Cell and Cell Reaction Flashcards Preview

Histology Exam 1 TonyFrim > Cell and Cell Reaction > Flashcards

Flashcards in Cell and Cell Reaction Deck (79):
1

Best possible resolution for human eye?

200 µm

2

Diameter of RBC?

7 µm

3

Fixation in Light Microscopy

10% neutral buffered formalin(formaldehyde stabilized with methanol)

4

Thickness of cell plasma membrane

0.007 µm thick

5

Most common stain in light microscopy

Hematoxylin(blue/purple, basophilic) and Eosin(red/pink, acidophilic)

6

Biopsies

Tissue frozen and frozen sections cut and stained (often with fluorescent tagged antibody)

7

Transmission Electron Microscopy

An electron beam is transmitted through a thin specimen in a manner similar to the way in which visible light is transmitted through a tissue section for LM

8

Major difference between TEM and LM

Electron microscopy uses magnetic lenses to focus electrons and LM uses glass lenses to focus photons

9

Most common fixative in electron microscopy

Glutaraldehyde

10

How does glutaraldehyde work as a fixative?

forms methylene bridges between polypeptides at reactive side groups

11

Following glutaraldehyde fixation, tissue must be post-fixed in...

osmium tetroxide to preserve the membrane and lipid components

12

Dehydration in specimen preparation in TEM

alcohol and acetone and infiltration with epoxy resin

13

To provide contrast in the microscope of TEM

stained with uranium and lead salts

14

Scanning Electron Microscope uses

a beam of electron (1° beam) to scan the specimen surface

15

Main byproducts in SEM as probe scans surface of specimen

secondary electrons, backscatter electrons, x-rays, and photons

16

Secondary electrons are

low energy electrons emitted from the surface of the specimen and contain surface detail information

17

SEM and TEM have the same fixation?

True

18

In SEM, after fixation the specimen is

dehydrated in ETOH and critical point dried

19

CPD

critical point dried

20

After drying in SEM, the specimen is

glued onto specimen stub and given a conductive coating (gold,gold-palladium)

21

Goal of immunocytochemistry

visualize some component(antigen) in a tissue section by means of an antibody usually linked to a fluorescent or colored molecule

22

Procedure for immunocytochemistry

1)Section tissue 2)Block non-specific binging w/ a protein solution 3)Incubate w/primary antibody and rinse 4)Incubate w/ secondary antibody which contains visualization label

23

Acid dyes have a __ charge

-

24

Basic dye has a __ charge

+

25

Hematoxylin

Blue stain-chromatin (DNA), rough ER, basophilic

26

Eosin

Pink stain- cytoplasm, collagen/elastin fibers, acidophilic

27

Standard stain used for tissues in anatomy and physiology

H and E

28

Periodic acid Shiff stain

Stains glycogen and various carbohydrate containing molecules (magenta)

29

Basement membrane of Bowman's capsule in the kidneys stains with

PAS (stains Basement membrane magenta)

30

Basic structural and functional unit

Cell

31

Cells are organized into tissue and tissues are organized into

organs

32

4 primary tissues

Epithelium, Connective Tissue, Muscle, and Nervous tissue

33

Cytoplasm

Organelles and inclusions suspended in cytoplasmic matrix(cytosol)

34

Organelles

Cell systems responsible for synthetic, metabolic, energy requiring and energy generating functions of the cell

35

Thickness of cell plasma membrane

7-10 nm

36

Plasma membrane functions as a

semipermeable membrane between the cytoplasm and outside of the cell

37

Membrane is composed of

phospholipids, glycolipids, and cholesterol

38

Phospholipids possess a polar(hydrophilic) head and two non polar(hydrophobic) fatty acyl tails-so they are called...

amphipathic

39

Glycolipids are

lipids with attached carbohydrates

40

Function of Glycolipids

function in cell-cell and cell-extracellular matrix interactions

41

How are glycolipids distributed

Glycolipids are distributed asymmetrically in outer membrane leaflet

42

Gangliosides

complex glycolipids with sialic acid(9 C monosaccharide) containing oligosaccharides

