Chapter 40

Question 1

Acquired immunodeficiency syndrome (AIDS)

Answer 1

Infection caused by the human immunodeficiency virus (HIV), which weakens the host’s immune system, giving rise to opportunistic infections

Question 2

Antibodies

Answer 2

Immunoglobin molecules that have an antigen-specific amino acid sequence and are produced by the humoral immune system (antibodies produced from B lymphocytes) in response to exposure to a specific antigen, the purpose of which is to attack and destroy molecules of this antigen

Question 3

Antigen

Answer 3

A substance, usually a protein, that is foreign to a host and causes the formation of an antibody that reacts specifically with that antibody
Examples: bacterial exotoxins, viruses, allergens
An allergen (dust, pollen, mold) is a specific type of antigen that causes allergic reactions

Question 4

Antiretroviral drugs

Answer 4

A specific term for antiviral drugs that work against retroviruses such as HIV

Question 5

Antiviral drugs

Answer 5

A general term for drugs that destroy viruses, either directly or indirectly by suppressing their replication

Question 6

Cell-mediated immunity

Answer 6

One of two major parts of the immune system. It consists of nonspecific immune responses mediated primarily by T lymphocytes (T cells) and other immune system cells (e.g., monocytes, macrophages, neutrophils) but not by antibody-producing cells (B lymphocytes)

Question 7

Deoxyribonucleic acid (DNA)

Answer 7

A nucleic acid composed of nucleotide units that contain molecules of the sugar deoxyribose, phosphate groups, and purine and pyrimidine bases. DNA molecules transmit genetic information and are found primarily in the nuclei of cells

Question 8

Fusion

Answer 8

The process by which viruses attach themselves to, or fuse with, the cell membrane of host cells, in preparation for infecting the cell for purposes of viral replication

Question 9

Genome

Answer 9

The complete set of genetic material of any organism; it may consist of multiple chromosomes (groups of DNA or RNA molecules) in higher organisms; a single chromosome, as in bacteria; or one or two DNA or RNA molecules, as in viruses

Question 10

Herpesviruses

Answer 10

Several different types of viruses belonging to the family Herpesviridae that cause various forms of herpes infection

Question 11

Host

Answer 11

Any organism that is infected with a microorganism, such as bacteria or viruses

Question 12

Human Immunodeficiency Virus (HIV)

Answer 12

The retrovirus that causes AIDS

Question 13

Humoral Immunity

Answer 13

One of two major parts of the immune system. It consists of specific immune responses in the form of antigen-specific antibodies produced from B lymphocytes

Question 14

Immunoglobins

Answer 14

Synonymous with immune globulins. GLycoproteins produced and used by the humoral immune system to attack and kill any substance (antigen) that is foreign to the body. An immunoglobulin with an antigen-specific amino acid sequence is called an antibody and is able to recognize and inactivate molecules of a specific antigen

Question 15

Influenza viruses

Answer 15

The viruses that cause influenza, an acute viral infection of the respiratory tract. There are three types of influenza virus: A, B, and C. Currently, medications are available only to treat types A and B

Question 16

Nucleic Acid

Answer 16

A general term referring to DNA and RNA
These complex biomolecules contain the genetic material of all living organisms, which is passed to future generation during reproduction

Question 17

Nucleoside

Answer 17

A structural component of nucleic acid molecules (DNA or RNA) that consists of a purine or pyrimidine base attached to a sugar molecule

Question 18

Nucleotide

Answer 18

A nucleoside that is attached to a phosphate unit, which makes up the side chain “backbone” of a DNA or an RNA molecule

Question 19

Opportunistic infections

Answer 19

Infections caused by any type of microorganism that occur in an immunocompromised host but normally would not occur in an immunocompetent host

Question 20

Protease

Answer 20

An enzyme that breaks down the amino acid structure of protein molecules by chemically cleaving the peptide bonds that link together the individual amino acids

Question 21

Replication

Answer 21

Any process of duplication or reproduction, such as that involved in the duplication of nucleic acid molecules (DNA or RNA) during the reproduction processes of all living organisms. This is also the term used most often to describe the entire process of viral reproduction, which occurs only inside the cells of an infected organism

Question 22

Retroviruses

Answer 22

Viruses belonging to the family Retroviridae. These viruses contain RNA (as opposed to DNA) as their genome and replicate using the enzyme reverse transcriptase. Currently the most clinically significant retrovirus is HIV

Question 23

Reverse Transcriptase

Answer 23

An RNA-directed DNA polymerase enzyme. It promotes the synthesis of a DNA molecule from an RNA molecule, which is the reverse of the usual process. HIV replicates in this manner

Question 24

Ribonucleic Acid (RNA)

Answer 24

A nucleic acid composed of nucleotide units that contain molecules of the sugar ribose, phosphate groups, and purine and pyrimidine bases. RNA molecules transmit genetic information and are found in both the nuclei and cytoplasm of cells.

Question 25

Virion

Answer 25

A mature virus particle

Question 26

Viruses

Answer 26

The smallest known class of microorganisms; viruses can only replicate inside host cells

Question 27

acyclovir (Zovirax) Mechanism of Action

Answer 27

Work by blocking the activity of a polymerase enzyme that normally stimulates the synthesis of new viral genomes

Question 28

ganciclovir (Cytovene) Mechanism of Action

Answer 28

Work by blocking the activity of a polymerase enzyme that normally stimulates the synthesis of new viral genomes

Question 29

indinavir (Crixivan) Mechanism of Action

Answer 29

Work by inhibiting the protease retroviral enzyme, which promotes the breakup of chains of protein molecules at designated points, which is necessary for viral replication

Question 30

nevirapine (Viramune) Mechanism of Action

Answer 30

Work by blocking activity of the enzyme of reverse transcriptase, which promotes the synthesis of new viral DNA molecules from the RNA genome

Question 31

ziovudine (Retrovir) Mechanism of Action

Answer 31

Work by blocking activity of the enzyme of reverse transcriptase, which promotes the synthesis of new viral DNA molecules from the RNA genome