week 1 histology ultra structure

Question 1

steps for making histology slide

Answer 1

1. specimen acquisition
2. fixation
3. dehydration
4. embedding
5. section
6. stain

Question 2

why do we do fixation?

Answer 2

to preserve the structure

Question 3

why do we do embedding?

Answer 3

to stiffen it so we can cut

Question 4

why do we do sectioning?

Answer 4

to improve resolution

Question 5

why do we stain?

Answer 5

to produce contrast

Question 6

what is the maximum resolution, magnification and section thickness of a light microscope ?

Answer 6

0.2um, 2000x , 1-100 um

Question 7

what is the max resolution and magnification of the TEM microscope? and then sectioning thickness

Answer 7

3nm , 500,000 x, 0.025 um

Question 8

how thick is plasma membrane?

Answer 8

9nm

Question 9

Nucleus of non-dividing cells contains?

Answer 9

Chromatin

Question 10

Nucleus of dividing cells contains? (mitosis)

Answer 10

Chromosomes

Question 11

What is chromatin comprised of?

Answer 11

DNA + Histones

Question 12

What is Euchromatin?

Answer 12

DNA wraps around histones forming NUCLEOSOMES. light areas.

Question 13

What is Heterochromatin?

Answer 13

Multiple nucleosomes wrap to form a 30nm CHROMATIN FIBRE.

Question 14

Euchromatin features?

Answer 14

Pale areas, active, extended

Question 15

Heterochromatin features?

Answer 15

Dark areas, condensed, inactive.

Question 16

Cytoskeleton functions?

Answer 16

Structural support, intracellular movement of organelles & metabolites

Question 17

What are non-membranous organelles?

Answer 17

Microtubules, microfilaments, intermediate filaments

Question 18

What is the function of Microtubules?

Answer 18

Intracellular transport, cell shape, cilia movement, chromosome arrangement

Question 19

T or F: Microtubules are stable and do not continuously change shape.

Answer 19

F: Continually forming & disassembling

Question 20

What disrupts microtubules?

Answer 20

Drugs, decrease temp, increase hydrostatic pressure

Question 21

What is the structure of Microtubules?

Answer 21

Tubulin protein, hollow cylinders, 22n, diameter, 5nm thick walls, dynamic

Question 22

What is the structure of microfilaments?

Answer 22

Actin, helical array, 6nm diameter, flexible

Question 23

T or F: Microtubules are arranged in a helical structure.

Answer 23

False: arranged in hollow cylinders.

Question 24

Function of microfilaments?

Answer 24

Microvilli structure, extension of cell processes

Question 25

Which organelle initiates apoptosis via release of cytochrome c into the cell cytoplasm?

Answer 25

Mitochondria