Bio Test 2: Microbio Flashcards
Characteristics of bacteria. All bacteria are
single celled, prokaryotic (lack nuclues and membrane-bound organnelles), reproduce asexually (binary fission), contain DNA made of a single chromosne
Nitrogen fixation
N2 some bacteria take nitrogen directly from the air to make proteins. These bacteria usually live in nodules on roots of legumes. They cna’t use N2 so they make it into usable gasses
Carbon-oxygen cycle
Bacteria are key in the breakdown of dead organisms and the cycling of carbon dioxide back into the atmosphere. Decompose dead organisms=release stored O2 into atmosphere
Production of vitamin K and B12
occurs in humans in the large intestine, eat your waste to create needed vitamins
Size of a bacteria
1 to 10 upm (1000 upm = 1mm)
DNA in a bacteria is not
enclosed in a nucleolus, chromosne lose in cytoplasm
Flagellum
whip-like movement not always present
Plasmid
loop of DNA which is exchanged during conjugation
Cytoplasm in bacteria
contains ribosomes for protein synthesis, factory to make proteins
Capsule in bacteria
reduces water loss, resists high temperatures and protects against antibiotics and viruses, don’t need it but useful
Cocci
round
Bacilli
Rod-shaped
Spirilli
spiral
Staphylo
clusters
Strepto
chains
Diplo
pairs
Mono
individual cells
Naming bacteria
group then shape, can be any combo
Gram-Positive
stained purple after a dyeing technique with crystal violet and iodine, these bacteria have a thick cell wall and are mostly harmless. Strepto coccus
Gram-negative
stained pink these bacteria have a thin cell wall and many are pathogenic, can make you sick but not always. Salmonella
heterotrophic
must eat others for food
autotrophic
able to mkae own food (photoautrophic-sunlight) (chemoautotrophic-chemicals)
Aerobic (Aerobes)
use oxygen to produce energy from food, obligate (need oxygen to survive) or facultative (can switch dependancy on oxygen)
Anaerobic
do not require oxygen to produce energy, can be obligate (will die if exposed to o2)
Binary fission
single circular chromosone replicates, mutations can occur increasing genetic diversity, cell sperates into two cells
Conjugation
occurs when conditions are less than ideal due to shortages of food or space or decreased temperatures. two bacterial cells connect via a brighe (a pilus) and exchange a plasmid (small ring of dna)
2 effects of conjugation
creates variation (genetically differnt_
antibiotic resistant
endospore formation
occurs with gram positive (good) bacteria, when growth conditions become unfavorable the bacterium makes an endospore (thick wall that surrounds its DNA and cytoplasm), the endospore can lie dormant for a long time, through droght, heat and radiation until good contions return
Endotoxins
produced inside bacteria and are only releaeed when gram negative bacteria split they are seldom toxic but do cause fever diarrhea and vomitting, salmonella
exotoxins
produced and excreted from living bacteria they do not produce fevers they are often fatal, clostridium
Are viruses alive
no because they: are not made of cells, don’t need energy, can’t reproduce without infecting a living cell, no homeostasis, can’t die
Characteristics of viruses
all are parasitic and cannot live indpendently
they cannot invade all cell types (e.g. rabies infects mammals, HIV infects only white blood cells)
They must use the energy of other cells to “live” and reproduce, the host cell does everything for then
Size of a virus
0.01 to 0.1 Upm (micrometer)
Strucutre of a virus
nucleic acid core, protein coat (capsid), external proteins
Nucleic acid core
small piece of genetic material, can be DNA or RNA, contains instructions to make more more viruses,
Protein coat (capsid)
exteranl sturucture that contains parts, determines shape of the virus
external proteins
used for recognition, attachment
Bacteriophage
attaches to cell surface and inject their gentic material
animal virus
triggers cell to eat the virus, (endocytosis)
plant virus
through a cell wall injury or when polination occurs
Lytic cycle
Virus attaches to cell and injects DNA into cell, viral DNA uses bactrial cell components to manufacture more viruses, occurs very fast destroys cells viral symptoms are immediate. cell dies as baby viruses break out of the cell
Example: adenovirus 9common cold
Lysogenic cycle
virus DNA combines with cell DNA, occurs slowly viral symptoms are delayed (chicken pox)
when infected cell goes through mitosis the viral also duplicates, something must trigger the virus in order to show signs and start the lytic cycle
Simple RNA viruses
takes over cell functions directy, avoids cell DNA entirely, (influenxa), goest straight to RNA and gives it instructions to make more viruses
Retrovirus
uses an enzyme to rewrite cell DNA with the viral RNA, enzyme makes frequent mistakes thus has a high mutation rate, long, slow life cycle, turns RNA into DNA,
HIV
