Chapter 18 biology
What are these viruses: adenovirus influenzia virus tobacco mosaic virus
1. ADENOVIRUS infection causes the common cold 2. INFLUENZA VIRUS is responsible for causing the flu 3. TOBACCO MOSAIC VIRUS causes disease in tobacco leaves
What are the 3 basic shapes of prokaryotes
1. Spherical or round shaped called COCCI/ COCCUS 2. rod shaped called BACILLI/BACILLUS 3. spiral shaped called SPIRILLI/SPIRILLIUM a) also called spirochetes
What are the steps of the lytic cycle?
1. ATTACHMENT a) bacterophage attaches to RECEPTOR SITE b) a virus can't infect a cell without the correct receptor 2 ENTRY: a) baterophage punches a hole and injects its DNA b) plant viruses enters through rips in the cell walls causes by bug holes c) animal viruses enter by endocytosis d) the nucleic acid is injected into the host 3. REPLICATION: a) virus DA takes control of the host's protein synthesis mechanisms b) the viral genes instruct the host cell to make more viral protein capsids and enzymes needed for replication c) viral proteins are made d) viral nucleic acid is replicated e) host's DNA is destroyed f) the virus is using the genetic information already in place in the cell, but changes what is being made g) the virus rely on the host cell for everything because it just has DNA/RNA 4. ASSEMBLY: a) New virus particles are put together b) viral nucleic acid encloses in protein coat c) the protein coat forms around the nucleic acid of new viruses 5. LYSIS AND RELEASE: a) Bacterophage enzyme lysozyme digests the cell wall b) viruses are released by lysis or excytosis in either plants of animals c) these new viruses leave the cell by exocytosis, or by causing the cell to burst or lyse, releasing new viruses that are free to infect other cells d) lysis: destroy the host cell
What are the steps in the lysogenic cycle?
1. ATTACHMENT AND ENTRY: a) the viral DNA inserts or integrates into the host DNA, it doesn't interfere with normal host cell function b) bacterial host chromosome c) virus attaches to bacterial cell d) the viral DNA enters bacterial cell 2. PROVIRUS FORMATION: a) genetic material of virus is incorporated into the host DNA b) once integrated, the infected cell will have the viral genes permanently (provirus) c) Viral DNA becomes part of the bacterial chromosome 3. CELL DIVISION: a) when cell copies, it is also making a copy of the virus b) the provirus gets copied along with the host DNA c) this can continue for years, host cells are not harmed d) viral genes remain inactive until some external stimulus causes the provirus to become active e) dormant viruses may be activated during times of stress, physical, emotional or environmental 4. ACTIVATION RESULTS IN THE LYTIC CYCLE a) the virus enters the lytic cycle b) cell with provirus can go from lysogenic or lytic cycle within its life time c) the provirus can exit the host DNA and enter into the lytic cycle d) Causes by external stimulus 5. REPLICATION: a) the viral genes instruct the host cell to manufacture more viruses b) the bacterial cells makes more viral DNA and proteins 6. ASSEMBLY: a) the new viral particles assemble 7. CELL LYSES, RELEASING VIRUSES: a) the new viruses will leave the cell by exocytosis or by causing the cell to lyse b) new viruses leave host cell c) the exiting of the provirus causes the cell to lyse or viruses can leave by exocytosis
What is the composition of bacterial cell walls?
1. All bacterial cells have peptidoglycan in their cell walls a) peptidoglycan is made of disaccharides and peptide fragments 2. Dyes added to the bacteria identify the two major types of bacteria: a) those with an outer layer of lipids b) those without an outer layer of lipids
What is the most likely theory for the origin of viruses? What is the evidence to support this theory?
1. Although the origin of viruses is not known, scientists have several theories about how viruses evolved 2. One theory, now considered to be most likely, IS THAT VIRUSES CAME FROM PARTS OF CELLS 3. Scientists have found that the genetic material of viruses is similar to cellular genes a) these genes somehow developed the ability to exist outside of the cell
Where are archaea found? What are the groups in the domain archaea?
1. Archaea live in extreme environments are are sometimes called etremophiles a) in extreme environments that are hostile to most other forms of life, archaea predominate 2. Archaea have been found to have some similarities with eukaryotic cells, such as cytoplasm proteins and histones 3. THE 3 GROUPS OF ARCHAEA ARE: a) Thermoacidophiles b) Halophilies c) Methanogens
What are the differences between bacteria and archaea?