43

GM1 ganglioside

cell surface receptor for cholera toxin

44

Glycolipids are present only in

outer leaflet and have polar carbohydrate residues that form part of glycocalyx

45

Glycocalyx

"sugar coat" commonly associated with the extracytoplasmic aspect of the outer leaflet of the plasma membrane

46

Glycocalyx composition

Polar oligosaccharides side chains covalently linked to protein and some lipid constituents of the plasma membrane

47

Glycocalyx contain

Proteoglycans, which consist of membrane integral proteins which are bound glycosaminoglycans

48

Functions of glycocalyx

1)cellular attachment to extracellular matrix components 2)binding of antigens and enzymes to cell surface 3)facilitating cell-cell recognition + interaction

49

Cholesterol

assists in maintaining membrane structural integrity by decreasing the mobility of the first few CH2 groups on phospholipids.

50

Cholesterol constitutes

2% of the plasma membrane lipids

51

Two types of membrane proteins

Integral proteins and Peripheral proteins

52

Important membrane property

Fluidity

53

Membrane fluidity increases with

a rise in temperature and by greater unsaturation of the fatty acids in the membrane

54

Membrane fluidity is decreased by an

increase in cholesterol content

55

Glucose will move across a RBC membrane down a conc. gradient via

a glucose transporter protein (GLUT1)

56

GLUT1 is a

multipass transmembrane protein

57

Mechanism for maintaining ion balance in the cell against an electrochemical gradient

NA+ -K+ PUMP

58

Sodium and chloride are

10-20x higher outside than inside the cell

59

Potassium is

20-40x higher inside the cell than outside the cell

60

NA+-K+ pump mechanism

3NA+ OUT.... 2K+ IN (a single ATP is hydrolyzed to complete two steps)

61

What inhibits ion transport in the NA+-K+ pump

Oubain- has the same binding site of K+

62

Sodium-potassium pump acts to

maintain constant cell volume by reducing the ion conc. intracellularly and by increasing it extracellularly- decreasing flow of water into cell

63

Sodium potassium pump plays a minor role in

the maintenance of a potential difference across the plasma membrane

64

Movement of sodium down the e-chem gradient can be

coupled to the movement of other molecules against its concentration gradient

65

Glucose movement across intestinal epithelium works as

cotransported molecule in the same direction as Na+

66

One reason why tumors are often resistant to a broad range of anticancer drugs

tumor cell over expression of ATPase

67

Cystic fibrosis transmembrane regulator (CFTR) has a structure closely related to

MDR-ATPase

68

Cystic fibrosis is due to

defective CFTR in epithelial cell of lung and other tissue

69

What type of chloride ion channel is CFTR

ATP and cAMP sensitive chloride ion channel

70

In CF patients, the CFTR

becomes insensitive to cAMP and Cl- flux across the cell membrane

71

Ion channel proteins

Highly folded transmembrane proteins that form small aqueous pores across membranes - allows specific small, water soluble molecules and ions to pass down gradient

72

Ion channels influence the rate of flow but not

the direction

73

Membrane receptors are primarily

glycoproteins located on cell surface that bind specific signaling molecules

74

Membrane receptors act as

transducers

75

Membrane receptors control membrane permeability by

regulating the conformation of ion channel proteins

76

Ion channel linked receptors

binds a signaling molecule that temporarily opens or closes the gate, permitting or inhibiting the movement of ions across the membrane

77

Catalytic receptors are

single-pass transmembrane proteins. (extracytoplasmic part functions as a receptor and the cytoplasmic part functions as protein kinase)

78

Catalytic receptors may lack

extracytoplasmic part and therefore be continuously activated (oncogenes)

79

Transmembrane trimeric G proteins are composed of what 3 polypeptide subunits

alpha, beta ,gamma