Part 1 Flashcards
calcium-dependent cell adhesion molecules
cadherins and selectins
calcium-independent cell adhesion molecules
integrins, immunoglobulin superfamily
homophilic adhesions, stabilized by actin cytoskeleton (bound to actin via catenins)
cadherins
cell adhesion molecule; binds to carbohydrates; found on endothelial and blood cells
selectins
heterodimer, binding site inside cell binds cytoskeletonal actin via alpha-actinin; outside cell binds other ligands
integrins
HIV-1 receptor (CD4) on lymphocyte) is a member of this type of cell adhesion molecule
immunoglobulin superfamily
In occluding junctions, the transmembrane protein ____ interacts with the integral membrane protein ____.
occludin; claudin
Belt-like cell junction; interaction of cadherins with catenins; interacts with actin cytoskeleton
zona adherens
spot-like junction stabilized by intermediate filaments; involve cadherins
desmosomes
anchor basal portion of cell to basal lamina; linked to intermediate filaments
hemidesmosome
communicating junction; six connexins associate to form a connexon
gap junctions
microtubule arrangement of cilia and flagella
9+2 (basal body s 9+3)
cilia develop from ___ which are derived from ___
basal bodies; centrioles
Autosomal recessive Glanzmann thrombasthenia; Epidermolysis bullosa
integrin defects
4 components of nucleus
nuclear envelope
nucleoplasm
chromatin
nucleolus
heterochromatin vs. euchromatin
heterochromatin is transcriptionally inactive; euchromatin is active.
4 key features of nuclear import-export
requires energy (GTP) requires recognition sequence on a protein importin/exportin: move things across nuclear pore nuclear pore changes in size during transport
fundamental packing unit of chromatin
nucleosome
basophilic stain
Hematoxylin
acidophilic stain
Eosin
stains reticular fibers (Type III collagen)
Silver stain
stains glycogen and various carbohydrate-containing molecules
PAS (periodic acid Shiff stain)
Microtubules are composed of ____.
Microfilaments are composed of ___.
Intermediate fillaments… ____.
tubulin
actin
keratins, lamins, or vimentin?
in microtubules, ___ move organelles toward the + end and ___ move them toward the - end.
kinesins
dyneins
In microtubules, ____ determines growth and stability
GTP/GDP ratio
Taxol, Vinca alkaloids, nocodazole, vinblastine vincristine, and colchicine
interfere with microtubule function
Microfilaments require ___
ATP
Intermediate filament: Type I and II
cytokeratins
acidic and basic keratins (respectively)
at least 1 of each type found in all epithelial cells
Intermediate filament: Type III
Vimentin: mesenchymal, endothelial and leukocytes (generic type III, characteristic of dedifferentiation of invasive cancer carcinomas)
Desmin: skeletal muscle in Z disc; smooth muscle
Intermediate filament: Type IV
neurofilaments: axons and dendrites.
** unique structure: square basket-like lattice
Endoplasmic reticulum is ___ in H&E
basophilic
5 major Golgi functions
- modify N-oligosaccharides on asparagine
- Distribute non-cytosolic proteins to plasma membrane, lysosomes, and secretory vesicles
- assemble proteoglycans from proteoglycan core proteins
- add mannose-6-phosphate to proteins targeted for lysosomes
- sulfates sugars on proteoglycans
Key functions of peroxisomes
beta oxidation of long chain fatty acids
detox of substances
bile acid synthesis in the liver
Zellweger Syndrome: defect, no peroxisomes, lethal
protein; part of coated vesicle; mediates transport of vesicles from trans-golgi network and from the plasma membrane
clathrin
caveolin is similar; for small vesicles called caveolae involved in pinocytosis. clathrin-independent endocytosis.
cell specialized for phagocytosis
macrophage (degrade proteins/cellular debris)
example of constitutive exocytosis
albumin (from liver)
Tay-Sachs, Hurler’s syndrome, Gauchers syndrome, and Neiman-Pick disease are examples of _______.
Lysosomal storage diseases
Myelination in CNS:
Myelination in PNS:
oligodendrocytes
Schwann cells
Plasma membrane of axon:
Cytoplasm of axon:
axolemma
axoplasm
Transport of metabolites in axon from cell body to nerve ending is _____; transport occurs with ____.
(opposite is…)
orthograde; kinesin
retrograde; cytoplasm ic dynein
CNS white matter; long, slender, minimal branching astrocyte
Fibrous astrocytes
compare to protoplasmic astrocytes: granular cytoplasm, processes short and grnached, CNS gray matter
protein critical to apoptosis (proteolytic enz)
caspase
mucus gland secretions are ___ in H&E and ___ in PAS
translucent; dark magenta
responsible for preservation of lipids in SEM/TEM
osmium tetroxide
“sugar coat” associated with extracytoplasmic aspect of the outer leaflet of the plasma membrane; fuzzy in TEM; contains proteoglycans
glycocalyx / ‘sugar coat’
in freeze-fracture, integral proteins preferentially remain attached to ____
P-face: protoplasmic external surface of inner leaflet (rather than internal E-face)
stereospecific transporter of D-glucose; multipass transmembrane protein
GLUT1
proteins for cell cycle regulation (2)
complex that initiates S phase
complex that initiates mitosis
cyclins
cyclin-dependent kinases (Cdk)
start kinase
M-phase promoting factor
division of the nucleus
karyokinesis
two types of microtubules: one radiates from centrosomes and positions spindle poles; the other extends from poles to overlap in the middle (push poles apart)
astral microtubules
polar microtubules
when nuclear envelope reforms, microtubules disappear, and nucleoli reappear
telokinesis
key feature of apoptotic cells
chromatin condenses and marginates; membrane blebs
regulate mitochondria membrane potential; can be pro- or anti-apoptotic. Can activate mitochondrial-mediated apoptosis (membrane potential collapses, proteins released…)
Bcl-2 family of proteins
possible fates of receptor and ligand in endocytosis (3)
- ligand degraded in lysosome; receptor recycled (LDL)
- ligand and receptor recycled (transferrin)
- ligand and receptor both degraded in lysosome (epidermal growth factor)
nucleus component only visible in interphase by ___ staining
nucleolus, basophilic (because rRNA)