1. Bacterial cell walls contain peptidoglcan but archaea do not 2. different lipids in their plasma membranes 3. Different ribosomal proteins and RNA 4. The ribosomal proteins in archaea are similar to those of eukaryotic cells
What is nutrient cycling and nitrogen fixation?
1. Decomposers or detrivores get their energy from the cells and tissues of dead organisms a) Saprobes are decomposers, returning vital nutrients to the environment b) without nutrient recycling, all raw materials necessary for life would be used up c) without nitrogen fixation, far more fertilizer would be needed for growing plants 2. All forms of life require nitrogen a) nitrogen is a key component of amino acids, the building blocks of proteins b) nitrogen also is needed to make DNA and RNA c) Most of Earths nitrogen is found in the atmosphere in the form of nitrogen gas 3. Certain types of bacteria can use nitrogen gas directly a) THESE BACTERIA USE A PROCESS CALLED NITROGEN FIXATION WHICH USES ENZYMES THAT CAN CONVERT NITROGEN GAS INTO NITROGEN COMPOUNDS b) some of these bacteria live in soil 4. Nitrogen-fixing bacteria live in a symbiotic relationship in the TOO NUDULES OF PLANTS SUCH AS SOYBEANS, CLOVER, AND ALFALFA 5. Nitrogen fixing bacteria use the nitrogen in the atmosphere to produce forms of nitrogen the plant can use a) the plants then are able to take up ammonia and other forms of nitrogen from the soil b) these plants are at the base of a food chain, and the nitrogen is passed along to organisms that eat them c) this is why farmers rotate their crops each year so that a crop of legumes can replenish the nitrogen in the soil d) special type called Rhizobium take nitrogen and change it for use by plant 6. A TYPE OF ECOLOGY OF BACTERIA
What are the two domains that prokaryotes are divided into?
1. Domain Bacteria 2. Domain Archaea 3. All prokaryotes were once classified into one group-Kingdom Monera, based on their lack of a nucleus and membrane bound organelles a) However, modern research has shown that great differences exists among prokayotes b) Now they are divided into two domains
How large are prokaryotes
1. Even when using a typical light microscope, prokaryotes are small when magnified 400 times 2. Prokaryotes are typically only 1 to 10 micrometers long and 0.7 to 1.5 micrometers wide 3. Because prokaryotes are so small, nutrients and other substances the cells need can diffuse to all parts of the cell easily a) small cells have a larger, more favorable surface area- to volume ratio than large cells
How do mutations help Bacteria survive?
1. If the environment changes and bacteria are not well adapted to the new conditions, extinction of the bacteria is a possibility 2. Because bacteria reproduce quickly and their population grows rapidly, genetic mutations can help bacteria survive in changing environments 3. Mutations which are changes or random errors in a DNA sequence, lead to new forms of genes, new gene combinations, new characteristics, and genetic diversity 4. If the environment happens to change, some bacteria in a population might have the right combination of genes to allow them to survive and reproduce 5. From the human point of view, this can lead to problems, such as antibiotic-resistant bacteria, which may cause disease and are hard to treat
What are thermoacidophiles
1. Live in hot, acidic environments including sulfur hot springs, thermal vents on the ocean floor, and around volcanoes 2. These archaea thrive in temperatures above 80 degrees C and pH levels of 1-2 (water's pH is 7 and is considered neutral) 3. Some of these archaea cannot survive temperatures as low as 55 degrees C 4. Many are strict anaerobes, which means that they die in the presence of oxygen 5. Found in places like Yellowstone 6. Are extremeophiles
What are halophiles?
1. Live in very salty environments a) extremophiles and archaea 2. Halophiles have several adaptations that allow them to live in salty environments 3. Halophiles are usually aerobic, and some carry out a unique form of photosynthesis using a protein instead of the pigment chlorophyll 4. Found in places like the Dead Sea and the Great Salt Lake
Where are flagella's found in a prokaryotes? What is it?
1. Made of filaments 2. FUNCTION: a) used for movement in some prokaryotes (other prokaryotes move by gliding over a layer of secreted slime) b) help prokaryotes move toward light, higher oxygen concentration, or chemicals such as sugar or amino acids that they need to survive 3. Act like a tail 4. the singular is flagellum
How do mutated prions affect normal prions?
1. Mutated prions can cause normal proteins to mutate a) Come in and influence normal prions to change shape b) protein need certain shape function properly 2. Science doesn't know why this happened or how to get rid of mutated prions
What is the ecology of Bacteria
1. Nutrient cycling and Nitrogen fixation 2. Normal Flora 3. Food and medicines
what is the next step after the virus attaches to the host cell? What are the two ways the host cell is used by the virus to replicate itself?
1. Once the virus successfully attaches to a host cell, the genetic material of the virus enters the cytoplasm of the host 2. In some cases, the entire virus enters the cell and the capsid is broken down quickly, exposing the genetic material 3. THE VIRUS THEN USES THE HOST CELL TO REPLICATE BY EITHER: a) lytic cycle b) lysogenic cycle
What are disease-causing bacteria
1. Only a small percentage of bacteria cause disease like 2. the small percentage of bacteria that cause disease do so in two ways: a) some bacteria MULTIPLY QUICKLY AT THE SITE OF INFECTION BEFORE THE BODY'S DEFENSE SYSTEM CAN DESTROY THEM A) Bacteria is using your tissues as a food source B) in cases of serious infections, bacteria then might spread to other parts of the body b) SECRETE A TOXIN OR OTHER SUBSTANCE THAT MIGHT CAUSE HARM A) the bacteria can cause diseases by making poisons called toxins B) The bacteria that causes botulism secrete a toxin that paralyzes cells in the nervous system C) Bacteria that causes cavities in teeth use sugar in the mouth for energy, and in turn secrete acids that erode the teeth D) TWO TYPES OF TOXIN: ENDOTOXIN AND EXOTOXIN 3. Bacteria can also cause disease in plants, and most plants can become infected a) Such infections can destroy entire crops and have long-ranging consequences on local ecosystems b) for example, citrus canker, a bacterial disease that kills orange trees, has severely impacted the Florida citrus crop and prompted eradication programs
What is the structure of a prokaryote (bacteria)
1. Prokaryotes are microscopic, unicellular organisms 2. They have some characteristics of all cells, such as DNA and ribosomes, but they lack a nuclear membrane and other membrane-bound organelles, such as mitochondria and chlorplasts 3. Although a prokaryotic cell is very small and doesn't have membrane-bound organelles, it has all it needs to carry out life functions 4. PARTS OF A PROKARYOTIC: a) Chromosome b) pilli c) capsule d) flagella e) ribosomes which make proteins for the cell
What are some characteristics that can identify prokaryotes
1. Prokaryotes now can be identified using molecular techniques a) By comparing DNA, evolutionary relationships can be determined b) historically, scientists have identified prokaryotes using SHAPE, CELL WALL AND MOVEMENT
what food and medicines are made with the help of bacteria
1. SOME FOODS MADE WITH THE HELP OF BACTERIA INCLUDE CHEESE, YOGURT, BUTTERMILK, PICKLES, AND IN THE PRODUCTION OF CHOCOLATE a) although bacteria are not found in the chocolate products you eat, bacteria are used to break down the covering of cocoa beans during the production of cocoa 2. Bacteria also are responsible for the commercial production of vitamins, such as vitamin B and riboflavin 3. Bacteria are important in the fields of medicine and research a) although some bacteria cause disease, others are useful in fighting disease b) Streptomycin, bacitracin, tetracycline, and cancomycin are commonly prescribed antibiotics that were originally made by bacteria
Where is the chromosome found in a prokaryotes? What is a nucleoid
1. The chromosomes in prokaryotes are arranged differently from the chromosomes found in eukaryotic cells 2. Their genes are found in the nucleoid a) THE NUCLEOID IS THE AREA OF THE CELL THAT HOUSES A LARGE CIRCULAR CHROMOSOME WHERE THE GENES ARE FOUND 3. Many prokaryotes also have at least one smaller piece of DNA, called a plasmid, which also has a circular arrangement 4. There DNA is a single stranded, double helix
How is the brain affected when infected by prions?
1. The mutated prions infect nerve cells in the brain causing them to burst and result in spaces in the brain a) CJD= holes in space in the brain
What is the structure of a virus?
