Lecture 1 Flashcards Preview

Biology 201 > Lecture 1 > Flashcards

Flashcards in Lecture 1 Deck (32)
Loading flashcards...
1
Q

What does the cell theory state?

A

All organisms consist of one or more cells, the cell is the basic unit of structure, and all cells come from preexisting cells.

2
Q

What are the two groups of cells?

A

Prokaryotic and Eukaryotic.

3
Q

What is the difference between prokaryotic and eukaryotic cells?

A

Prokaryotic cells have no nucleus or membrane organelles, but eukaryotic cells do.

4
Q

What kind of microscopy is required to view plant cells, animal cells, and bacteria?

A

Light microscopy

5
Q

What kind of microscopy is required to view ribosomes and microfilaments?

A

Electron microscopy

6
Q

What is the mathematical formula for resolution?

A

R = 0.61(wavelength)/(numerical aperture)

7
Q

Why is the limit of resolution for light microscopes 200nm?

A

Because the visible spectrum of light ends at 200nm and cannot be used to prove structural details smaller than its own wavelength

8
Q

Describe phase contrast microscopy

A

The refractive index of the specimen determines how bright it appears

9
Q

What is phase contrast microscopy good for?

A

It is good for viewing both intra and extracellular edge details.

10
Q

Describe differential contrast microscopy

A

Light is split into closely spaced beams which generate contrast between the object and its surrounding medium due to differences in the index of refraction.

11
Q

What is differential interference contrast microscopy used for?

A

To view surfaces of objects

12
Q

What is fluorescence microscopy?

A

It can be used to visualize subcellular structures and individual proteins by a flour absorbing a specific wavelength of light and then emitting a wavelength in the visible spectrum.

13
Q

What are the two major kinds of fluorescence microscopy?

A

Immunofluorescence and Green Fluorescent Protein (GFP)

14
Q

Describe immunofluorescence

A

Antibodies (primary) detect and attach to a specific antigen, then a second antibody bound with a fluor (secondary) attaches to the primary antibody

15
Q

What is immunofluorescence used for?

A

To detect and localize proteins in a cell.

16
Q

What is an advantage and disadvantage of immunofluorescence?

A

Advantage: It is very specific and provides good resolution

Disadvantage: it requires fixed specimens

17
Q

Describe GFP

A

A jellyfish gene was cloned and can be added to normal proteins to make them glow.

18
Q

Name advantages and disadvantages of GFP

A

Advantage: allows for real-time localization and time-lapses, can use different colours, and can localize known proteins

Disadvantages: requires complicated genetic engineering

19
Q

What is confocal microscopy?

A

It uses a pinhole laser beam to excite only a small plane of specimen with fluorescent light and gives very crisp images of this section

20
Q

Name the advantages and disadvantages of confocal microscopy

A

Advantage: produces high-resolution images with distinct focal planes

Disadvantage: Takes a long time to scan an entire specimen plane by plane

21
Q

Name the two kinds of electron microscopy

A

Scanning and Transmission electron microscopy

22
Q

What is the difference between light and electron microscopy?

A

Electron microscopy uses a beam of electrons, not light, so it is more focused and gives a higher resolution but requires fixed cells.

23
Q

How does SEM work?

A

It measures the amount of electron scatter of the surface of a heavy-metal coated object. Good for viewing surfaces.

24
Q

How does TEM work?

A

It measures how the electrons scatter as they pass through the specimen. Can use antibody staining. Shows internal structures

25
Q

What is centrifugation?

A

The separation of components in a solution by spinning them. Lower density moves up, higher density moves down.

26
Q

What is electrophosphoresis?

A

The separation of molecules based on size (and sometimes charge).

27
Q

How does SDS-PAGE gel separate proteins?

A

Only by size.

28
Q

How does isoelectric point focusing gel separate proteins?

A

Based on size AND native charge.

29
Q

In gel electrophosphoresis, where do larger proteins get stopped?

A

Closer to the top as it is difficult for them to navigate through the matrix.

30
Q

What are the steps of a western analysis?

A

Blot the gel, expose the filter paper to primary antibody, incubate with secondary antibody, and expose to x-ray film to detect the secondary.

31
Q

What is an example of a western blot?

A

The HIV test which uses a western blot to detect in HIV antibodies are present.

32
Q

What is a western blot used for?

A

It detects specific proteins in a gel.