Cell lysis
virus particles build up inside cell, cell eventually bursts open, cell is completely destroyed, very common, KILLS HOST
exocytosis
virus is exported out of cell, no damage to cell structures, can continue to make virus, flu virus, keeps host alive
How do viruses spread from animals to humans
can develop mutations that help it jump, more close species=faster jumps, mutations to human have to be able to attacht to cell, has to avoid immune system, has to be transmittable
What can we do to limit the emergence of new human viral infections
quarrantine the sick, wear masks, stay away from sick animals
Prions
abnormally shaped proteins, infect and destroy the brain of mammals, are transmittec by eating infected animals, infected fluids, and exposure to contaminated medical devices, NO CURE
Bovine spongiform encephalopathy “mad cow”
due to a prion infection with a long incubation period, leads to changes in loss of motor control and behavioral changes, caused by eating infected feed, considered nearly eradicated globally, can spread to humans through eating contmainated food, causes variant cjd
CJD
caused by a prion infection or genetic mutation leading to prion fomation, spread through: contaminated food, brain tissue grafts, brain electode implants, human growth hormones, cannibalism
first symptom is usually a rapdly progressing dementia, other neurological symptoms develop, fatal withing weeks to months, treated with palliative care
Kuru
prion disease, formerly common among the Fore people of Papua new guinea, funerary cannibalism was practiced to free the spirit of the dead, tremors are a typical early symptom, fatal disease with no treatment, incubation period 10-50 years
Viroids
infectious pieces of RNA, do not code for protein, smaller than a virus, have no capsid/protein coat, are plant pathogens that destroy crops, no treatment, though to function by “turning off” genes
Parasites
live off their hosts to survive, can be caused by different types of organisms: helminths, protozoa, ectoparasites, parasitic fungi, others
Heminths
parasitic worms across 4 phyla, tapeworms roundworms and flukes, most are intestinal parasites, over 12000 species that infect humans, often spread through contaminated water or soil
Protozoa
animal-like protists, spread through insect vector or infected intems, many different infectious agents causing a range of human diseases
Malaria
mosquito-borne disease, caused by members of the genus Plasmodium, prevented by avoiding mosquito bites or medication, simple/uncomplicated malaria can be treated with oral medication, severe/complicated malaria is 10-50% fatal, one of the tragets of Goal 3 of the UNs SDG is to end the malaria epidemci in all countries by 2030
Toxoplasmosis
caused by Toxoplasma gondii, spread by infected food, cat-feces, mother-to-fetus, most people are asymptomatic, many exhibit flu-like symptoms, some people get more serious symptoms and the risk during pregnancy is higher
Ectoparasites
a parasite that lives on the outside of the host, lice, fleas, bedbugs, ticks, mites
ticks
feed off of host blood, can spread many diseases such as:
Lyme disease (can be mild or have serious long-term effects)
Powassan virus (asymptomatic to fatal)
Alpha-gal syndrome (red meat allergy)
fungi
differnet from the decomposer fungi, parasitic fungi attack living organisms, can infect humans (ringworm, athlete’s foot, candidiasis-yeast infections, nail infections)
Surface barriers: Skin
layers of cells-top layers are dead and act as a barrier, live lower layers are supported by immune cells
Keeps water in and pathogens out
Protective features:
-Acid mantle (pH 4.5-6.5), formed by a combination of sebum and sweat makes it hard for some bactdria to reproduce, kills them
-Salts dehydrating to pathogens
-Defeneses, antimicrobial peptides that help prevent infections, upregulate immune responses and trigger repairs
-Commensal bacteria, good bacteria that helps prevent infections by pathogens
Surface Barriers: Mucosa
covers body openings (respiratiory, digestive, reproductive, eyes) with a layer of musus, supported by:
cilia for sweeping, immune cells and antimbodies for active detection and defense
Immune response is less active to limit excess inflamation - keep form overreacting
Lined with commensal bacteria like the skin
Surface Barriers: Tears
able to wash away foregin material, Contains lysozyme: also found in saliva and human milk, able to damage or kill bacteria
Can help repair damage to the eye’s surface
Innate immune system: major functions
identity and remove foreign material, rectuit immune cells with cytokines, activate complement cascade (turn on immune response, can’t be stopped), activate adaptive immunity, participate in creating the surface barriers
cytokines
molecules in blood that send messages
Cells in the innate immune system
Phagocytes, Granulocytes, Natural killer cells