1. The outerlayer of all viruses is made of protein and is called the capsid 2. Inside the capsid is the genetic material, which could be DNA or RNA, but never both 3. Viruses generally are classified by the type of nucleic acid they contain
What is the size of a virus
1. Viruses are some of the smallest disease-causing structures that are known 2. They are so small that powerful electron microscopes are needed to study them 3. Most viruses range in size from 5 to 300 nanometers (one billionth of a meter) a) it would take about 10,000 cold viruses to span the period at the end of this sentence
What is the metabolism of prokaryotes
1. What process they are using to get energy out of food a) how they use oxygen 2. TYPES OF METABOLISMS: a) Anaerobic prokaryotes do not use oxygen for growth or metabolism b) obligate anaerobes c) facultative anaerobes d) obligate aerobes 3. Beside being classified by how they use oxygen, prokaryotes can also be classified by how they obtain energy for cellular respiration or fermentation
What is streptococcus?
1. a chain of round bacteria (cocci) 2. causes strep throat
What is staphylococcus?
1. a cluster of round bacteria (cocci) 2. causes staph infections 3. staphylococcus aureaus is one of the types that is becoming drug resistant
What is Gram's stain? How does it work
1. a technique that can help identify bacteria with and without an outer layer of lipid 2. this gram stain techinque uses crystal violet (purple) and safranin (red/light pink) stains to differentiate between cells with lipid layer 3. GRAM-POSITIVE bacteria appear DARK PURPLE because they have a large amount of peptidoglycan in the lipid layer 4. GRAM-NEGATIVE bacteria appear LIGHT PINK because the lipid layer has less peptidoglycan 5. Because some antibiotics work by attacking the cell wall of bacteria, physicians need to know the type of cell wall that is present in the bacteria that they suspect is causing illness to prescribe the proper antibiotic
What are the ways in which prokaryotes can reproduce?
1. binary fission 2. conjugation
What are the energy requirements for prokaryotes?
1. how they get food 2. THERE ARE THREE TYPES: a) heterotrophs b) photoautotrophs c) chemoautotrophs
What are Methanogens
1. the third group of archaea a) also extremophiles 2. These organisms are OBLIGATED ANAEROBES, which means they cannot live in the presence of oxygen 3. They use carbon dioxide during respiration and give off methane as a waste product 4. Found in sewage treatment plants, swamps, bogs, and near volcanic vents 5. Thrive in the gastrointestinal tract of humans and other animals and are responsible for the gases that are released from the lower digestive tract
What does a virus use to attach to the plasma membrane of the host and how does this explain why many viruses cannot be transmitted between different species?
1. the virus attaches to the host cell using specific receptors on the plasma membrane of the host 2. Different types of organisms have receptors for different types of viruses, which explains why many viruses cannot be transmitted between different species
How has smallpox been eradicated?
1. the virus that causes smallpox is a DNA virus 2. Outbreaks of smallpox have occurred in the human population for thousands of years 3. A successful program of worldwide vaccination eliminated the disease, and routine vaccination was stopped
What must a virus do in order to replicate
1. to replicate, a virus must enter a host cell
What is CJD/ nvCJD
A DISEASE IN THE BRAIN CAUSED BY PRIONS THAT RESULT IN HOLES LEFT IN PARTS OF THE BRAIN 1. In the mid-1980s, a new variant of CJD or nvCID was discovered in England 2. Scientists do not fully agree on the origin of nvCDJ, but a leading hypothesis is that the prions are transmitted from cattle 3. Abnormal prions can be found in the brains and spinal cords of cattle a) the hypothesis is that if the spinal cord is cut in the butchering process, the prions might contaminate the beef and then be transmitted to humans that eat the beef b) although this mode of transmission is not agreed upon, the United States government has strict regulations concerning the importation of cattle and beef from other countries
What is bacteriophage? What are the parts of the bacteriophage?
