Week 5

Question 1

What are drugs?

Answer 1

Drugs are substances that cause physiologic effects in the body.

Question 2

What are the steps that a drug goes through a body system? AKA Pharmacokinetics?

Answer 2

1) Absorption (e.g small intestine)
2) Distribution (Drug Allocation)
3) Metabolism (e.g. liver)
4) Excretion (e.g. feces)

Question 3

List the routes of administration of drugs:

Answer 3

Oral, intravenous (IV), intramuscular (IM), intrathecal, rectal, and transdermal routes.

Question 4

What is a drug’s bioavailability?

Answer 4

Bioavailability describes how much of a drug reaches the bloodstream, which can be influenced by the route of administration.

Question 5

True/False: the anti-cancer drug Tamoxifen is one of those drugs that needs to be metabolized in order to be physiologically active.

Answer 5

True

Question 6

If _______ is what the body does to the drug, then _______ is what the drug does to the body.

Answer 6

Pharmacokinetics, Pharmacodynamics

Question 7

What is the difference between drug potency and efficacy?

Answer 7

Potency is a measure of the amount of drug required to reach a desired effect, whereas efficacy is the maximal response achieved by a drug at any dose.

Question 8

The _______ measures differences between minimal effective plasma drug concentrations and minimal toxic plasma drug concentrations.

Answer 8

Therapeutic window

Question 9

The ______ is a ratio of the median dose that produces a toxic effect to the median dose that produces a desired effect.

Answer 9

Therapeutic index TI

Question 10

The resting membrane potential describes the potential difference across a membrane in between ________.

Answer 10

Action potentials

Question 11

Dose required to maintain steady state in continuous infusion of medication: _______

Answer 11

Maintenance dose.

Question 12

Maintenance and loading dose depend on factors: 1) ______ 2) _____ 3)_____

Answer 12

1) Bioavailability
2) Clearance rate
3) Vd (Volume of distribution)

Question 13

All viruses have some sort of genetic code, either DNA or RNA, and a protein coat called a _____.

Answer 13

Capsid

Question 14

How are viruses separated into 3 classes?

Answer 14

1) DNA viruses
2) RNA viruses
3) Retroviruses

Question 15

Name some examples of DNA viruses you may encounter.

Answer 15

dsDNA viruses: Adenovirus, viral conjunctivitis, poxviruses

ssDNA viruses: Parovirus B19

Question 16

True/False: Antisense ssRNA is equivalent to mRNA.

Answer 16

False it is Sense ssRNA that is.

Question 17

Name some example of RNA viruses you may encounter.

Answer 17

Rabies, measles, and Ebola

dsRNA virus: Rotavirus

Question 18

Retroviruses are ___ ssRNA viruses. Most famous of these is ___.

Answer 18

(+) ssRNA (exclusively ssRNA! does not include dsDNA-RT)

HIV

Question 19

Retroviruses have the enzyme ______, which transcribes their RNA into DNA.

Answer 19

Reverse Transcriptase

Question 20

What are the 6 steps of a viral infection of a cell?

Answer 20

1) Attachment
2) Penetration
3) Uncoating
4) Replication: DNA viruses replicate in nucleus, and RNA viruses EXCEPT influenza replicate in cytoplasm.
5) Assembly: New viral nucleic acids, enzymes, and proteins assemble to form new visions.
6) Release

Question 21

A virus will ceaselessly find its way into a cell, how it does that is through targeting _____.

Answer 21

Receptors!

Question 22

HIV will target ______ co-receptors presented on CD4 cells.

Answer 22

CCR5 and CXCR4

Question 23

Cytomegalovirus targets host _______ and ______ located on many host cells.

Answer 23

Glycoproteins and integrins

Question 24

2 mechanisms for virus to get into the cell: 1) ______ and 2) ______

Answer 24

1) Receptor-mediated endocytosis

2) Fusion of the viral envelope with the cell membrane, releasing the capsid into the cell.

Question 25

How would (-) ssRNA viruses replicate?

Answer 25

Most must introduce an enzyme called RNA replicase which forms (+) ssRNA which can function like the RNA of (+) ssRNA.

Question 26

Exceptions of the rule! Poxvirus (dsDNA virus) replicates in the _____, while influenza, a ssRNA virus, replicates in the ____.

Answer 26

Cytoplasm | Nucleus

Question 27

Where do DNA viruses and RNA viruses generally replicate?

Answer 27

DNA viruses replicate in host nucleus RNA viruses replicate in cytoplasm. Generally....

Question 28

Retroviruses not only use the Reverse Transcriptase enzyme to form DNA intermediates, but they also use an enzyme called ______ to integrate DNA intermediates into the host genome.

Answer 28

Integrase

Question 29

Which viruses use host membranes as their envelopes through viral budding?

Answer 29

Influenza and respiratory syncytial virus (RSV)

Question 30

What is the difference between a persistent and a latent infection?

Answer 30

A persistent infection is symptomatic for a prolonged period, such as Hep B. A latent infection is asymptomatic unless reactivated by a trigger.

Question 31

How could a virus benefit from causing inflammation?

Answer 31

If a virus is tropic for white blood cells, inflammation would bring more potential host cells nearby.

Question 32

Which class of DNA virus is NOT double stranded (give an example)?

Answer 32

ssDNA --> Parvoviridae the only clinically relevant ssDNA virus. It's so small, that its clothes don't fit, so it is a "naked" virus.

Question 33

Can viruses have their own RNA Polymerase?

Answer 33

Yes!

Question 34

Most DNA viruses have ____ DNA, though there are some viruses that have _____ DNA.

