Quiz 4 Flashcards
Immunity
The ability of a host to resist infection or disease (made up of innate and adaptive immunity)
Innate Immunity
Occurs rapidly and acts as a first line of defense
* Non-specific, provides basic mechanisms of defense (ex. physical barriers (skin), complement system, cytokines, and macrophages)
Adaptive Immunity
Acquired by the host in response to the presence of a foreign substance (antigen)
____ formation is stimulated by the presence of an antigen
Antibody (protein produced by B cells, inactivates or destroys antigen responsible for activation)
Immunoglobulins
Antibodies residing in the host serum (plasma)
____ are the major cells of the adaptive immune system
Lymphocytes (2 major types: B cells and T cells)
B Cells
Produced and mature in bone marrow, differentiation into AB or Ig secreting plasma cells and memory cells upon activation
Opsonization
When antibodies coat bacteria and parasites to make them more readily recognized to be engulfed by phagocytic cells
T Cells
Originate in bone marrow, mature in the thymus gland before circulating in the blood or residing in lymphoid organs (i.e. lymph nodes and spleen), divided into helper T cells and cytotoxic T cells
Helper T Cells
Required to hellp B cells respond to most extracellular antigens, produce cytokines that affect B cell differentiation and the activation of other cells (macrophages)
Cytotoxic T Cells
Can directly kill cells that have been infected with an organism (e.g., a virus or intracellular bacterium)
Major Histocompatibility Complex (MHC)
Utilized by all nucleated (Class I - intracellular) cells and cells within the innate immune response PAPCs (Class II - extracellular) to activate cytotoxic T cells and helper T cells respectively
T Cell Receptors (TCRs)
On surface of T cells, interact with antigenic peptide and the MHC molecule presenting it
Cluster of Differentiation (CD) Molecules
Function as receptors and co-receptors, play an important role in intercellular communication (ex. CD4 is used by helper T cells, while CD8 is used by cytotoxic t cells)
Enzyme-Linked Immunosorbent Assay (ELISA)
A common method to test for the presence of Abs in serum (used as an initial screen for HIV by assaying for Abs to the envolpe glycoprotein gp120 in human serum)
Smaller, cleaved “antigen” fragments will be ____ to identify with Abs
harder
Biofilms can be constructed by ____ or ____ species on nearly any surface
single, numerous collaborating
3 Distinct Biofilm Stages
- Attachment
- Colonization
- Maturation/Dispersal
Attachment is carried out by motile ____ cells
planktonic
Factors that influence biofilm formation include:
- Optimal growth conditions
- Nutrient efficiency
- Shape
Defined Medium
A medium in which the components are known (useful when studying the metabolism of an organism)
Complex Medium
Contains some ingredients of unknown composition (useful if a sufficiently rich and complete medium is needed for many microorganisms, or if the nutritional requirements of a microbe is unknown)
General Purpose Medium
Allows the growth of many microorganisms
Enrichment Medium
Selects the microorganism of highest growth rate among the microbes able to grow under the set conditions
