Microbiology lecture Exam 1

The suffix "-phile" means:

"loving"

What happens to *most of the Tamiflu* a patient takes?

*80%* is *peed out*.

The Gram Stain is able to stain bacterial cells differently depending upon the structure of their cell wall. Which of these will stain purple and be Gram positive?

*B*

How does *HPV* lead to *cancer*?

*Contains specific enzyme that interrupts cell mutation repairs.* The immune system of the person with HPV prevents the virus from doing serious harm, but the virus can survive for year. Eventually, the virus can lea to the conversion of normal cells on the surface of the cervix into cancerous cells (cervical cancer).

RNA polymerase uses _________________ as a template to synthesize ______________.

*DNA* ; *RNA*

Why does *H5N1 (bird flu)* have a higher death rate but lower transmission rate than *seasonal flu (H1N1)*?

*H1N1* spreads more easily because it lives in the upper respiratory and spreads when the patient coughs or sneezes- the molecules go into the air.

Refer to #27: What kind of virus uses this pathway?

*HIV*

Describe the *phases* of bacterial growth *curve* and what happens in each:

*Log phase*- no growth. Log/*Exponential phase*- bacteria doubles at a constant rate. *Stationary phase*- rate of bacterial death = cell division. *Death Phase*- equals rate of division.

What is the *most contagious virus* known?

*Measles*

Do we have *"cures"* for *viral illnesses*, in the same way we have antibiotics for bacterial ones?

*No*

What happened in *1918*?

*Spanish flu* outbreak Awan --> Human

A bacterial cell is a prokaryote.

*True*

A gene is the piece of DNA that codes for a specific protein.

*True*

Because DNA gyrase is an enzyme used by bacteria, but not humans, we can use antibiotics that interfere with the DNA gyrase enzyme to halt bacterial growth.

*True*

Both prokaryotes and eukaryotes have ribosomes.

*True*

In viruses, the genetic material may be RNA, which may be double stranded or single stranded.

*True*

It is possible for a treatment like Tamiflu to be a selective pressure, selecting for Tamiflu-resistant flu strains to spread.

*True*

You are a eukaryote

*True*

RNA polymerase is the enzyme which:

*builds RNA*

An mRNA molecule is read in sections of 3 bases (like AGC or AUG) that are called _____________.

*codons*

What is it called when an enzyme loses its *shape permanently*?

*denaturation*

The growth of bacteria is said to be ________________:

*exponential*

A prokaryote is the same as a human cell

*false*

Eukaryotes can synthesize proteins much faster than prokaryotes can.

*false*

Once a patient has chicken pox, they rapidly produce antibodies, which destroy all virus particles and they will never be affected by this virus again.

*false*

Prokaryotic ribosomes are exactly the same as eukaryotic ribosomes, so we cannot use antibiotic drugs that target just one or the other type of ribosomes

*false*

Ringworm is a parasite infection caused by a type of roundworm.

*false*

Since bacteria do not have membrane-bound organelles, the reactions that occur in eukaryotes in organelles (like aerobic respiration or photosynthesis) can't happen in bacteria.

*false*

We currently have very effective cures for the flu.

*false*

What causes *ringworm*?

*fungal infection* caused by mold like *parasites*.

What does *ivermectin* act against?

*helmiths (parasitic worm)* - worms in general.

*Ebola* is a hemorrhagic virus.

*hemorrhagic* means it interferes with blood clotting system to cause internal bleeding and blood clotting.

What *conditions* can cause this to happen?

*increase* in temperature or *acidity (pH)*.

The information carried by DNA is used to create ___________, which then moves to the ribosome for protein synthesis.

*mRNA*

What is the definite host of the *malaria parasite*?

*mosquitos*

What is meant by the term *"obligate aerobe"*? (break it down: what does *obligate* mean? what does *aerobe* mean?

*obligate* means to hold or to bind (obligation). *aerobe* means that it needs oxygen. *the organism needs oxygen*

How do Jams and Jellies work to *"preserve"* fruit from bacterial growth?

*osmotic pressure change* The excess sugar removes moisture making it more difficult for bacterial growth.

What does it use as it's *ultimate electron acceptor*?

*oxygen*

Regarding the question above: What is the *parasite name*?

*plasmodium* (sp)

This picture is of an enzyme, which is part of the ______________ group of macromolecules and is composed of chains of _________________.

*protein* ; *amino acids*

What is the "grandmother" of anti protozoan medicines, originally for malaria?

*quinine*

Match the following terms about how new viral strains are made:

*selection*- a treatment becomes a pressure ensuring that resistant strains survive and are passed on to other hosts *antigenic drift*- small mutations in surface proteins *antigenic shift*- recombination or reassortment.

Refer to #27: What types of molecules can be fermented?