Phagocyte cells
macrophages, dendritic cells, neutrophils (also a granulocyte)
what are the main roles of phagocytes
eating, phagocytosis-cell eating, recruit other immune cells, links inate and adaptive immunity
how do granulocytes aid the immune response
many granuoles in cytoplasm, killing pathogens inject toxins in pathogen, immune signalling, regulate function of other immune cells
what are granuoles
toxic
What is the function of natural killer cells
destroy host cells that are compromised (cancer) or virus-infected, cause cell death by: cell lysis (break cell membrane), apoptosis (programmed cell death), do not need activation by other immune cells
Adaptive immune system: major functions
recognize self and non-self during antigen presentation (showing what ate), generate immune repsonses specific to the pathogen, create and maintain immune memory
T Cells
fight with inject toxins or telling cells to die:
T Helper cells, killer cells, T regulatory cells, T memory cells
B cells
Plasmablast, Plasma cells, regulatory B cells, memory b cells
Where do t cells originate
thymus, at branch of the trachea, very active when you were young
How are memory t cells different from other T cells
cells that live after infection, rember how to fight infection, with you for years, protect you next time
Where do b cell originate
bone marrow, no training
What do B cells use to generate an immmune response
antibody, y shpaed
Antigen
foreign molecules
Antibody
proteins made by B cells, bind to antigen to remove pathogen
Lymphatic system
network of lymphatic vessels, lymph nodes, lymphatic organs, lymphatic tissues, vessels carry a fluid called lymph, site of activation for the adaptive immune system, transport and storage for immune cells, removes excess fluid from tissues, aborbs lipid/fat for the digestive system
Thymus
produces and trains t-cells, most before birth and finishing in childhood, remvoes t cells that cannot bind or signal properly, removes t cells that recgonize self antigens to prevent autoimmune disease
Bone marrow
spongy tissue inside bones, creates blood cells, including immune cells
Spleen
can live withouth, stores B T and red blood cells, contatins macrophage to remove dead/dying immune cells. filter blood, if injured must remove bc of high amount of blood can lead to internal bleeding
Benefits: Infections
fends off pathogenic viruses, bacteria and parasites, barriers innate and aptive immunity all work together, tolerates commensals (good bacteria)
Benefits: damaged cells
T cells can kill damaged human cells, Apoptosi is used regulated process of cell death 50-70 bilion cells a day undergo apoptosis, Phagocytes consume and digest killed cells pieces of them
Benefits: wound repair
phagocytes, remove any pathogens and damaged cells, increase ne blood vessels formation, stimulates extracellular matrix generation, secreted cytokines to attract cells to rebuild tissue
Benefits: cancer
recognizes cancer cells as different, removes these cells, many cancer cells develop ways to evade the immune system, immunotherapy is treatment that uses the immune system
Harms: allergies
harmless antigen(s) cause an immune response, liked to the IgE antibodies, can be a mild nusiance or life threatening (anaphalaxis swelling of airway)
Harms: autoimmune
immune cells do not properly distinguish self vs nonself antigens, immune system attacks your own tissues
Example: celiac-gluten intiates an autoimmune attack, type 1 diabetes-insulin producing cells are attacked, multiple sclerosis-nerve cells are attacked
Harm: immune deficiency
one or more components of the immune system are inactive, some causes: aging, genetic inheritance, HIV infection (kill all cd4)
Supression
malnutrition-impairs the production and activity of immune cells
Stress-suppresses inflammtion and immune cell function
Lack of sleep-reduces cytokine release
Medication-suppression is used to treat autoimmune and autoinflammatory conditons
Boosting
cannot boost you immune system is you’re healthy
8 ways to avoid getting cold/blu when your friends are ill
avoid sick friends, wear a mask, tell them to cover coughs and sneezes, stay 6ft away, hand sanitizer before eating, make sure your immune system is healthy, get the vaccine, hang otu outdoors
3 benefits of bacteria for humans
take nitrogen from the air and make proteins, breakdown decaying matter releasingmore o2 into the atmosphere, creates vitamin k (blood clotting) and b12 (keeps nerves cells healthy)
3 negative consequences of bacteria for humans
can cause infections-bad bacteria in body, create endoxtoxins (fever, diarhea, vomitting), create exotoxins (deadly)
3 benefits of virsues for humans
- Medical Applications (Phage Therapy & Gene Therapy)
Phage Therapy: Viruses called bacteriophages specifically attack harmful bacteria, making them a potential alternative to antibiotics, especially against antibiotic-resistant bacteria.
