Cell Flashcards
Hematoxylin is
a basic dye for acidic structures
Stains nuclei, ribosomes, roughER, DNA, RNA, keratohyalin granules, calcified material blue
Tissue preparation
- Fixate
- Dehydrate
- Clearing - immerse in ethanol
- Infiltrate - place in melted parrafin
- Embedding
- Trimming
Eosin is
an acidic dye for basic strcutres
STains proteins, cytoplasm, collagen, lewy bodies, mallory bodies pink
Periodic acid-Schiff reaction (PAS)
Stains specific cellular compartments and carbohydrates pink
PAS positive: mucins, glycogen, glycocalyx
Nucleu slooks blue or dark-purple
Masson’s trichrome
Used on connective tissue, cartilage, and collagen
Nucleus - black/brown
Keratin, muscle fibers - red
Cytoplasm - pink
Collagen & bone - blue or green
Do ribosomes have a membrane?
No
PS, PE, PI are all phospholipids located where
On the P-face, intracellular
Involved in coagulation, apoptosis, membrane trafficking, signaling
Phosphatidylcholine (PC) and Sphingomyelin (SPH) are where?
on the E-face
Involved in myelin sheath and signaling
Sphingomyelinase
Is on the P-face, but hydrolyzes sphingomyelin on the E-face
Lipid rafts contain high concentrations of
Cholestserol and glycosphingolipids
Importnace of lipid rafts
- Reduces membrane fluidity –> proteins in close proximity interact more efficiently
- Cell-adhesion
- Cell-cell signaling
Transmembrane proteins (receptors, ion channels) and Lipid-anchored proteins (GPI-linked proteins) are ___ proteins.
Integral proteins
Spectrin
Peripheral protein on the P-face that gives RBCs its concave shape by anchoring actin
the spectrin-actin complex is anchored to the cell membrane by ankyrin
What form of endocytosis (phago, pino, receptor-mediated) is clathrin-dependent?
Receptor-mediated endocytosis
What form of endocytosis (phago, pino, receptor-mediated) is actin-dependent?
Phagocytosis
Actin forms a pseudopod that forms a phagosome and engulfs the object –> matures into a lysosome
Juxtacrine signaling
signaling molecule is a cell membrane-bound protein that binds surface receptors of the targe tcell when the two cells make direct physical contact
Niemann-Pick Disease - what is it and what are the symptoms
Deficiency of sphingomyelinase on the P face –> sphingomyelin accumulates on the E face
- Jaundice
- Neurological damage
- Enlarged liver
- Large, fluffy white cells
- Abetaproteinemia –> spiky RBCs (acanthocytes)
Multiple sclerosis (caused by viral infection, treated w interferons) causes an increase in what?
Cytokines that activate sphingomyelinase
–> excessive degradation of myelin sheath (neurodegenerative)
Cystic fibrosis involves a defect in
Cl- channel
–> Cl- can’t leave the cell, so it pulls water in with it, thus engorging the cell to become thick and sticky
Cystinuria
Defective cystine carrier protein in the lumen of the renal proximal tubule –> cystine protein can’t enter the cell, so it leaves through the urine and causes kidney stones
Statins enhance endocytosis of LDL from the blood. Endocytosis of LDL differs from phagocytosis how?
It uses clathrin-coated pits because it’s a receptor mediated endocytosis
Primary cilia
Are on every cell; they are nonmotile; lack dynein; and don’t have a central microtubule pair (9+0 arrangement)
May act as receptors
What do you call the bridges linking microtubule pairs of an axoneme
Nexin
Note: Axoneme = 9+2
The most abundant protein in the cell cortex cross-linked with actin is
filamin
Important for actin’s role in cell-cell junctions
For cilia and flagella to move (microtubules), dynein has to use __
For actin to produce contracitle forces , myosin has to use ___
Both have to use ATP
Aggresomal response
When the cell is damaged, the intermediate filament network collapses and forms masses of damaged proteins to be degraded.
Occurs in liver cells in response to excessive alcohol (forms Mallory’s hyaline) and in Parkinson’s (form’s Lewy bodies)
Kartagener’s syndrome
Defective microtubules can’t mobilize cilia
–> sperm immotility, infertility in women, messed up respiratory system
Colchicine
Prevents tubulin polymerization so that neutrophils can’t migrate to urate crystal deposits during gout
Vinblastine & Vincristine(Oncovin) vs Paclitaxel/Taxol
The V’s inhibit formation of the mitotic spindle so cancer cells and proliferate.
Paclitaxel stabilizes mt’s from depolymerizing to arrest the cancer cell.
Cytochalasin B, and cytochalasin D from fungi
Prevents actin polymerization at the + end –> inhibits lymphocyte migraiton, phagocytosis, and cell division
Phalloidin from poisonous mushrooms
Stabilize actin filaments from depolymerizing –> cell death
Mutations in neurofilaments are common in what disease
Alzheimer’s ; forms neurofibrillary tangles
Mutations in the GFAP gene that give rise to masses of GFAP that interfere with astrocyte mitosis. What disease?
Alexander disease
Leukoencephalopathy, macrocephaly, seizures, psychomotor impairment, death as a child
Mallory bodies: Eosinophilic intracytoplasmic inclusions composed of keratin intermediate filaments
What does a build up of these indicate?
Alcoholic liver cirrhosis
Nuclear import or export requires
GTP hydrolysis
What type of cell death is this?:
Caspase-induced; results in rounded cells; blebs at the cell periphery; cytoplasm stians darker; cell becomes fragmented into bodies phagocytosed by macrophages
apoptosis
What type fo cell deaht is this?
cells get swollen and release their intracellular components into the extracellular space, stimulating macrophages and inflammation; these cells and their remnants are not phagocytosed
Necrosis
Paraptosis
Induced by growth factor receptors (like insulin)
Mediated by MAPK’s
Forms multiple large vacuoles and swollen mitochodnria
Pyroptosis
Induced by infection
Mediated by caspase-1, which activates IL-1 and IL-18 –> inflammation
Start/restriction checkpoint
Occurs right before S
G2/M checkpoint
Ensures that DNA replication is complete
Spindle checkpoint
During metaphase
Ensures that all chromosomes will be segregated
Abnormal complexes of the ETC cause symptoms of:
Muscle weakness, ataxia, seizures, cardiac, and respiratory failure with ragged red fibers on a gomori trichrome stain
What disease is this?
Myoclonic epilepsy with ragged red fibers (an example of mitochondrial cytopathy
What enzyme is deficient in Tay-sachs, resulting in a build up of gangliosides?
Hexosaminidase A
Inability of peroxisomes to incorporate their enzymes because their signaling receptors are missing from the membrane –> Abnormal myelination of nerve cells.
What disease is this?
Zellwegger
Vesicle of a Golgi apparatus that is destined to become part of other organelles is likely to have what on their membrane?
COPII for intracellular anterograde transport
