ExamReview2 (1).docx - Questions Describe the structure of...

Questions
Describe the structure of a focal adhesion, Adherins Junction,
hemidesmosome and desmosome.
● Adherens Junction-
● Focal Adhesions and hemidesmosomes are created from integrins
● Focal Adhesion - cell to matrix junction linking extracellular proteins to actin
filaments, composed of integrins
● Hemidesmosomes- i t is a cell to matrix linkage that is composed of integrins
that links extracellular matrix proteins to intermediate filaments
Pick any tissue you want and describe the following:
● 3 cell types found
● how each cell contributes to the function
● cell- cell junctions or cell to matrix?
● which cell type is the major contributer
Epithelial tissues /skin contain fibroblasts, immune cells, and endothelial tissues.
Fibroblast makes ECM. Immune cells help to protect these cells from infection and
endothelial cells bring proteins oxygen and other essential molecules needed for
function. Because epithelial tissues are a barrier to foreign bodies, it would be
composed mostly of cell to cell junctions to prevent pathogens from entering.
Basal Membranes- Basal membranes that are not intact tend to have higher rates of
metastasis. Basal membranes act as a barrier taht protects harmful cells from
spreading into the bloodstream. Proteasess that degrade the basal membrane can
lead to metastasi s
Explain the difference b/w necrosis and apoptosis.
Necrosis Apoptosis
● cell death due to mechanical
stress/ rupture
● abnormal and harmful to cells,
organelles may not be intact/
cannot be recycled
● random, proteins and
eveything is expelled into the
extracelular space
● programmed cell death
● can be healthy, organellese
remain intact and can be
recycled
● involves caspases
● compartmentalized controlled
cell death

Activation of integrins slows down the cell during movement. explain why.
● Cells use integrins to move by turning them on and off.
● Cell movement is caused by integrins on the front of the cell turning on and
integrins on the back of the cell being turned off to release the cell and allow
the cell to crawl
● integrins that remain adhered would offer resistance to cell movement and
thus slow it down
Identify which cytoskeletonal proteins are denoted. Which is the weakest?
Whichj proteins resist compression and which resist tension?
● Intermeidate filaments- are the strongest and the most flexible, resist
tension
● Microtubules- are much more rigid and fail britally; they resist
compressive forces and are the weakest because they can withstand the
least stress
● Actin- not as weak and resist tensile loads
How do kinesin, dyamin, and myosin contribute to mitosis?
Kinesin Dyamin Myosin
● Help the cell
grow
● dyamin helps
transport
materials away
from the MTOC to
the + end;
● thus seperating
the chromosomes
●