Gene Therapy: Scientists use modified viruses to deliver healthy genes into human cells, helping treat genetic disorders like cystic fibrosis and sickle cell disease. - Boosting the Immune System
Some viral infections train the immune system to recognize and fight other diseases.
Live vaccines use weakened viruses (e.g., measles or polio vaccines) to stimulate immunity without causing severe illness. - Driving Evolution & Genetic Diversity
Viruses can transfer DNA between species, influencing human evolution.
Some viral genes are incorporated into our DNA and help with essential functions, like the development of the placenta in mammals.
3 consequences of viruses for humans
- Diseases and Epidemics (Makes You Sick)
Viruses like influenza, HIV, and COVID-19 cause widespread illness and can lead to pandemics.
Some viruses cause chronic diseases (e.g., hepatitis B can lead to liver cancer). - Genetic Mutations and Cancer
Some viruses disrupt human DNA, leading to cancer (e.g., HPV can cause cervical cancer, and Epstein-Barr virus is linked to lymphoma).
Viral DNA inserted into human cells can cause harmful mutations. - kull food sources
antibiotics
small compounds that treat infections, treat bacterial diseases
vaccines
dead or inactivated viruses, to provide immunity, prevent viral and bacterial diseases
Pandemic
widespread occurence of an infectious disease over a whole country or world
epidemic
widespread occurence of an infectious disease in a community at a particular time
endemic
regularly occuring disease in an area or community
Whooping cough
bordetella pertusis, Symptoms: violent cough with a whoop at the end, sneezing fever, Transmitted: inhalation of respiratory droplets, contaminated objects, Treatment: antibiotics, Found: whole world, Prevalence: 24.1 million cases a year
COVID-19
SARS-COV-2, fever, chills, sore throat, Transmitted: infected person coughs or sneezes, Treated: taking advil, eat healthy, rest, Found: everywhere, Prevalence: 8,00 per 100,000 in canada
CJD chart
abnormal prions, loss of intellectual and memories, changes in personality, Transmitted: injection, transplant, consumption, Treated: treat symptoms, keep comfortable, Found: europe, americas japan australia, Prevalences: 1 to 2 people million globally
Malaria
Plasmodium (parasites pecios), exteme tiredness, abnormal breathing, when an infected female mosquito bites you or when blood w/ malaria is passed on, Treated: medications that kill the pathogen, iv antimalarial drugs, Found: tropic or subtopic areas of asia, africa, central and south america, Prevalence: 249 million cases a year, 488 cases a year canada
Non-specific immune system defenses
work against all kinds of pathogens, always present
Chemical and physical barriers
skin, sweat, tears, earwax, cilia, acids, coughing, sneezing, and vomiting
Resident microorganism
live on you and prevent invaders from colonizing you
Inflammation
creates a warm, hostile environment for invaders
Immune cells
attack and destroy invaders
fever
the high temperature can kill invaders
Specific immunity
takes thime to devlop but can remember specific pathogens to destroy them, targets different carbs and proteins that are on the surface of a pathogen, antigens trigger white blood cells to destroy the pathogen, antibodies from b cells help target the response
Antigens
targets different carbs and proteins that are on the surface of a pathogen
Different types of vaccines
inactivated, live-attenuated, subunit, recombinant, polysaccharide, conjgate, messenger RNA, toxioid, viral vector
first modern vaccine
made for small pox, a young boy was injected w cow pox which made him immune to smallpox
How vaccines work
they train the immune system about foreing antigens, allow for herd immunity (vaccinate majority of a community)
antibiotics are
medications that kill bacteria
antibiotics are not
effective against viruses fungi or protists
The overuse of antibiotics
over the last few years has been making them less effective, this is called antibiotic resistance. this is why you should take all of your prescribed antibiotics and never take it when not prescribed
Antibiotics are produced by
bacteria or fungi, can be manufactured
What wss the first antibiotic and how was it discovered
penicillin, discovered by accident (fungi in petri dish killed bacteria with penicillin)
Anti viral agent
most target specific viruses, broad-spectrum antivirals are effective against many viruses, do not kill but don’t allow virus reproduction/development, antiviral resistance can develop, used sparingly in high-risk groups and must be administered quickly after disease onset
Antifungal agents
fungi must be treated with fungicides, they can kill or inhibit
antiparasitic agents
used to treat parasitic infections by a number of different parasites, work by destroying or inhibiting the parasite, most are specific to a small groups of closely related parasites