*sugars/carbohydrates* - breaks down sugars to make acids

The matching anticodon is found on:

*tRNA*

The process of making mRNA from DNA is called:

*transcription*

The process of making proteins from the information in mRNA is called:

*translation*

What is the difference between an unsaturated fat and a saturated fat, as we discussed in class?

*unsaturated fat*- does not have as many hydrogens around the carbon chain and they are liquid at room temperature. *saturated fat*-has carbon chain surrounded by hydrogens and it solid and room temperature.

The difference between seasonal flu (H1N1) and avian flu (H5N1) is that:

- H5N1 affects the lower respiratory system, and is therefore more deadly. - H5N1 causes cytokine storms, and usually H1N1 does not. - H1N1 affects the upper respiratory system, and is therefore more easily spread by coughing and breathing. - they have different protein spikes that affect different cells in the respiratory tract of humans.

Antibiotic resistance can happen when...

- bacteria produce an enzyme that breaks down antibiotics. - bacteria mutate the gene that codes for the protein that is the target of the antibiotic. - bacteria produce an enzyme that pumps antibiotic out of the cell. - bacteria produce an enzyme that alters antibiotics

Metabolism means: (Choose two).

- building bigger molecules from subunits. - breaking bigger molecules into subunits.

Genes for enzymes that break down or circumvent antibiotics can be passed from one bacteria to another by:

- conjugation (bacterial sex) - transformation (bacterial cells absorbing pieces of naked DNA) - transduction (viruses moving plasmids from one bacteria to another when they infect them)

What are the three serious *consequences of Measles*?

- death - pneumonia - encephalitis

What is significant about this molecule?

- it has a hydrophillic head and a hydrophobic tail.

Plasmids are important because:

- plasmids are easily shared between bacterial cells during bacterial sexual reproduction. - the genes for enzymes that make cells resistant to antibiotics are often on plasmids.

What makes a Staphylococcus aureus cell different from a Staphylococcus epidermidis cell? (Choose more than one).

- the enzyme it produces. - the genes it contains.

The term *"aerobic respiration"* means that a cell: (Choose two)

- uses oxygen as the ultimate electron acceptor. - uses oxygen to make ATP.

Describe how we use bacteria to make human medicines, like Insulin:

-We are now able to place *human DNA* into ____. *Splice genes* for *insulin* production into *plasmids*, allowing the bacteria to *artificially* produce it.

What are the six stages of the *viral infection* process?

1. Attachment 2. Entry 3. Uncoating 4. Hijacking to copy 5. Makes proteins 6. Packages and leaves

What are the three steps of *aerobic respiration*, in very general terms, what happens in each step?

1. Glycolysis (NADH + Glucose = ATP) Prokaryote --> 2. Kreb's cycle (ATP + CO2) 3. Electron transport chain = more ATP and H2O!

Label the tubes with the type of *metabolism* they show:

1. Obligate aerobe 2. Obli anaerobe 3. Micro aerophile 4. Facultative anaerobe 5. Aerotolerant anaerobe

What are the four differences between bacterial cells and human cells that we can *target* with *antibiotics*, to *stop bacterial growth without harming human cells*?

1. bacteria has cell wall(s) 2. smaller eukaryotic cells 3. folic acid- bacteria 4. has different DNA binding proteins

1. What are most of the antibiotics used in the US, used for? 2. Why is that a *problem*?

1. livestock 2. exposure reading to selection. spreading of infection to new sites.

organisms organized in order of INCREASE HEAT TOLERANCE *(tolerates the most heat at the bottom)*

1. psychrophile 2. mesophile 3. thermophile 4. extreme thermophile

What is the difference between a "stand" and "strain"?

A *strand* is connected to DNA ( A, T, C, G ). A *strain* is connected to how viruses change and adapt (flu).

What is *meant* by the term *"obligate anaerobe"*?

An anaerobe will only grow in the absence of free oxygen.

How do most *antifungals* work?

Antifungals *disrupt* the *cell membrane* production, by affecting *enzyme* found in fungi.

The term "facultative" means that a cell:

Can produce ATP with or without oxygen and can do aerobic respiration or fermentation.

How does Ebola (or hemorrhagic viruses) lead to the *death* of a patient?

Causes *organ failure* and interferes with the immune system.

Why do you think it was different (in terms of *ages* of those who died & *what killed them*?

Cytokine storm. The stronger the immune system, the stronger the "storm", the more likely you were to die.

| what enzyme does this possess?

DNA polymerase

What is this process?

DNA replication- when it makes a copy of itself.

The oxygen is electronegative and pulling the electrons down the electron transport chain to the synapse (*cellular respiration*).

Describe what is happening here:

The step which builds a chemiosmotic gradient of protons (H+) is:

Electron Transport Chain

The step which produces the most ATP is:

Electron Transport Chain

Describe how *fermentation* can cause severe disease:

Fermentation can cause *Butyric Acid*, which causes the deterioration of your *skin* and *tissue*.

