Cell Bio Lecture 36

Front 1

degree of attachment predicts

Back 1

probability of division

Front 2

probability of entering s phase if suspended in agar

Back 2

8%

Front 3

perch on a small adhesive patch

Back 3

30%

Front 4

spread on a big adhesive patch

Back 4

90%

Front 5

cell division depends on ____

Back 5

cell shape and anchorage

Front 6

exception:

Back 6

some cells will divide readily in suspension
i.e. blood cell precursors

Front 7

what else affects cell division besides degree of attachment?

Back 7

cell density and nutrients

Front 8

where aren't the majority of cells in your body?

Back 8

not in suspension

Front 9

focal contacts:

Back 9

sites of production of intracellular signals
-there is a heterodimeric integrin that are sites of production for intracellular signals

Front 10

how do cells know how attached they are?

Back 10

by the proteins containing phosphotyrosine

Front 11

how growth and proliferation are generated by cell attachment

Back 11

proteins containing phosphotyrosine are also concentrated at these sites. This is thought to reflect the operation of a tyrosine-kinase intracellular signaling mechanism

Front 12

the operation of a tyrosine-kinase intracellular signaling mechanism is activated by

Back 12

transmembrane integrin proteins that bind to fibronectin extracellularly and indirectly to a cytoskeletal element

Front 13

what are the goals of m-phase

Back 13

mitosis and cytokinesis
-accurately partition DNA of daughter cells
-accurately partition cell contents to daughter cells; organelles, cytosol, membranes

Front 14

stages of mitosis

Back 14

prophase
prometaphase
metaphase
anaphase A
anaphase B
telaphase
cytokinesis

Front 15

prophase

Back 15

centrosome separation
DNA condensation
nuclear envelope not yet broken down
could microtubules access?

Front 16

prometaphase

Back 16

NEB
spindle formation

Front 17

metaphase

Back 17

congression: movement to middle of cell
-chromosomal alighment
-the pulling and pushing are not equal at this point
-the forces of the MT would not be able to line up in the middle if this were the case

Front 18

anaphase

Back 18

movement back towards the poles
chromatid separation
-there is a biochemical pause
-you need to cut the piece of protein (cohesive) that is holding the metaphase and anaphase together
-spindle elongation
-MT motors near poles

Front 19

telaphase

Back 19

-chromosome decondensation
-nuclear membrane reformation
-position of midline determines the info for where the midline will form
at a 90 degree angle at healthy cells

Front 20

stages of mitosis again
prophase

Back 20

centrosome separation
DNA condensation

Front 21

prometaphase

Back 21

NEB
spindle formation

Front 22

metaphase

Back 22

congression
chromosome alignment

Front 23

anaphase A

Back 23

chromatid separation

Front 24

anaphase B

Back 24

spindle elongation

Front 25

telophase

Back 25

chromosome decondensation
nuclear membrane reformation

Front 26

cytokinesis

Back 26

division into 2 cells

Front 27

how long does it take for mitosis to occur?

Back 27

80 minutes

Front 28

why is metaphase the longest of the all the portions in mitosis?

Back 28

this is where u have abrupt biochemical change
such as checkpoints for alignment, etc.

Front 29

DNA condensation or compaction

Back 29

chromosomes of this early prophase nucleus have begun the process of compaction that converts them into short, rodlike mitotic chromosomes that separate at a later stage in mitosis

Front 30

dna condensation and compaction again

Back 30

very first morphological change that you see in mitosis
-first signal that mitotis is going to begin
-these chromosomes have shrunk by 40-50 fold

Front 31

each mitotic chromosomes is comprised of a ___

Back 31

pair of sister chromatids connected to one another b the protein complex Cohesin

Front 32

activates the cleavage of this, helps phosphorylate some things in order to release and drive this separase

Back 32

m-cdk

Front 33

the scanning EM of several human metaphase chromosomes showing the

Back 33

paired identical chromatid length and join tightly at the centromere. The chromatids are not split apart from one another

Front 34

cohesions and condensins help

Back 34

configure replicated chromosomes for segregation

Front 35

condensin is 2 _____

Back 35

paired proteins

Front 36

in order for condensin to do its job,

Back 36

ATP needs to be cleaved

Front 37

cohesin is what makes these things ___

Back 37

sticky

Front 38

condensin helps

Back 38

coil and compact them
-similar structures, different jobs

Front 39

sister-chromatid cohesion by cohesin

Back 39

crosslink 2 strands

Front 40

dna coiling by condensin

Back 40

intramolecular crosslink to cell

Front 41

formation of mitotic chromosome by a process called

Back 41

compaction or chromosome condensation

Front 42

topoisomerase II (enzyme) to help

Back 42

coil or compact together this DNA to create this chromosome

Front 43

compaction, ____ this is required but its role is unclear

Back 43

H3

Front 44

topoiso II wraps the DNA into

Back 44

positively supercoiled loops that can be compacted into a mitotic chromosome

Front 45

microtubules and MT motors

Back 45

spindle formation and function
karyokinesis

Front 46

actin-myosin:

Back 46

ring around equator, is what helps mediate cytokinesis

Front 47

centrioles

Back 47

specialized structures that get called many different names, they are type of MTOC

Front 48

s-phase leads to duplicated centriole, thus before you enter M-phase, there are now

Back 48

2 pairs of centrioles
at 90 degree angles

Front 49

centriole replication

Back 49

the mother chromosome
g1 separation
s duplication
m elongation

Front 50

what are asters?

Back 50

structures with little MT on them (MT radial array)

Front 51

laminas
-2 goals

Back 51

give shape to nuclear envelope
teather chromosomes to nuclear envelope

Front 52

NEB

Back 52

m-cdk phosphorylates nuclear laminas

Front 53

NEB leading to...

Back 53

MT interact can now access/interact with condensed chromosomes for the 1st time

Front 54

attachment occurs via

Back 54

kinetochore

Front 55

mitotic spindle assembly and function depend on

Back 55

MT-dependent motor proteins
kinesin (+)
dynein (-)

Front 56

kinetochore act _____

Back 56

directly
-all MT motors trying to make spindle longer, they help crosslink MTs in such a way to link + ends

Front 57

overlap zone, MAPs crosslink MT in a way that

Back 57

caps their plus ends

Front 58

3 types of MTs

Back 58

astral MT
kinetochore MT
overlap MT