What do viruses have in common? (3)
surrounded by a protein coat called a capsid, individual proteins are called capsomeres, have either RNA or DNA inside of capsid
How do viruses differ? (6)
Shape, size, some have an additonal envelope that surrounds capsid, a lipid bilayer, membranos, host specific
most are RNA viruses, influenza H1N1, mumps, measles. chicken, pox, herpes, animal viruses
What is the function of DNA/RNA?
code to tell the cell which proteins to make for the virus, has all the info to replicate the virus
What do proteins do?
attach the viruses to the host cells receptors (plasma membrane), 1st line of defense against hosts immune system - enzymes that play role in infection strategy
What are the two kingdoms of bacteria?
Eubacteria- live everywhere, Archaebacteria- harsh enviroments (salty, hot springs, hydrothermal vents, deprived of O2)
What do all bacteria have?
All bacteria have a prokaryotic cell organization because they do not possess a nucleus
Facts about a Gram positive bacterium
simple, stain violet, cell wall made of peptidoglycan, would rather have it
Facts about a Gram negative bacterium
more complex, stain pink, cell wall lacks peptidoglycan, more difficult to treat
What are the steps of a Staining technique?
1. fix the bacteria to the microscope slide using heat (heat fix), 2. Stain with crystal violet stain (rinse with H20), 2. Apply Grahams Iodine (adhere crystal violet if made of peptidoglycan), 4. Rinse with ethyl alcohol (to remove crystal violet), 5. counter stain with safrinin (pink)
What are the different ways that bacteria move?
flagella, lash,shake, or spinalling forward, glide on slime
dominant form, supply of carbon- organic compounds, energy source- organic compounds, examples- E. Coli in gut
supply of carbon- inorganic compounds (co2), energy source- sunlight, examples- cyanobacteria, chemoautotroph- inorganic compounds co2, energy source- from chemical reactions involving ammonia, hydrogen sulfide, nitrates, iron containing substances,
What are obligate anaerobes?
Prokaryotes that do not require 02 or are even killed by 02, they do not conduct respiration but must release energy by fermentation
What are facultative anaerobes?
Prokaryotes that switch between the processes of cellular respiration and fermentation and can survive with or without oxygen, they can live just about anywhere (Ex: e-coli)
Steps of a bacterial cell going through binary fission
1. grow to 2x original size, 2. replicates its DNA (DNA polymerase), 3. divides into 2 cells, 4. produces two identical cells
What is happening in conjugation?
hollow bridge forms gene moves from one cell to another, gene + -, one way transfer of genes, increases diversity
What does a spore do?
survive harsh conditions such as- drying out, extreme heat, lacking of nutrients
Role as nitrogen fixers in Nitrogen cycle
N2 from atmosphere convert to useable form of NH3 (ammonia), for plants & animals, by bacterium root nodules, nitrogen used to make proteins and nucleic acid
What are the four main steps of the nitrogen cycle?
1. assimilation, 2. ammonification, 3. nitrification, 4. denitrification
What are the two reasons pathogenic bacteria are harmful?
1. release toxins (poisonous), 2. damage cells & tissues they infect
How do antibiotics work to stop the bacterial infection?
block growth & reproduction of bacteria, interfere with cell wall building, interfere with with action of ribosomes
Explain the concept of bacterial resistance to antibiotics
occurs through conjugation & mutations resistant bacteria are selected for by misuse of antibiotics
What are the steps of Kochs postulates?
1. isolate a suspicious organism from the blood of a sick animal, 2. grow it in a pure lab culture, 3. inject it into a new host (healthy) and look for signs of the same disease, 4. Re-isolate the organisims from this sick animal to confirm that is it is the same as in step 1
What are the methods of transmission?
Droplet infection, contaminated food/water, direct contact, indirect contact, animal vector,breaks in the skin
Droplet infection, breaks in the skin
coughing or sneezing, respitory illnesses spread this way----wounds, cuts and animal bites
a vector is a go between that isn't sick but carries the pathogen to another host. Mosquitos, ticks, fleas and lice act as vectors
What is the liquid part of blood called? what does it contain?
liquid part = plasma, contains dissoved salts, sugar, antibodies, hormones, and mainly water
What is the cellular part of blood called?
red blood cells (erthrocytes) and white blood cells (leukocytes)
Red Blood Cells
carry oxygen, very numerous, made in the bone marrow, have no nucleus, circulate 4 months then removed by spleen
White Blood cells
have no color until stained, several different types, all function to protect the body from disease
What are Granulocytes?
carry granules full of enzymes to destroy pathogens; have multi- lobed nuclei and are also "eaters"
What are Lymphocytes??
smalles, b cells make y-shaped proteins called antibodies that lock onto specific invaders and destroy them (T-lymphocytes mature in the thymus gland, help b and killer t cells) (b lymphoctes mature in the bone marrow, flag antigens and produce antibodies) (killer t's lyse and kill infected cells using toxics
2nd line of defense
treat all invaders the same, acid & enzymes destroy pathogens, interferon is made by cells to prevent virus replication, phagocytes engulf pathogens, body temp rises to kill pathogens, all inflammatory response
3rd line of defense
specific, create specific weapon and keep weapon for use in future, lymphocytes, b-cells make the antibodies, each is antibody specific for a pathogen
1. exposure o actual pathogen, develop symptoms, build antibodies, recover 2. vaccination- inject weakened or dead pathogen. Advtg- lasting protection, disadvtg- slow
protection results when antibodies are made by another animal and give to a person at risk for developing a disease, advtg- speed, disadvtg- temporary