A VIRUS THAT INFECTS BACTERIA From top to bottom 1. genetic material (inside the capsid) 2. Capsid 3. tail 4. tail fiber
What is binary fission
ASEXUAL FORM OF REPRODUCTION USED BY SOME PROKARYOTES IN WHICH A CELL DIVIDES INTO TWO GENETICALLY IDENTICAL CELLS 1. Most prokaryotes reproduce by binary fission 2. In this process, the prokaryotic chromosome replicates, and the original chromosomes and the new copy separate a) as this occurs, the cell gets larger by elongating b) a new piece of plasma membrane and cell wall forms and separates the cell into two identical cells 3. Under ideal environmental conditions, this can occur quickly as often as every 20 minutes a) if conditions are just right, one bacterium could become one billion bacteria through binary fission in just ten hours
What are endospores
DORMANT BACTERIAL CELL ABLE TO SURVIVE FOR LONG PERIODS OF TIME DURING EXTREME ENVIRONMENTAL CONDITIONS a) a spore coat surrounds a copy of the bacterial chromosomes and a little cytoplasms (her definition) 1. Bacteria have several mechanisms that help them survive such environmental challenges as a lack of water, a extreme temperature change, and a lack of nutrients 2. The bacteria that cause anthrax, botulism, and tetanus are examples of endospore producers 3. an endospore can be thought of as a dormant cell 4. AN ENDOSPORE MIGHT BE ABLE TO SURVIVE: a) extreme heat b) extreme cold c) dehydration d) large amounts of ultraviolet radiation e) any of these conditions would kill a typical bacterial cell 5. When a bacterium is exposed to harsh environments, a spore coat surrounds a copy of the bacterial cell's chromosomes and a small part of the cytoplasm a) the bacterium itself might die, but the endospore remain b) when environmental conditons become favorable again, the endospore grows, or germinates, into a new bacterial cell 6. Endospores are able to survive for long periods of time 7. Because a bacterial cell usually produces only one endospore, this is considered a survival mechanism rather than a type of reproduction 8. This is what took place in Paseur's experiment a) air carried endospores which causes changes in experiment
What is conjugation
FORM OF REPRODUCTION USED BY SOME PROKARYOTES IN WHICH THE PROKARYOTIC CELLS ATTACH TO EACH OTHER AND EXCHANGE GENETIC MATERIAL 1. the sex pilius is important for the attachment of the two cells so that there can be a transfer of genetic material from one cell to the other 2. In this way, new gene combinations are created and diversity of prokaryote populations is increases 3. this is how plasmids are transferred
What are prokaryotes
MICROSCOPIC UNICELLULAR ORGANISMS THAT LACK A MEMBRANE-BOUND NUCLEUS AND MEMBRANE BOUND ORGANELLES 1. Many scientists think that the first organisms on Earth were prokaryotes a) today, prokaryotes are the most numerous organism on Earth b) they are found everywhere from the depths of the oceans to the highest mountaintops c) some prokaryotes are the only organisms able to survive in hostile environments, such as the water in hot sulfur springs or the Great Salt Lake 2. The word prokaryotes is a Greek word that means before a nucleus
What are bacteria
MICROSCOPIC, PROKARYOTES, MOST ARE BENEFICIAL TO HUMANS AND TO THE ENVIRONMENT, BUT A SMALL PERCENTAGE CAN CAUSE DISEASE a) microscopic organisms that are prokaryotes 1. Bacteria live in nearly every environment on Earth and are important to the human body, industry, and food production 2. Bacteria are the most studied organisms are found almost everywhere except in extreme environments, where mostly archaea are found 3. Bacteria have strong cell walls that contain peptidoglycan 4. Some bacteria have a second sell wall, a property that can be used to classify them 5. Some bacteria, such as the cyanobacteria are photosynthetic
What is a virus
NONLIVING STRAND OF GENETIC MATERIAL THAT CAN NOT REPLICATE ON ITS OWN, HAS A NUCLEIC ACID CORE, A PROTEIN COAT,AND CAN INVADE CELLS AND ALTER CELLULAR FUNCTION a) nonliving strand of genetic material within a protein coat 1. Most biologists don't consider viruses to be living because they do not exhibit all of the characteristics of life a) they have no organelles to take in nutrients or use energy b) they cannot make proteins c) they cannot move d) they cannot replicate on their own 2. In humans, some disease are caused by viruses a) just as there are some bacteria that cause sexually transmitted diseases, some viruses can cause sexually transmitted diseases, such as genital herpes and AIDS b) these viruses can be spread through sexual contact 3. DISEASES CAUSED BY THESE VIRUSES HAVE NO CURE OR VACCINE TO PREVENT THEM a) can't take antibiotics for viruses because it interferes with the cell wall activity but viruses don't have any cell function b) Vaccinations help build up immune system to kill of the virus c) this way the immune system will cure the body, not the antibiotics
What are photoautrophs? What are cyanobacteria?
