Micro Medicine - Exam 1

Front 1

Actin

Back 1

Structural microfilaments, composed of F actin

Front 2

F Actin

Back 2

G actins polymerized into a double helix

Front 3

Microfilaments

Back 3

Actin and myosin

Front 4

G actin

Back 4

monomeric actin subunits

Front 5

Tropomyosin

Back 5

a regulatory alpha-helix in muscle, that wraps around F actin myofilaments

Front 6

Troponins (C, T, I)

Back 6

Regulatory subunits that respond to Ca2+ to interact with tropomyosin and induce muscle contraction

Front 7

Spectrin

Back 7

actin crosslinking protein that forms networks in erythrocytes

Front 8

Dystrophin

Back 8

actin crosslinking protein that forms networks in striated muscle (Duschenne muscular dystrophy is a sex linked mutation of the dystrophin gene)

Front 9

Myosin

Back 9

a structural microfilament as well as a motor protein for actin

Front 10

Actomyosin

Back 10

actin and myosin associated with eachother

Front 11

Stress fibers

Back 11

bundles of actomyosin anchored to the basal surface of fibroblasts, which are themselves attached to the substratum. These fibers produce tension across a cell layer.

Front 12

Microtubules

Back 12

polymers of alpha and beta tubulin

Front 13

Tau and MAPs (Microtubular Associated Proteins)

Back 13

microtubular crosslinking proteins that form networks

Front 14

Dynein

Back 14

a microtubular motor protein for flagella, cilia, axons, and kinetochores

Front 15

Intermediate Filaments

Back 15

structural components of the cytoskeleton. Intermediate filaments are complexes composed of proteins that all have similar alpha helical cores, but distinctive terminal domains

Front 16

Keratin

Back 16

a major intermediate filament of epithelial cells. (Hair and nails consist of dead epithelial cells, mostly composed of keratin)

Front 17

Nuclear Lamins

Back 17

Intermediate filaments supporting the nuclear membrane

Front 18

Collagens

Back 18

extracellular matrix fibers that resist stretching, composed of 3 helices coiled around each other in a triple helix

Front 19

Elastin

Back 19

stretchable extracellular matrix fibers that provide tissue with pliability

Front 20

Fibrillin

Back 20

glycoprotein microfibrils that provide a scaffold for assembly of elastic fibers

Front 21

Glycosaminoglycans

Back 21

polysaccharides of the extracellular matrix composed of disaccharide repeats of modified sugars

Front 22

Hyaluronans

Back 22

a particularly large glycosaminoglycan that exists free in the cellular matrix

Front 23

Proteoglycans

Back 23

extracellular matrix components, composed of core proteins attached to one or more glycosaminoglycans

Front 24

Heparin

Back 24

a regulatory proteoglycan that controls inflammation

Front 25

Laminin

Back 25

extracellular matrix crosslinking protein forming networks in the basal lamina

Front 26

Fibronectin

Back 26

extracellular matrix crosslinking protein with multiple binding domains for different factors (heparin, collagen, integrin, etc.)

Front 27

Integrin

Back 27

The transmembrane protein for hemidesmosomes and adhesion plaques. It is bound by an adaptor protein or plaque on the cytoplasmic side of the membrane and fibronectin on the extracellular side.

Front 28

Ankyrin

Back 28

a membrane-microfilament binding protein that binds spectrin in erythrocytes and desmin from muscle sarcomeres

Front 29

Adaptor Proteins

Back 29

factors that link actomyosin filaments to integrin in adhesion plaques or cadherin in belt desmosomes

Front 30

Cadherins

Back 30

A family of calcium dependent transmembrane proteins that tie similar cells together. One of the cadherins is used in belt desmosomes.

Front 31

Spot desmosomes

Back 31

isolated "spot welds" joining the intermediate filament cytoskeletons of two cells at their lateral surfaces

Front 32

Hemidesmosomes

Back 32

Structures that anchor the intermediate filament cytoskeleton of an epithelial cell to the basal lamina

Front 33

Membrane-microfilament binding protein

Back 33

membrane associated proteins that anchor the microfilament cytoskeleton to the plasma membrane by binding actin crosslinking proteins

Front 34

Adhesion Plaques

Back 34

structures that anchor microfilament stress fibers to the basal surface of many cells, particularly epithelial cells.

Front 35

Zonula Occludens

Back 35

Thin bands of membrane around the apical perimeter of epithelial cells, held closely together by proteins such as occludin and claudin. They seal cells to prevent diffusion of molecules across the epithelium.

Front 36

Zona Adherens

Back 36

Rows of structures anchoring actin microfilaments to the apical surface of epithelial cells, just beneath the tight junction

Front 37

Circumferential Belt

Back 37

Microfilament bundles (actin and myosin) that encircle the apical perimeter of epithelial cells at the level of the belt desmosomes

Front 38

Gap Junctions

Back 38

Transmembrane complexes that allow diffusion of small molecules between cells to vessicles

Front 39

Nucleoplasm

Back 39

All material within nuclear membrane

Front 40

Poidy

Back 40

The number of sets of chromosomes in a cell. Somatic Cells have 2N, which is 23 sets of chromosomes. Haploid cells are 1N.

Front 41

Karyokinesis

Back 41

Nuclear division. Begun in prophase, completed in telophase.

Front 42

Leptonema (Leptotene Phase)

Back 42

spindle formation, chromosomal condensation, and nuclear membrane dissociation all begin. Sister chromatids already tied together into bipartites.

Front 43

Zygonema (Zygotene Phase)

Back 43

Synapsis begins. Synaptonemal complexes form, holding tetrads together along their lengths.

Front 44

Pachynema (Pachytene Phase)

Back 44

Synapsis complete, holding homologs together as parallel strands. Crossing over occurs. The synaptonemal complexes move down the bivalents, exchanging DNA strands and randomizing the combination of paternal and maternal genes along each chromatid.

Front 45

Diplonema (Dipletene Phase)

Back 45

Homologs repel eachother. Chisasma becomes visible where the homolgs are still help by synapsis. Synapotnemal complexes move to the ends the chromosomes and dissociate. In mammalian females, oocytes arrest for years waiting for a menstrual cycle.

Front 46

Diakenesis

Back 46

All chiasma released by dissociation of synaptonemal complexes. Chromosome condensation completed, so that the four chromatids appear as discrete units. Spindle formation and nuclear membrane breakdown completed. Tetrads move to metaphase plane.