Acute infection- shows their symptoms immediately and dissipates quickly.
Amino acid- organic nitrogenous compounds that act as the structure of proteins and are synthesized or obtained by cells as a regular diet.
Antibody- proteins created in blood and tissue by the immune system to help neutralize and destroy possible threats.
Antigen- a toxin or enzyme which stimulates reactions from a body's immune system.
Antigenicity- The ability of an antigen to combine with antibodies and T-cell receptors to invoke a reaction from the immune system.
Autoimmune diseases– diseases caused when the immune system turns on itself because it fails to recognize its own cells.
B lymphocyte cells- bursa-dependent; manufactured in the bone; identify antigens and produce antibodies.
Bacteriophages- viruses that infect and kill harmful bacteria.
Base pair- a twin pair of nucleotides contained in a nucleic acid strand, which are linked together by hydrogen bonds.
Body fluids- fluids of the body, including circulating blood and lymph, the chyle, the gastric, pancreatic, and intestinal juices, the saliva, bile, urine, aqueous humor, and muscle serum
Budding- mature viruses leave a cell slowly, a few at a time, not killing the host cell in the process.
Bursa- a tissue space lined by joint tissue; bursas are found in between tendon and bone, skin and bone and muscles.
Carrier- one who carries a virus either in form of an infection or while it is in incubation.
Capsid- The protein outer covering of a virus made up of capsomeres; stimulates the body's immune response.
Cell- a small, enclosed unit containing the DNA, proteins, and chemicals needed for all life functions.
Chromosomes- a DNA containing body that holds most or all of the genes of an individual life form.
Chronic infection- recurring viral infections that cause damage of cells over a long period of time by disrupting their functions.
CNS- the central nervous system, which is comprised of nerves, the brain and the spinal cord.
Connective tissue- tissue that surrounds other more highly ordered tissues and organs; blood, cartilage and bone.
Cytoskeleton- protein filaments that extend through the cytoplasm of cells and enable them to move and change shape.
DNA- deoxyribonucleic acid, the basic component of all living matter, which is contained in the chromosomes of a cell's nucleus; transmits hereditary information and contains gene sequences.
Differentiated- a type of cell, which specializes in one specific task or has one specific purpose.
Dormant- being in a state of suspended animation, not actively growing but protected from the environment.
Electron Microscopy- an imaging method, which uses a focused beam of electrons to enlarge the image of an object on a screen or photographic plate.
Endocytosis- the process in which cells take in fluids or other large molecules.
Enzyme- a type of protein, which catalyzes the reactions between substrates (substances).
Filovirus- The thread-like virus family which includes such viruses as Ebola and Marburg; very deadly.
Genes- a sequence of DNA or RNA that is located on a chromosome and that is the functional unit of inheritance controlling the transmission of traits and function of other genetic material.
Glycoprotein- a compound produced by mixing a protein with any member of a carbohydrate group.
Helper T cells- coordinate the actual immune response of the body; they let other T cells and B cells do their jobs.
Hemorrhagic fever- a condition characterized by non-stop internal or external bleeding resulting from a viral infection which has caused blood vessel damage.
Hereditary material - material responsible for the transmission of qualities from ancestor to descendant through genes.
Host- a living organism, which provides subsistence or lodgment to a parasite.
Humoral immune response- the immune responses mediated by antibodies.
Inactivated vaccine- dead microorganisms used as antigens to produce immunity.
Inclusion bodies- strange and unusual structures found inside a host cell during virus replication.
Infection- the state produced by the presence of an infective agent in or on a suitable host.
Immune System- A body function designed to defend the body from disease causing microorganisms.
Immunity- the condition of being immune, the protection against infectious disease.
Latent infection- viral infection in which the virus responsible is able to avoid the hosts immune system and defenses.
Leukocytes- the majority of the specialized cells used in the immune system; white blood cells.
Lipid- a fatty and oily compound used by cells as energy reserves and material for structure.
Lymph nodes- small bean-shaped organ made up large numbers of lymphocytes, macrophages and accessory cells located along the lymphatic system
Lymphoid tissue- tissue made up white blood cells and special fibers.
Lysis- the cell membrane of a host is completely destroyed and newly replicated viruses are unleashed instantaneously.
Macrophage- contains lysosomes full of special enzymes and chemicals, which allows it to ingest and digest dangerous microbes
Memory cells- keep the body prepared for the next struggle with antigens that have already been encountered.
mRNA (messenger RNA)- used as the carrier of genetic codes and information directly from DNA to cell structures.
Mutation- a rearrangement of genes or change in base pairs so they produce different effects within their environment.
Nanometer- One-millionth of a millimeter.
Nucleic acid- an organic compound made up of a phosphoric acid, a carbohydrate and a base of purine or pyrimidine; formed in helical chains.
Nucleus- a cellular organelle that is the essential control mechanism for cell function; contains the DNA and genetic material.
Origin- location where the process of replication in a nucleic acid begins.
Parasite- an organism living in or on another organism that depends on its host for existence or support and gives nothing in return.
Pathogenesis- the growth and development of a disease.
Prion- an infectious crystallizing protein, which affects the brain.
Proteins- strands of amino acids which make the enzymes and structures needed for cells to grow and function properly.
RNA (ribonucleic acid)- strings of organic material, obtained from DNA, which store the proper instructions necessary to produce amino acids.
Receptor- a structure on a cell which joins with proteins to produce changes in cellular function.
Replication- the action or process of reproducing exact copies of one's self.
Retrovirus- An RNA virus that converts its RNA into DNA by means of the enzyme reverse transcriptase and integrates itself directly into the host's DNA.
Reverse transciptase- special enzyme which allows retroviruses to translate genetic code from RNA to DNA.
Ribosome- the spherical structure that assembles proteins after being fed the genetic instructions by mRNA.
Spleen- an organ that produces lymphocytes, filters the blood, and stores blood cells
Strain- a specific type, quality, or disposition of a material.
Suppressor T cells- monitor and adjust antibody levels in the body; act as suppressors to counteract the Helper and Killer T cells at the end of infections.
Thymus- The lymphoid organ in which T lymphocytes are educated, mature and multiply.
T lymphocyte cells- thymus dependent cells, coordinate the cell-mediated immune system.
Transcription- constructing a mRNA molecule using a DNA molecule as a template; results in the transfer of genetic information to the mRNA.
Vaccine- Weakened or destroyed microorganisms used to help provide immunity to a certain disease or microorganism and to stimulate the production of antibodies.
Variant- a variation of a particular strain of virus or infective agent; slightly different in form or function.
Vector- anything capable of moving or transferring genetic material.
Viroid- exotic type of virus which only infects plant cells and is simply a group of naked strings of amino acids with no covering.
Virus- infectious organism that replicates itself in the cells of a host; viruses have a half alive/half dead existence and need a host to grow and reproduce.