BIOLOGY 251-GENERAL MICRIBIOLOGY
STUDYGUIDE
BIOL 251 - General Microbiology
FOR
Study Guide EXAM
for Exam 3 3
Chapter 15 – Immunity and Immunization
Know where B cells and T cells mature and the types of cells and functions and the role of the
lymphatic system.
- Dual system of B & T lymphocytes: Immunocompetence
- Specificity – antibodies produced, function only against the antigen that they were
produced in response to
- Memory – lymphocytes are programmed to “recall” their first encounter with an antigen
and respond rapidly to subsequent encounters
B-cells maturation – Memory and Plasma cells and what they do
- Directed by bone marrow sites that harbor stromal cells, which nurture the lymphocyte
stem cells and provide hormonal signals
- Millions of distinct B cells develop and “home” to specific sites in the lymph nodes,
spleen, and GALT
- Come into contact with antigens throughout life
- Have immunoglobulin as surface receptors for antigens
T-cells – T helper cells, Memory and Cytotoxic cells
- Maturation is directed by the thymus gland and its hormones
- Different classes of T-cell receptors termed CD - Cluster of differentiation
- CD4 and CD8
- Mature T cells migrate to lymphoid organs
,Understand what MHC (Major Histocompatibility Complex) receptors are and the role they play
in recognition of self and non-self.
- Receptors found on all cells except RBCs
- Also known as human leukocyte antigen (HLA)
- Plays a role in recognition of self by the immune system and in rejection of foreign tissue
- Genes for MHC clustered in a multigene complex:
- Class I – markers that display unique characteristics of self-molecules and regulation of
immune reactions
- Required for T lymphocytes
- Class II – regulatory receptors found on macrophages, dendritic cells, and B cells
, - Involved in presenting antigen to T-cells
Understand what Antigens are and the types of molecules that make good antigens (Large,
complex molecules are readily recognized and molecules too small or regular in structure are not
recognized as antigens)
- Antigen (Ag) is a substance that provokes an immune response in specific lymphocytes
(T and B cells)
- Property of behaving as an antigen is antigenicity
- Foreignness, size, shape, and accessibility
- Perceived as foreign, not a normal constituent of the body
- Foreign cells and large complex molecules over 10,000 MW are most antigenic
- Antigenic determinant, epitope – small molecular group that is recognized by
lymphocytes
- Antigen has many antigenic determinants
Know what epitopes are and how they influence recognition by antibodies.
- epitope – small molecular group that is recognized by lymphocytes
- Also known as antigenic determinants which provides the primary signal that the
molecule is foreign.
- The shape of this determinant fits like a key to the receptor “lock” of the lymphocyte,
which then responds to it.
Know what antibodies are and the molecular shape of Immunoglobulins (Ig): Heavy and light
chains and the constant and variable section on Ig and their role in recognition of antigens.
- Immunoglobulins are large glycoproteins that serve as specific receptors of B cells
- Composed of 4 polypeptide chains:
- 2 identical heavy chains (H):
- For a heavy chain, a variable region gene segment and diversity region gene segment
are selected from among the hundreds available and spliced to one joining region gene
and one constant region gene.
- 2 identical light chains (L):
STUDYGUIDE
BIOL 251 - General Microbiology
FOR
Study Guide EXAM
for Exam 3 3
Chapter 15 – Immunity and Immunization
Know where B cells and T cells mature and the types of cells and functions and the role of the
lymphatic system.
- Dual system of B & T lymphocytes: Immunocompetence
- Specificity – antibodies produced, function only against the antigen that they were
produced in response to
- Memory – lymphocytes are programmed to “recall” their first encounter with an antigen
and respond rapidly to subsequent encounters
B-cells maturation – Memory and Plasma cells and what they do
- Directed by bone marrow sites that harbor stromal cells, which nurture the lymphocyte
stem cells and provide hormonal signals
- Millions of distinct B cells develop and “home” to specific sites in the lymph nodes,
spleen, and GALT
- Come into contact with antigens throughout life
- Have immunoglobulin as surface receptors for antigens
T-cells – T helper cells, Memory and Cytotoxic cells
- Maturation is directed by the thymus gland and its hormones
- Different classes of T-cell receptors termed CD - Cluster of differentiation
- CD4 and CD8
- Mature T cells migrate to lymphoid organs
,Understand what MHC (Major Histocompatibility Complex) receptors are and the role they play
in recognition of self and non-self.
- Receptors found on all cells except RBCs
- Also known as human leukocyte antigen (HLA)
- Plays a role in recognition of self by the immune system and in rejection of foreign tissue
- Genes for MHC clustered in a multigene complex:
- Class I – markers that display unique characteristics of self-molecules and regulation of
immune reactions
- Required for T lymphocytes
- Class II – regulatory receptors found on macrophages, dendritic cells, and B cells
, - Involved in presenting antigen to T-cells
Understand what Antigens are and the types of molecules that make good antigens (Large,
complex molecules are readily recognized and molecules too small or regular in structure are not
recognized as antigens)
- Antigen (Ag) is a substance that provokes an immune response in specific lymphocytes
(T and B cells)
- Property of behaving as an antigen is antigenicity
- Foreignness, size, shape, and accessibility
- Perceived as foreign, not a normal constituent of the body
- Foreign cells and large complex molecules over 10,000 MW are most antigenic
- Antigenic determinant, epitope – small molecular group that is recognized by
lymphocytes
- Antigen has many antigenic determinants
Know what epitopes are and how they influence recognition by antibodies.
- epitope – small molecular group that is recognized by lymphocytes
- Also known as antigenic determinants which provides the primary signal that the
molecule is foreign.
- The shape of this determinant fits like a key to the receptor “lock” of the lymphocyte,
which then responds to it.
Know what antibodies are and the molecular shape of Immunoglobulins (Ig): Heavy and light
chains and the constant and variable section on Ig and their role in recognition of antigens.
- Immunoglobulins are large glycoproteins that serve as specific receptors of B cells
- Composed of 4 polypeptide chains:
- 2 identical heavy chains (H):
- For a heavy chain, a variable region gene segment and diversity region gene segment
are selected from among the hundreds available and spliced to one joining region gene
and one constant region gene.
- 2 identical light chains (L):
