Exam 4 Lecture 43 stem cells Flashcards Preview

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Flashcards in Exam 4 Lecture 43 stem cells Deck (24):
1

Qualities of stem cells

1. Are NOT terminally differentiated
2. Can continue to divide without limit
3. Are self-renewing (i.e., one of the daughter cells remains as a stem cell)

2

What special capability do stem cells have?

They can regenerate tissue over a lifetime

3

Potencies of stem cells (5)

totipotent, pleuripotent, multipotent, oligopotent, unipotent

4

totipotent

Can make every kind of cell

5

pleuripotent

Can make almost any kind of cell

6

multipotent

Can make multiple but limited cell types

7

oligopotent

Can make a few cell types

8

unipotent

Makes only one kind of cell

9

Transit amplifying cell

daughter cell destined for differentiation

10

When does transit amplifying cell divide?

It may divide multiple times before differentiation. It often divides more rapidly than a step cell.

11

Animal body plans are generated from

Embryonic stem cells

12

Regeneration and renewal of tissues/body parts depends on

Adult stem cells

13

Two types of asymmetric cell division

Intrinsic (divisional) and extrinsic (environmental)

14

Intrinsic asymmetry

Involves segregation of certain molecules to one side of the cell so that resulting daughter cells receive unequal amounts of those molecules

15

Why internal polarity in stem cell

Asymmetrical distribution of molecules within cell

16

centrosomes and intrinsic asymmetry

Distributed asymmetrically to daughter cells
Younger centrosomes causes differentiation

17

Stem cell niche

microenvironment around stem cells that provides support and signals; regulates self-renewal and differentiation

18

Why might some cancer cells survive radiation?

May be slowly dividing stem cells

19

Transit amplifying cells

From stem cells and divide a discrete number of times. Progeny differentiate.

20

ABC transporters

Pump drugs out of cells. Cancer cells may have a lot of these, so can avoid medication.

21

Why are cancer stem cells resistant to anti-cancer to drugs?

abc transporter and low rate of cell division

22

Oct4 and Sox2

Transcription factors that function in maintaining pluripotency in both early embryos and ES cells

23

c-Myc and Klf4

Transcription factors that modify chromatic structure so that Oct4 and Sox2 can bind to their target. c-Myc controls cell proliferation.

24

Producing induced pluripotent stem cells (iPS)

Transcription wave 1
Activate OSKM expression
Differentiated fibroblast
Loss of fibroblast specific marker protein
Transcription wave 2
Gain of embryonic marker protein
Endogenous OCT4 gene switched on