ESSENTIAL CELL BIOLOGY CHAPTER
#20 EXAM QUESTIONS AND ANSWERS
Proteoglycans - ANSWER-ECM proteins with complex of negatively-charged
polysaccharides; the glycosaminoglycans (GAGs)
GAGs - ANSWER-Attract water, form gels that resist compression
Heparin-sulfate Proteoglycans - ANSWER-- attached to cell surface
- core protein spans membrane and attaches to actin cytoskeleton
Epithelial Cells - ANSWER-- form polarized sheets, resting on basal lamina
- packed together in different ways to form epithelial sheet
Basal Lamina - ANSWER-- provides cell support
- maintains cell polarity
- separates adjacent tissue
- substrate for cell migration
- barrier to passage of macromolecules
- filtration in kidney
Basement Membrane - ANSWER-Basal lamina and reticular lamina
Tight Junction - ANSWER-Seals neighbouring cells together in an epithelial sheet to
prevent leakage of molecules between them
Adherens Junction - ANSWER-Joins an actin bundle in one cell to a similar bundle in a
neighbouring cell, often form an "adhesion belt"
Desmosome - ANSWER-Joins the intermediate filaments in one cell to those in a
neighbour:
- link keratin and other IF to one another
- confer great tensile strength
Gap Junction - ANSWER-Allows the passage of small water-soluble ions and molecules
in the cytosol
Hemidesmosome - ANSWER-Anchors intermediate filaments in a cell to the basal
lamina
- broken when skin is blistered
Blood Brain Barrier - ANSWER-- brain capillaries are wrapped with layers of epithelial
cells with tight junctions
- restrict chemicals and ions that are water soluble
, - caffeine and EtOH are lipid soluble and pass through
Cadherins Junction - ANSWER-- linker proteins connect cadherins to actin
- E, N, and P cadherins
Bullous Pemphigoid - ANSWER-- autoimmune disorder
- body makes antibodies directed against protein found in hemidesmosomes
- dermis separates from the epidermis forming blisters (bullae)
Tissues - ANSWER-Intricate mixtures of cell types that have preserved structures
Cell Communication - ANSWER-New cells are produced only when needed, in
response to signals from other cells - e.g. mitogens
Selective Cell-Cell Adhesion - ANSWER-Different cells have different cadherins and
other adhesion molecules that stick selectively to other cells of the same type of specific
ECM components
Cell Memory - ANSWER-Patterns of gene expression start during embryonic
development and are maintained and passed onto progeny cells
Epigenetic Alterations - ANSWER-Changes that don't alter DNA sequence
Differentiation - ANSWER-Results in cells that do not divide
Stem Cells - ANSWER-Cells that can self-renew, replace themselves, and differentiate
into many cell types
Intestinal Epithelial Lining - ANSWER-Continuously renewed
Epidermis - ANSWER-Continuously renewed by stem cells in basal lamina
Blood Cells - ANSWER-Continuously renewed from haematopoietic stem cells
Haematopoietic Stem Cells - ANSWER-Cells located in the bone marrow that self-
renew and differentiate to form all blood cell types
Wnt Signaling Pathway - ANSWER-Maintains cell proliferation in the intestinal crypt
Therapeutic Stem Cell Use - ANSWER-1. Study of cell division and differentiation
2. Disease models and drug development
3. Cell-based therapies
Cell-Based Therapies - ANSWER-- replace dopamine producing cells in brains of
Parkinson's patients
- develop insulin producing cells to treat Type I diabetes
#20 EXAM QUESTIONS AND ANSWERS
Proteoglycans - ANSWER-ECM proteins with complex of negatively-charged
polysaccharides; the glycosaminoglycans (GAGs)
GAGs - ANSWER-Attract water, form gels that resist compression
Heparin-sulfate Proteoglycans - ANSWER-- attached to cell surface
- core protein spans membrane and attaches to actin cytoskeleton
Epithelial Cells - ANSWER-- form polarized sheets, resting on basal lamina
- packed together in different ways to form epithelial sheet
Basal Lamina - ANSWER-- provides cell support
- maintains cell polarity
- separates adjacent tissue
- substrate for cell migration
- barrier to passage of macromolecules
- filtration in kidney
Basement Membrane - ANSWER-Basal lamina and reticular lamina
Tight Junction - ANSWER-Seals neighbouring cells together in an epithelial sheet to
prevent leakage of molecules between them
Adherens Junction - ANSWER-Joins an actin bundle in one cell to a similar bundle in a
neighbouring cell, often form an "adhesion belt"
Desmosome - ANSWER-Joins the intermediate filaments in one cell to those in a
neighbour:
- link keratin and other IF to one another
- confer great tensile strength
Gap Junction - ANSWER-Allows the passage of small water-soluble ions and molecules
in the cytosol
Hemidesmosome - ANSWER-Anchors intermediate filaments in a cell to the basal
lamina
- broken when skin is blistered
Blood Brain Barrier - ANSWER-- brain capillaries are wrapped with layers of epithelial
cells with tight junctions
- restrict chemicals and ions that are water soluble
, - caffeine and EtOH are lipid soluble and pass through
Cadherins Junction - ANSWER-- linker proteins connect cadherins to actin
- E, N, and P cadherins
Bullous Pemphigoid - ANSWER-- autoimmune disorder
- body makes antibodies directed against protein found in hemidesmosomes
- dermis separates from the epidermis forming blisters (bullae)
Tissues - ANSWER-Intricate mixtures of cell types that have preserved structures
Cell Communication - ANSWER-New cells are produced only when needed, in
response to signals from other cells - e.g. mitogens
Selective Cell-Cell Adhesion - ANSWER-Different cells have different cadherins and
other adhesion molecules that stick selectively to other cells of the same type of specific
ECM components
Cell Memory - ANSWER-Patterns of gene expression start during embryonic
development and are maintained and passed onto progeny cells
Epigenetic Alterations - ANSWER-Changes that don't alter DNA sequence
Differentiation - ANSWER-Results in cells that do not divide
Stem Cells - ANSWER-Cells that can self-renew, replace themselves, and differentiate
into many cell types
Intestinal Epithelial Lining - ANSWER-Continuously renewed
Epidermis - ANSWER-Continuously renewed by stem cells in basal lamina
Blood Cells - ANSWER-Continuously renewed from haematopoietic stem cells
Haematopoietic Stem Cells - ANSWER-Cells located in the bone marrow that self-
renew and differentiate to form all blood cell types
Wnt Signaling Pathway - ANSWER-Maintains cell proliferation in the intestinal crypt
Therapeutic Stem Cell Use - ANSWER-1. Study of cell division and differentiation
2. Disease models and drug development
3. Cell-based therapies
Cell-Based Therapies - ANSWER-- replace dopamine producing cells in brains of
Parkinson's patients
- develop insulin producing cells to treat Type I diabetes