The first step for both aerobic respiration and fermentation is:

Glycolysis

This image is an example of:

HIV virus infection

How does the improper use of *Tamiflu* lead to Tamiflu-resistant pandemics?

If we *overuse*, we will *select* for *resistant strains* and those will rapidly spread to become *new pandemic*.

What does *specific heat* mean, and why is it important for life on planet Earth?

It absorbs large amounts of energy *without changing temperature* to provide a *stable environment*.

The flu season is during cool or winter months because:

It has a lipid envelope that is stable in cool temperatures, but unstable in hot temperatures.

*H5N1* has higher death rate because...

Lives deeper in the lungs and can cause *cytokine storm*.

A parasite that hangs out in warm fresh water and enters through sinuses to cause encephalitis, with almost 100% death rate, is:

Naegleria fowleri

Why is the *PVL toxin clinically important*?

Patient with *CA*, *MRSA* die much faster. Patient with *HA*, *MRSA* often survive with it.

How does *penicillin* work to *stop bacterial growth*?

Penicillin occupies enzyme active site, meaning the cell wall is not formed and bacteria cannot survive.

Refer to #27: What is the enzyme name? *(RNA --> DNA)*

Reverse transciptase

Describe how soap works:

Soap is a *amphipathic* and can "lift" and "separate" things like dirty grease, viruses and bacteria from the surface of the skin.

What was *Pasteur* trying to prove with these special flasks? Describe how it worked:

That *spontaneous generation* was a *lie*, yet people believed him; The curved neck trapped cells and particles. The broth was not infested with organisms.

What is the difference about the *Spanish flu*?

The *Spanish flu* killed *3% of the world's population*. This specific strada triggered cytokine storms, causing *AROS*to be lethal.

Regarding the question above: What stage *causes* recurring symptoms in the host? & *Why*does it do that?

The *attack phase*; - when it breaks out of RBCs and becomes visible to the immune system.

Why is wintertime the normal flu season?

The *influenza virus* is more stable in the *cold* weather than hot weather.

What *causes* thrush* in *infants*?

The *overgrowth* of *yeast* (fungus) called *Candida*.

Explain what is being done in this diagram, and the *diagnosis* for the patient:

This is called *DNA fingerprinting*- the comparison of different samples in order to identify *unique bonding pattern*to each person's *genomic DNA*.

*Barophile*

Thrives at high atmospheric pressures.

The function of a protein is dependent upon its shape.

True.

Refer to above question: Why or why not?

Viruses are *not* alive and cannot be "killed".

*Translation*

What process is happening here?

How does a patient *stopping* their antibiotic *too early* lead to an *antibiotic resistant infection*?

When taking an antibiotic(s), it kills the *susceptible* bacteria first, the resistant bacteria is what is left. If *antibiotic* is stopped too soon, the *resistant bacteria* stays and *reproduces* - leading to antibiotic *resistant infection*.

What type of organism is it?

a *fungus*

Every virus contains:

a protein coat genetic material as instructions for proteins.

What is *PVL toxin*?

a toxin that inhibits *WBC*

*Most* types of bacterial fermentation will produce __________, which we will be able to detect in lab by pH indicators.

acids

Refer to #27: What is an example of a *waste product that is produced*?

alcohols and lactic acid

A protein is composed of a chain of:

amino acids

*Acidophile*

an organism that grows best at low pH; typically below pH 6. *grows best in acidic environments.*

*Thermophile*

an organism that has adapted to living in very high temperatures (heat), such as bacteria or algae. *grows best in high temperatures.*

Which of the following cell types have cell membranes?

animal bacteria plant fungi

Viruses cannot be destroyed by antibiotics because:

antibiotics target bacterial enzymes and ribosomes

What else is caused by this organism?

appears in diaper rashes and other rashes

Which of these is MOST OFTEN a hyperparasite?

arthopods

Which of the following cell types have peptidoglycan cell walls?

bacteria

How does *Tamiflu* work?

blocking *neuraminidase* (stops virus particles from exiting host cells).

The reason that salt and sugar can be used as preservatives in pickles and jellies is that:

both change the osmotic pressure of a solution, killing many bacteria.

Which type of cells have membranes composed of phospholipids?

both prokaryotes and eukaryotes.

Roundworm infections (like river blindness in humans and heartworm in dogs):

can be prevented with ivermectin treatment.

Bacteria grow by:

cell division

*Vibrio*

comma shaped bacteria

The significance of this molecule is that: a. it stores energy in the phosphate bonds b. it is used by enzymes to fuel metabolic reactions c. it works like a rechargeable battery d. all of the other answers e. it is called ATP

d.

