biosynthesis (ribosomes affected) -Inhibit cell wall biosynthesis (peptidoglycan affected)

Methanogens, extreme halophiles, and extreme thermophiles are examples of

archaea

The prokaryotes most likely to be found living in extreme environments such as salt ponds or hot springs are

archaea

Bacteria reproduce by an ____________ process in which one parent cell gives rise to identical daughter cells

asexual (binary fussion)

The capsule and fimbriae function to

attach cells to their substrate or to neighboring cells

heterotrophic bacteria

bacteria that feed on organic material formed by other organisms

Mutualism

both organisms benefit

How do viroids harm the plants that are infected with them?

by altering the plants' growth

facultative anaerobes

can live with or without oxygen

strepto

chains

Straphylo

clusters

Bacteria can quickly acquire new genes in a single generation through

conjugation, transformation, and transduction

The photoautotrophic prokaryotes that generate oxygen as a by-product are the

cyanobacteria

Saprotrophs

decomposers

Dimitri Iwanowsky

discovers viruses with the tobacco mosaic virus

Prokaryotes found inhabiting the Great Salt Lake would be

extreme halophiles (salt-loving bacteria)

One difference between gram-positive and gram-negative bacteria is that

gram-positive bacteria have more peptidoglycan in their cell walls.

helical viruses

hollow, cylindrical capsid (little tube with genetic material inside) Ex: Tobacco mosaic disease

Conjugation, transformation, and transduction are all ways that bacteria

increase their genetic diversity.

Conjugation

is the direct transfer of DNA from one bacterium to another. (sexual reproduction)

Archaea

like extreme conditions (hot or salt) RNA similar to eukarya

The phage reproductive cycle that kills the bacterial host cell is known as a _____ cycle.

lytic

Polyhedral viruses

many sided viruses Ex: cowpox, chicken pox

Which of the following is a member of the domain Archaea?

methanogens

Transduction

occurs when a phage transfers bacterial DNA from one bacterium to another

obligate anaerobes

organisms that cannot live where molecular oxygen is present

By far the most abundant and widespread organisms on Earth are the

prokaryotes

Chemoautotrophs

prokaryotes that use inorganic chemicals as their energy source chemical>energy

Prion

rogue protein particles that cause disease 1. Not a virus 2. Can change host protein 3. Can be dormant 4. Neurodegenerative (holes in the brain)

The lytic cycle of bacteriophage infection ends with the _____.

rupture of the bacterium

Bacteria

single-celled organisms that lack a nucleus; prokaryotes 1. Most numerous organisms

Viroids are _____ molecules and are found in _____.

small circular RNA ... potatoes and other vegetables

Cocci

sphere shaped bacteria

cocci

spherical bacteria

Spirilli

spiral shaped bacteria

Virology

study of viruses

The term for a close association between organisms of two or more species is

symbiosis.

Which of the following statements about treatment or prevention of a prion infection is true?

there is no known treatment or cure for prion infections

Viruses

tiny particles, smaller than bacteria and other pathogens, which must invade living cells in order to reproduce; when they invade, the cells are damaged or destroyed in the process releasing new particles to infect other cells. (much smaller than bacteria)

The pointer is indicating the _____.

viral protein coat (head)

During the lytic cycle, but not the lysogenic cycle

whole viruses leave the host cell to infect other cells