ORGANISMS THAT CARRY OUT PHOTOSYNTHESIS IN A MANNER SIMILAR TO PLANTS 1. some bacteria are photosynthetic autotrophs 2. these bacteria must live in areas where there is light, such as shallow ponds and streams, to synthesize organic molecules to use as food 3. Scientist once thought that these organisms were eukaryotes and called them BLUE-GREEN ALGAE a) later it was discovered that they were prokaryotes and they were renamed CYANOBACTERIA b) these bacteria, like plants, are ecologically important because they are at the base of some food chains and release oxygen into the environment c) Cyanobacteria are thought to have been the first group of organisms to release oxygen into Earth's early atmosphere, approximately three billion years ago
What are heterotrophs? What is are saprotrophs
ORGANSISM THAT CANNOT MAKE ITS OWN FOOD AND GETS ITS NUTRIETS AND ENERGERY REQUIREMENTS BY FEEDING ON OTHER ORGANISM a) can't synthesize their own food and must take in nutrients 1. some prokaryotes are heterotrophs 2. many heterotrophic bacteria are SAPROTROPHS a) they obtain their energy by decomposing organic molecules associated with dead organisms or organic waste
What is a capsid
OUTER PROTEIN LAYER THAT SURROUNDS THE GENETIC MATERIAL OF A VIRUS
Where is the capsule found? What is it?
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 a) secrete a layer of polysaccharids 1. The capsule has several important functions including a) preventing the cell from drying out b) helping the cell attach to surfaces in its environment c) helps prevent bacteria from being engulfed by white blood cells and shelters the cells from the effects of antibiotics
What is a prior? what are the differences between normal prion and mutated prion
PROTEIN/chemical THAT CAN CAUSE INFECTION OR DISEASE 1. Although disease now believed to be caused by prions have been studied for decades, they were not well understood until 1982, when Stanley B. Prusiner first identified that the infectious particle was a protein 2. Prions normally exist in cells, although their function is not well understood 3. Normal prions are shaped like a coil a) mutations in the genes that code for these proteins occur, causing the proteins to be misfolded b) mutated prions are shaped like a piece of paper folded many times 4. EXAMPLES OF DISEASES CAUSED BY PRIONS: a) transmissible spongiform encephalogpathies (TSE) b) mad cow diease in cattle c) Creutzfeldt-Jakob disease (CJD) in humans d) scrapie in sheep e) chronic wasting disease in deer and elk
What are retrovirus
RNA VIRUS, SUCH AS HIV, WITH REVERSE TRANSCRIPTASE IN ITS CORE a) RNA viruses that contain the enzyme reverse transcriptase and use it to make a DNA copy of the virus 1. CONTAINS RNA INSTEAD OF DNA 2. Retroviruses use an enzyme called REVERSE TRANSCRIPTASE a) lets you do transcription in reverse 3. Made out of RNA so they convert themselves to DNA so they can become a part of the host's chromosome (USE THE LYSOGENIC CYCLE) a) First, the virus moves into the cyctoplasm of the host cell and the viral RNA is released b) in their RNA contains the directions for reverse transcriptase in order to convert themselves into DNA c) Reverse transcriptse synthesizes DNA using the viral DNA as a template d) this viral DNA then moves into the nucleus of the host cells and becomes part of the host cell DNA and remains dormant e) later it can be activated to make an RNA transcript from the viral DNA and make virus proteins 3. HIV and some caner causing viruses are examples of a retrovirus a) HIV is a retrovirus who attacks the main players of the immune system 4. Retroviruses has to infect the cell first, then become DNA, become part of the host chromosome, and wait to be activated 5. STRUCTURE: a) like all viruses, retroviruses have a protein capsid b) surrouding the capsid is a lipid envelope, which was obtained from the plasma membrane of a host cell c) RNA and reverse transcriptase are in the core of the virus
Where is the pili found? What is it?
SUBMICROSCOPIC, HAIRLIKE STRUCTURES THAT ARE MADE OF PROTEIN a) made of protein 1. Found out the outer surface of some bacteria FUNCTIONS: 1. help bacterial cells attach to surfaces 2. serve as a bridge between cells a) copies of plasmids can be sent across the bridge, thus providing some prokaryotes with new genetic characteristics b) this is one way of transferring the resistance to antibiotics c) Specially used for sexual reproduction
What is normal flora?