The parasite toxoplasma gondii is most dangerous to which population?

developing fetus in pregnant mothers who get toxoplasmosis.

Identify what is happening here. Why is this important? How does it spread?

diseased prion is becoming it's own enzyme, which encourages misfiring in normal prion protein when it encounters normals.

With bacterial cell division, a mother cell grows large and then:

divides to create two daughter cells.

Why is that important to know when dealing with bacteria?

enzymes are required for *growth* & *division* of bacteria *pH* and *temperature* affect bacterial growth.

Plasmids are:

extra-chromosomal pieces of DNA.

Which of the following is NOT a sterilization procedure?

freezing and pasteurization

Which of the following cell types have *cell walls*?

fungi bacteria plant

We acquire some antibiotics from fungi because:

fungi and bacteria compete for resources and so have chemicals to inhibit each other.

Which of the following also help make up the cell membrane of a eukaryote?

glycoproteins cholesterol glycolipids proteins

*Psychrophile*

grows well in *cold* temperatures.

Fermentation is a way of making small amounts of *ATP and recycling electron carriers*. Describe one way *fermentation benefits humans*:

helps produce *acids* and *breaks down sugars* *food*

What is special about the measles virus?

high rate of complications like blindness and pneumonia. most contagious virus known.

Why is it *important* to *pandemics*?

in the *overuse* of *Tamiflu*, we are selecting for *resistant strains*.

In general terms, explain the life cycle of the *malaria* parasite:

inject parasite, migrates to *liver*, *infects RBC*, breaks out of RBC

What is special about the Ebola virus?

is hemorrhagic and so can lead to organ failure death rate up to 90% depending upon strain

The term "latency" or "dormant" describing a virus means:

it can lie hidden in host cells for long periods of time.

The influenza virus targets respiratory & blood cells because:

it has protein spikes that fit into protein receptors on those cells.

What does this molecule form?

membranes

Is this statement true? "Bacteria have cell walls, but human cells have cell membranes"

no, *false*

What is it meant by *"facultative"*?

organisms that can use oxygen but have anaerobic methods of *energy production* as well. *A bacterium is doing aerobic respiration*

Why are parasite infections often more difficult to cure than bacterial infections?

parasites are eukaryotes, while bacteria are prokaryotes, so medications cause side effects.

Which type of antibiotic interferes with the construction of peptidoglycan?

penicillin

This image is an example of:

prion infection

difference between prokaryotes and eukaryotes is:

prokaryotes have plasmids

Which of the following describes *epigenetics*:

protein expression is altered by how tightly the DNA is wound

The process by which viruses can exchange genes within a single host, and therefore create new strains (antigenic shift) is known by two terms:

reassortment recombination

*Microaerophile*

requires a small amount of oxygen but won't grow at normal atmospheric levels. *grows well in low oxygen environments.*

This picture is an example of:

rhinovirus infection

Prokaryotic cells have:

ribosomes DNA mRNA

Eukaryotic cells have: (Select all the correct answers, and you can figure out how many are correct).

ribosomes DNA mRNA membrane-bound organelles a nucleus

*Bacilli*

rods

Sketch how Penicillin works to stop bacterial growth:

rupture : where the enzyme normally stitches together to peptidogylcan to form a cell wall.

*Halophile*

salt-loving.

*Coccus*

spherical bacteria

*Spirillum*

spiral shaped bacteria

*Spirochete*

spiral shaped bacteria

What does an *autoclave* do?

sterilizes equipment

Which part of the virus is usually the part recognized by the immune system?

surface antigens

The point of sporulation is:

surviving nutrient poor or extreme environmental conditions.

The organelle that does the matching of transfer RNAs with amino acids with the right codon on mRNA is called:

the *ribosome*

When we say a cell is aerobic or fermentative, we are indicating:

the method it uses to make APT.

Malaria causes repeated cycles of fever and chills, and then symptoms disappear, because:

the parasite breaks out of blood cells to be visible to the immune system, then reinfects blood cells to disappear.

The reason bacteria have an "optimum growth range" and a "tolerant range" in temperature and pH is because:

they have enzymes that work best in those ranges, and denature outside of their tolerant range.

Viruses are called intracellular parasites because:

they must use host cellular enzymes to make new DNA and proteins

*Capnophile*

thrives in high carbon dioxide environments.

How does a virus like HPV cause cancer?

viral proteins shut down "guardian" proteins that stop cell from replicating if cancer-causing mutations occur.

Which stage of the malaria parasite life cycle causes cyclical fevers in the host?

when it breaks out of RBC and becomes visible to the immune system.

In what *timeframe* must *Tamiflu* must be given?

within *48 hours* of start of symptoms.

How do you *prepare medical equipment* for autoclaving?

wrap instruments for steam processing, add initials, insert indicator strip, and open.