Answer 34

Linear | Circular

Question 35

Alternatively, naked DNA viruses will ____ the host cell to cause release.

Answer 35

lyse

Question 36

Cytomegalovirus (CMV) presents in patients with such symptoms as pneumonia, ______, and _____.

Answer 36

Esophagitis, and retinitis.

Question 37

What are the three classes of RNA viruses, based on the structure of their genetic material?

Answer 37

dsRNA, (+) ssRNA, and (-) ssRNA

Question 38

Positive sense single stranded RNA viruses contain RNA that can be ______ translated by a host cell.

Answer 38

Directly | Analogous to mRNA

Question 39

How does the RNA of (-) ssRNA viruses differ from that of (+) ssRNA viruses?

Answer 39

Negative-sense single stranded RNA (-) ssRNA have RNA that is complimentary to the translatable mRNA. The (-) ssRNA is a complimentary sequence that needs to be transcribed before it can be used for protein synthesis.

Question 40

So how do (-) ssRNA viruses synthesize proteins if human cells do not contain RNA polymerases that transcribe RNA?

Answer 40

They have their own RNA-dependent RNA polymerase! Once that occurs, host ribosomes are able to translate it into protein used for viral replication.

Question 41

At what step is the viral capsid degraded by viral or host enzymes and the viral genetic material released?

Answer 41

Uncoating

Question 42

Viral RNA polymerases do not have ______ abilities like DNA polymerases, resulting in very high mutation rates.

Answer 42

Proofreding

Question 43

Replicated viral genome and newly synthesized proteins are packaged to create active virus particles called ____. ________ also occurs during assembly.

Answer 43

Virion | Protein modification

Question 44

Where in the host cell do most RNA viruses replicate?

Answer 44

Most RNA viruses replicate in the cytoplasm of the host cell. The exceptions are Orthomyxoviridae and Retroviridae, which replicated in the nucleus.

Question 45

Some (-) ssRNA viruses have segmented RNA, in which their genome is spilt into multiple, smaller pieces. Usually each segment codes for a single protein and can be exchanged between viruses through a process called: ______

Answer 45

Reassortment

Question 46

What two structural characteristics are shared by all (-) ssRNA viruses?

Answer 46

All (-) ssRNA viruses are enveloped and have a helical capsid.

Question 47

All (+) ssRNA viruses have a(n) ______ capsid and ____RNA.

Answer 47

icosahedral and linear RNA

Question 48

Which step of viral replication does maraviroc act on?

Answer 48

Acts on entry/fusion step of replication, and it is one of the drugs considered for antiretroviral therapy.

Question 49

For HIV to enter a host cell, it must bind to a receptor on the surface and then fuse. One of these receptors is CCR5. ____ blocks CCR5, which prevents binding of the virus, causing it to be unable to enter the cell.

Answer 49

Maraviroc (drug)

Question 50

How does HIV bind to the CD4 molecule?

Answer 50

Use of gp-120 to CD4 + co-receptor (CXCR4 and CCR5)

Question 51

________: inhibit reverse transcriptase, chain terminators.

Answer 51

Nucleotide/nucleoside reverse transcriptase inhibitors (NRTIs)

Question 52

________: inhibit reverse transcriptase rendering the elongating DNA strand incomplete and useless. They bind directly to reverse transcriptase, inactivating it. Stop DNA Polymerase from polymerizing.

Answer 52

Non-nucleoside reverse transcriptase inhibitors (NNRTIs)

Question 53

What is the mechanism of action of protease inhibitors?

Answer 53

Viral protease cuts polyprotein chains into functional units, and protease inhibitors stop this final step of viral replication.

Question 54

Why is Type A influenza the most common and severe type?

Answer 54

Able to mutate its H and N glycoproteins during replication.

Question 55

Name the two glycoproteins present on Type A and Type B Flu viruses?

Answer 55

1) Hemagglutinin and 2) Neuraminidase

Question 56

What is the glycoprotein found on Type C flu virus?

Answer 56

Hemagglutinin esterase-Fusion

Question 57

Compare Antigenic Drift vs. Antigenic Shift.

Answer 57

AD: Slight changes in genes leads to slight changes in surface proteins. AS: Major changes, where there is mixture of genes in host leading to Reassortment, which will lead to NEW Hemagglutinin and NEW Neuraminidase.

Question 58

In Influenza viruses, do we need to have RNA Polymerase?

Answer 58

Yes. To change to +ssRNA

Question 59

True/False: Both vaccines TIV and LAIV are trivalent.

Answer 59

True

Question 60

Two types of treatment for Influenza include 1)_____ and 2)_____.

Answer 60

1) Neuraminidase inhibitors; H1N1 commonly resistant | 2) M2 proton channel inhibitor; active against Type A only

Question 61

CTLA-4 will ______ bind to B7 to prevent _____ binding. It actually has more affinity for B7!`

Answer 61

Competitively bind | prevent CD28

Question 62

In B cell activation, B cells CANNOT activate without input from _____.

Answer 62

T cells

Question 63

Cell surface ligand CD45 is helpful in determining various types of T cells. In CD45RA vs. CD45RO, how can you tell which is naive and which is the effector?

Answer 63

CD45RA will have all subunits, not spliced | CD45RO has only their exons! They know what they're looking for, and are ready to attack.

Question 64

During competitive inhibition, we can expect the Km to ____.

Answer 64

be high/increase

Question 65

What happens if there is a mutation in the co-receptor of a CD4 T cell when binding to HIV?

Answer 65

1) If Homozygous, you will have resistance/immunity, since the virus cannot bind to the cell. Get no HIV 2) If Heterozygous, you will just have a slower disease progression, but still get the disease.