Cell

Question 1

Hematoxylin is

Answer 1

a basic dye for acidic structures

Stains nuclei, ribosomes, roughER, DNA, RNA, keratohyalin granules, calcified material blue

Question 2

Tissue preparation

Answer 2

• Fixate
• Dehydrate
• Clearing - immerse in ethanol
• Infiltrate - place in melted parrafin
• Embedding
• Trimming

Question 3

Eosin is

Answer 3

an acidic dye for basic strcutres

STains proteins, cytoplasm, collagen, lewy bodies, mallory bodies pink

Question 4

Periodic acid-Schiff reaction (PAS)

Answer 4

Stains specific cellular compartments and carbohydrates pink

PAS positive: mucins, glycogen, glycocalyx

Nucleu slooks blue or dark-purple

Question 5

Masson’s trichrome

Answer 5

Used on connective tissue, cartilage, and collagen

Nucleus - black/brown

Keratin, muscle fibers - red

Cytoplasm - pink

Collagen & bone - blue or green

Question 6

Do ribosomes have a membrane?

Answer 6

No

Question 7

PS, PE, PI are all phospholipids located where

Answer 7

On the P-face, intracellular

Involved in coagulation, apoptosis, membrane trafficking, signaling

Question 8

Phosphatidylcholine (PC) and Sphingomyelin (SPH) are where?

Answer 8

on the E-face

Involved in myelin sheath and signaling

Question 9

Sphingomyelinase

Answer 9

Is on the P-face, but hydrolyzes sphingomyelin on the E-face

Question 10

Lipid rafts contain high concentrations of

Answer 10

Cholestserol and glycosphingolipids

Question 11

Importnace of lipid rafts

Answer 11

• Reduces membrane fluidity –> proteins in close proximity interact more efficiently
• Cell-adhesion
• Cell-cell signaling

Question 12

Transmembrane proteins (receptors, ion channels) and Lipid-anchored proteins (GPI-linked proteins) are ___ proteins.

Answer 12

Integral proteins

Question 13

Spectrin

Answer 13

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

Question 14

What form of endocytosis (phago, pino, receptor-mediated) is clathrin-dependent?

Answer 14

Receptor-mediated endocytosis

Question 15

What form of endocytosis (phago, pino, receptor-mediated) is actin-dependent?

Answer 15

Phagocytosis

Actin forms a pseudopod that forms a phagosome and engulfs the object –> matures into a lysosome

Question 16

Juxtacrine signaling

Answer 16

signaling molecule is a cell membrane-bound protein that binds surface receptors of the targe tcell when the two cells make direct physical contact

Question 17

Niemann-Pick Disease - what is it and what are the symptoms

Answer 17

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)

Question 18

Multiple sclerosis (caused by viral infection, treated w interferons) causes an increase in what?

Answer 18

Cytokines that activate sphingomyelinase

–> excessive degradation of myelin sheath (neurodegenerative)

Question 19

Cystic fibrosis involves a defect in

Answer 19

Cl- channel

–> Cl- can’t leave the cell, so it pulls water in with it, thus engorging the cell to become thick and sticky

Question 20

Cystinuria

Answer 20

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

Question 21

Statins enhance endocytosis of LDL from the blood. Endocytosis of LDL differs from phagocytosis how?

Answer 21

It uses clathrin-coated pits because it’s a receptor mediated endocytosis

Question 22

Primary cilia

Answer 22

Are on every cell; they are nonmotile; lack dynein; and don’t have a central microtubule pair (9+0 arrangement)

May act as receptors

Question 23

What do you call the bridges linking microtubule pairs of an axoneme

Answer 23

Nexin

Note: Axoneme = 9+2

Question 24

The most abundant protein in the cell cortex cross-linked with actin is

Answer 24

filamin

Important for actin’s role in cell-cell junctions

Question 25

For cilia and flagella to move (**microtubules**), **dynein** has to use \_\_ For actin to produce contracitle forces , **myosin** has to use \_\_\_

Answer 25

Both have to use **ATP**

Question 26

Aggresomal response

Answer 26

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**)

Question 27

Kartagener's syndrome

Answer 27

Defective microtubules can't mobilize cilia --\> sperm immotility, infertility in women, messed up respiratory system

Question 28

Colchicine

Answer 28

Prevents tubulin polymerization so that neutrophils can't migrate to urate crystal deposits during **gout**

Question 29

**Vinblastine & Vincristine(Oncovin)** vs **Paclitaxel/Taxol**

Answer 29

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.

Question 30

**Cytochalasin B**, and **cytochalasin D** from fungi

Answer 30

Prevents actin polymerization at the + end --\> inhibits lymphocyte migraiton, phagocytosis, and cell division

Question 31

**Phalloidin** from poisonous mushrooms

Answer 31

Stabilize actin filaments from depolymerizing --\> cell death

Question 32

Mutations in neurofilaments are common in what disease

Answer 32

Alzheimer's ; forms **neurofibrillary tangles**

Question 33

Mutations in the GFAP gene that give rise to masses of GFAP that interfere with astrocyte mitosis. What disease?

Answer 33

**Alexander disease** Leukoencephalopathy, macrocephaly, seizures, psychomotor impairment, death as a child

Question 34

**Mallory bodies**: Eosinophilic intracytoplasmic inclusions composed of **keratin intermediate filaments** What does a build up of these indicate?

Answer 34

Alcoholic liver cirrhosis

Question 35

Nuclear import or export requires

Answer 35

GTP hydrolysis

Question 36

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

Answer 36

apoptosis

Question 37

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

Answer 37

Necrosis

Question 38

Paraptosis

Answer 38

Induced by growth factor receptors (like insulin) Mediated by **MAPK**'s Forms multiple large vacuoles and swollen mitochodnria

Question 39

Pyroptosis

Answer 39

Induced by infection Mediated by **caspase-1**, which activates **IL-1** and **IL-18** --\> inflammation

Question 40

Start/restriction checkpoint

Answer 40

Occurs right before S

Question 41

G₂/M checkpoint

Answer 41

Ensures that DNA replication is complete

Question 42

Spindle checkpoint

Answer 42

During metaphase Ensures that all chromosomes will be segregated

Question 43

**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?

Answer 43

Myoclonic epilepsy with ragged red fibers (an example of mitochondrial cytopathy

Question 44

What enzyme is deficient in Tay-sachs, resulting in a build up of gangliosides?

Answer 44

Hexosaminidase A

Question 45

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?

Answer 45

Zellwegger

Question 46

Vesicle of a Golgi apparatus that is destined to become part of other organelles is likely to have what on their membrane?

Answer 46

COPII for intracellular anterograde transport