BIMM 120 Week 1

What is the first law of biology? (thermodynamics)

all life obeys thermodynamics

Why do cells exist in open systems?

material exchange and metabolism

What is the first corollary of the first law of biology? (creation)

temporary creation opposes entropy

What is the secondary corollary to the first law of biology? (equilibrium)

an organism at equilibrium is dead

What is the corollary to the second corollary of the first law of biology? (evidence)

large-scale breaks from equilibrium provide evidence for life

What is the second law of biology? (cells)

all life consists of membrane-encased cells

Why aren’t viruses and plasmids alive?

they cannot reproduce independent

What is the first corollary to the second law of biology? (independently)

only cells can reproduce independently

What is the second corollary to the second law of biology? (programmed)

all life is programmed by genetic instructions

What is the third law of biology? (evolution)

all life arose by evolution

Does natural selection occur at the genotypic or phenotypic level?

both genotypic and phenotypic

What is the first corollary to the third law of biology? (homologous)

all living organisms contain homologous macromolecules from a common ancestor

What is homology?

descent from a common ancestor

What is analogy?

similarity without a common ancestor

What is the second corollary to the third law of biology? (universal)

the genetic code is universal

Why do RNA viruses evolve faster than DNA viruses?

RNA is less stable and DNA viruses can access host proofreading

Have there been any plant viruses that caused epidemics?

no

What is the viral “arms race?”

human immune systems vs. viruses

What proportion of emerging infectious diseases are zoonotic?

75%

What genetic material does SARS-CoV-1 use?

positive single-stranded RNA

How did SARS-CoV-2 make its way to humans?

bats → civet cats → humans

How did MERS make its way to humans?

bats → camels → humans

Why was transmission of MERS relatively limited?

camels are only found in certain regions

What is a notable feature of SARS-CoV-2 relevant to vaccine development?

viral spike (S) protein

What do viral spike proteins bind to?

ACE2 cell surface receptors

How did SARS-CoV-2 make its way to humans?

bats → pangolins → humans

What genetic material does Ebola Virus use?

negative single-stranded RNA

What symptoms are characteristic of Ebola Virus?

hemorrhagic fever

How did Ebola Virus make its way to humans?

bats → primates → humans

What kind of virus is the Marburg Virus?

enveloped RNA filovirus

What symptoms are characteristic of Marburg Virus?

hemorrhagic fever

What are the consequences of the fast mutation rate of Marburg Virus?

fast host range expansion

What kind of virus is HIV?

RNA enveloped lentivirus (retroviral)

Why does HIV have a very high mutation rate?

retrovirus mechanism uses a faulty reverse transcriptase

How did HIV find its way to humans?

primates → humans

What kind of genetic material do influenza viruses use?

negative single-stranded RNA

Why do influenza viruses undergo rapid evolution?

multiple viral chromosomes allow for recombination

What two proteins characterize AIV?

hemagglutinin (H) and neuraminidase (N)

What is hemagglutinin?

viral surface glycoprotein that binds to a host receptor for entry

What is neuraminidase?

cleaves sialic acid for viral exit

Why do we need new vaccines each year for AIV?

fast mutations in surface proteins

What animals does AIV usually infect?

aquatic birds

Why are pigs considered “mixing bowls” for influenza viruses?

pigs have receptors for both bird viruses and human viruses

What are prion diseases?

misfolded and self-propagating proteins

What is BSE?

prion disease in cattle

What is Mad Cow Disease?

human disease originating from BSE

What are Peyer patches?

sites of major prion proteins

Where are Peyer patches in cows?

the entire intestine

What kind of infectious disease do Alzheimer’s and Parkinson’s resemble?

prion diseases

What pathogens often cause foodborne illnesses?

bacteria, viruses, prions, and protozoans

What type of infectious disease do Alzheimer’s and Parkinson’s resemble?

prion disease

What is the most prevalent version of food poisoning?

bacterial

What is gastroenteritis?

long-lasting diarrhea

What kind of bacteria most often causes food poisoning?

gram-negative proteobacteria

What is the primary cause of infant mortality?

E. coli

What bacteria causes typhoid fever?

Salmonella typhi

What causes broad specificity pathogens?

adhesive fimbriae on bacterial surfaces allow for grabbing onto cell surface glycoproteins and glycolipids

What gram-positive bacteria cause food poisoning?

Listeria and S. aureus

What complication is very common in cases of food poisoning?

loss of fluids

What is virus recombination?

when two related viruses inside the same host mix their genetic material and become more virulent

Why is viral food poisoning harder to detect?

viruses do not replicate in food or in cell cultures

What is the primary cause of gastroenteritis in young children?

rotaviruses

What foods often results in infection with noroviruses?

oysters and seafood

What are the two main symptoms of food poisoning?

vomiting and diarrhea

Which type of folding (alpha or beta) represents correct folding?

alpha is correct and beta is incorrect

What causes Alzheimer’s?

aggregate Tau protein causes neurofibrillary tangles

In what two ways can Tau protein spread?

secretion-uptake and cell-to-cell

What are the three most common types of protozoan food poisoning?

Toxoplasma, Cryptosporidium, and Giardia

How did “Beaver Fever” spread?

contaminated mountain stream water

What fixation cycles do prokaryotes participate in?

carbon, nitrogen, and sulfur

What are the three main greenhouse gases?

carbon dioxide, nitrous oxide, and methane

How much worse is nitrous oxide than carbon dioxide?

200x

How much worse is methane than carbon dioxide?

25x

What is antigenic drift?

gradual accumulation of mutations

What is antigenic shift?

exchange of genetic material between different viruses in the same host

What four reasons make bats a common reservoir for zoonotic viruses?

constant interferon expression, low inflammation, relatively long lifespans, and flight-enabled transmission

How did SARS-CoV-1 make its way to humans?

bats → palm civets and raccoons → humans

What aspect of coronavirus replication machinery promotes mutations?

poor proofreading ability of RNA-dependent RNA polymerase

What is the fatality rate of Marburg Virus?

90%

What are two alternative names for the Spanish Flu?

H1N1 and swine flu

What strain of influenza virus are humans not immune to?

H5N1

Where does H5N1 originate from?

cattle

Why isn’t there a universal vaccine for influenza viruses?

too many different strains

What two human viruses circulate among non-human primates?

HIV and Zika

What three kinds of animals have a higher proportion of zoonotic viruses?

bats, primates, and rodents

Where did BSE originate from before becoming Mad Cow disease?

scrapie-like agent in sheep and cattle

How did Mad Cow disease reach and infect humans?

recycling of sheep/cattle waste to feed other cattle

How was spread of Mad Cow disease limited by governments?

banning of certain animal parts from entering the food chain

How did Kuru disease spread?

funerary practice of cannibalism