THE BACTERIA THAT LIVE IN OR ON YOUR BODY AND ARE HARMLESS 1. A type of ecology of bacteria 2. Normal flora are of great importance to the body and have a function of: a) by living and replicating on the body, they compete with harmful bacteria and prevent them from taking hold and causing disease 3. A certain type of bacterium called Escherichia coli (E Coli) lives inside human intestines a) E coli stains can cause food poisoning, but the type that lives in the digestive tracts of humans and other mammals is harmless and important for survival b) THE E. COLI THAT LIVE IN HUMANS MAKE VITAMIN K, WHICH HUMANS ABSORB AND USE IN BLOOD CLOTTING c) In this symbiotic relationship, E coli are provided with a warm place and food with which to live d) In return, the bacteria provide the body with an essential nutrient
What are exotoxin
Toxic substances that bacteria secrete into their environment. produced by some Gram positive 1. causes diseases first compared to endotoxin
What are chemoautotrophs
USE ENERGY FROM INORGANIC COMPOUNDS TO FORM ORGANIC COMPOUNDS FROM CARBON DIOXIDE 1. a second type of bacteria that are autotrophs and do not require light for energy 2. they break down and release inorganic compounds that contain nitrogen or sulfur such as ammonia and hydrogen sulfide, in a process called chemosynthesis 3. Some chemoautotrophs are important ecologically because they keep nitrogen and other inorganic compounds cycling through ecosystems 4. Example: black smoker
What is the lytic cycle?
VIRAL REPLICATION PROCESS IN WHICH GENETIC MATERIAL OF THE VIRUS ENTERS THE HOST CELL'S CYTOPLASM, THE CELL REPLICATES THE VIRAL DNA OR RNA, AND THE HOST CELL IS INSTRUCTED TO MANUFACTURE CAPSIDS AND ASSEMBLE NEW VIRAL PARTICLES WHICH THEN LEAVE THE CELL 1. Viruses that replicate by the lytic cycle produce active infections which are immediate, meaning that symptoms of the illness start to appear one to four days after exposure a) THE VIRUS ACTIVATE IMMEDIATELY, VIRULENT 2. examples of lytic viruses: a) the common cold b) influenza 3. Takes 90 minutes and makes 200 viruses, which infect more cells 4. The organism becomes sick because the cells infected are getting destroyed as viruses exit and cells aren't doing their normal functions 5. In the lytic cycle, the entire replication process occurs in the cyctoplasm a) the viruses' genetic material enters the cell, and the cell replicates the viral DNA or RNA b) the viral genes instruct the host cell to manufacture capsids and assemble new viral particles c) the new viruses then leave the cells
What is the lysogenic cycle?
VIRAL REPLICATION PROCESS IN WHICH VIAL DNA INSERTS INTO THE HOST CELL'S CHROMOSOME MAY REMAIN DORMANT AND LATER ACTIVATE AND INSTRUCT THE HOST CELL TO PRODUCE MORE VIRUSES 1. virus is dormant for a period of time, TEMPERATE VIRUS 2. Viruses that replicate by lysogenic cycle causes LATENT infections, when the viral DNA enters the nucleus it is inactive/dormant 3. Many disease-causing viruses have lysogenic cycles a) Herpes simplex I A) this virus is transmitted orally, and a symptom of this infection is cold sores B) when the viral DNA enters the nucleus, it is inactive C) it is thought that during times of stress, whether physical, emotional, or environmental, the herpes genes becomes activated and the production of viruses occurs b) HIV c) Shingles 4. In the lysogenic cycle, the viral DNA inserts into a chromosome of the host (nucleus) a) many times, the genes are not activated until later b) then the viral DNA instructs the host cell to make more viruses
What is the plasmid
a smaller circular piece of DNA that doesn't carry directions for the functions of bacteria, may carry antibiotic resistance genes
what is the receptor site
a specific site the virus recognizes and can attach to on the host cell
what is reverse transcriptase
an enzyme that transcribes DNA from the viral RNA in retroviruses
what is a provirus
genetic material of virus is incorporated into the host DNA
what is facultative anaerobe?
organisms that can grow either in the presence of oxygen or without it 1. type of metabolism of prokaryotes 2. example: E. Coli
What is obligate anaerobes?
organisms that cannot live or grow in the presence of oxygen and obtain energy through fermentation 1. type of metabolism of prokaryotes
What is obligate aerobes
organisms that require oxygen to grow 1. type of metabolism of prokaryotes
What is endotoxin?
toxic substances made by Gram negative bacteria, such as E. Coli, not released until the cell dies 1. Cause diseases