Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

HISTO - Exam 1 > Lecture 1 - Cell & Cell Reaction > Flashcards

Lecture 1 - Cell & Cell Reaction Flashcards

1
Q

What is the resolution of LM? TEM? SEM?

A

LM - 0.2 uM
TEM - 1nM
SEM - 2nM

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is the size of an RBC?

A

7.0uM (used as a reference)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

How thick is a paraffin section on a typical glass slide?

A

5-12uM

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is the diameter of an average virus?

A

0.02-0.09uM

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What are the steps and reagents in specimen prep for LM?

A

1) Fixation - 10% neutral buffered formalin (formaldehyde stabilized with methanol)
2) Dehydration - w/ alcohol
3) Rinsing with xylene or chloroform
4) Infiltration with paraffin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Explain H&E.

A

Hematoxylin - purple/blue, Basophilic, stains proteins

Eosin - red/pink, acidophilic, stain cytoplasm, collagen, elastic fibers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is formaldehyde used for?

A

The aldehydereactive group crosslinks proteins.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is the structure of formaldehyde?

A

CH2=O

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is the most common fixative for EM?

A

Glutaraldehyde

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is the function and mechanism of glutaraldehyde?

A

Crosslinks proteins by forming methylene bridges between polypeptides at reactive side groups. Preserves proteins and nucleoproteins well. Slight rxn w/ lipids.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is the first step following fixation for TEM specimen prep?

A

Tissue must be post-fixed in osmium tetroxide

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is the function of osmium tetroxide?

A

Osmium tetroxide is a harsh oxidative agent that preserves membrane and lipid components.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is used for dehydration in TEM specimen prep? infiltration?

A

Dehydration: alchohol and acetone Infiltration: epoxy resin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

How are specimens stained for TEM?

A

With heavy metals (ex uranium, lead salts). These will provide contrast in EM.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What contains the surface detail information for EM?

A

Secondary electrons: electrons that are low energy emitted from the surface of the specimen (up to a depth of 20A).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What step follows fixation for SEM?

A

Dehydration with ETOH and critical point drying

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What step follows drying for SEM?

A

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

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Explain the typical procedure for immunocytochemistry visualization?

A

1) Block non-specific protein binding with a protein solution
2) Incubate w/ primary antibody
3) Incubate w/ secondary antibody that contains a visualization label

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is the charge of an acidic dye and what is the charge of the molecule it will stain?

A

Na+dye- (acidic dye is negative)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is the charge of a basic dye and what is the charge of the molecule it will stain?

A

Cl-dye+ (basic dye is positive)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What does Periodic acid Shiff (PAS) stain bind?

A

Glycogen and various carbohydrate containing molecules

22
Q

What does Silver stain bind?

A

Reticular fibers (which are Type III collagen)

23
Q

How thick is a standard lipid bilayer?

A

7-10nM

24
Q

What makes up a cellular membrane?

A

phospholipids, glycolipids, cholesterol

25
Q

What are gangliosides? Where are they abundant?

A

Glycolipids with sialic acid (9-carbon monosaccharide) containing oligosaccharides. Abundant in nerve tissue.

26
Q

What is the cell surface receptor for cholera toxin and diphtheria toxin?

A

GM1 ganglioside

27
Q

Where is GM1 located?

A

It is asymmetrically distributed in outer membrane leaflet.

28
Q

Define glycocalyx.

A

“Sugar coat” commonly associated with the extracytoplasmic aspect of the outer leaflet of the plasma membrane.

29
Q

Define glycosaminoglycans.

A

Negatively charge polysaccharides

30
Q

Define proteoglycans.

A

Heavily glycosylated glycoproteins.

31
Q

What are the functions of the glycocalyx?

A
  • Cellular attachment to extracellular matrix components
  • Binding of antigens and enzymes to cell surface
  • Facilitating cell-cell recognition and interaction
32
Q

What percentage of the cell membrane is made up by cholesterol?

A

2%

33
Q

What is the role of cholesterol in the cell membrane?

A

Assists in maintaining membrane structural integrity by decreasing mobility of first few CH2 groups on phospholipids. Keeps phospholipid bilayer from becoming too fluid or too rigid (crystallizing).

34
Q

When a freeze fracture is completed which membrane/ face do most proteins stick to?

A

P-face (protoplasmic face) - the external surface of the inner leaflet

35
Q

What is GLUT1 and what form of glucose does it accept?

A

GLUT1 - a multipass transmembrane protein. It is stereospecific accepts D- but not L-glucose

36
Q

Where are Na+ and Cl- more concentrated (inside or outside cell) and what is the factor by which they are concentrated?

A

Outside cell, 10-20X concentrated.

37
Q

Where is K+ concentrated (inside or outside cell) and what is the factor by which they are concentrated?

A

Inside cell, 20-40X concentrated.

38
Q

How does Oubain inhibit the Na+/K+ pump?

A

It binds to the K+ site and stops the function (cycling) of the enzyme.

39
Q

How is glucose transported through the intestinal epithelium?

A

Na+ flows down its gradient and “drags” glucose with it. Receptor on epithelial cells in intestinal lumen binds Na+ and glucose and then changes conformation. At basal side glucose moves down concentration gradient and passively exits through glucose specific carrier.

40
Q

What is the significance of malignant cell over-expression of 170kD ATPase (P170).

A

These cells can utilize ATP and pump anticancer drugs out more effectively/quicker.

41
Q

What causes cystic fibrosis?

A

Defective CFTR, which is an ATP and cAMP sensitive Cl- channel. In cf patients CFTR is insensitive to cAMP and Cl- flux across the membrane does not occur.

42
Q

What type of receptors are nicotinic acetylcholine receptors?

A

Ion channel-linked receptors

43
Q

What is the common mechanism of catalytic receptors and what are some examples of catalytic receptors?

A

Single pass transmembrane protein that bind ligand and internal aspect becomes active kinase. Examples include receptors for insulin, EGF, PDGF.

44
Q

What is the general role of:

  • Gs proteins
  • Gi proteins
  • Gp proteins
A

Gs: stimulatory (ex activate adenyl cyclase)
Gi: Inhibitory
Gp: Activate phospholipase C

45
Q

What ion channel is blocked to treat hypertension?

A

Calcium channels (calcium channel blockers)

46
Q

What ion channel is blocked to treat epilepsy (seizures)?

A

Sodium channel (sodium channel blockers)

47
Q

What ion channel is blocked to treat type II diabetes?

A

Potassium channel (glipizide)

48
Q

Toxin that inactivates Na+ channels (occupies Na+ binding sites). Leads to dizziness, tingling about mouth, respiratory failure, death.

A

Tetrodotoxin

49
Q

Alters Gs protein so they cannot hydrolyze GTP

A

Cholera toxin

50
Q

What is the effect of faulty Gs proteins?

A

Mental retardation / diminished growth / diminished sexual development

51
Q

Hereditary condition due to abnormal carrieor proteins that cannot remove cystine from the urine - produces kidney stones.

A

Cystinurea

52
Q

Autoimmune disease where IgG antibodies bind to TSH receptors and stimulate thyroid follicular cell constitutively. This leads to enlarged thyroid, eyeball protrusion.

A

Graves disease

HISTO - Exam 1 (7 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions