Spectrophotometric Determination of Nucleic Acid Concentration Flashcards

1
Q

The range of all possible EM radiation

A

Electromagnetic waves

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

the spectrum of different wavelengths that eyes recognize as white

A

light

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

Electromagnetic waves are of _____ and waves

A

photons

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

Part of the EM spectrum that can be seen by the naked eye

A

visible spectrum

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

which waves are in the right of the visible light in the spectrum, these are characterized to have longer wavelengths

A

infrared, microwave, and radiowaves

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

t or f

shorter wavelengths are less harmful than longer wavelengths

A

F (high frequency, shorter wavelength = more harmful)

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

which waves are found at the left of visible light, these are characterized to have a higher frequency

A

gamma ray, x-ray, and ultra violet rays

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

Should we be more wary of waves that are higher or lower in frequency?

A

higher frequency (shorter waves)

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

an optical instrument for measuring the intensity of light in any specific wavelength related to solution concentrations

A

spectrophotometer

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

In what section of the lab are spectrophotometers used to measure the concentration of an analyte

A

clinical chemistry

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

T or F

spectrophotometers enable for a qualitative analysis of the substance only

A

F (quali and quanti)

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

Before measuring the analyte using a spectrophotometer, what do you measure first for control purposes?

A

blank / reference cell

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

What should be the result of the blank or reference cell?

A

zero

100% transmittance and 0% absorbance

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

the measure of the capacity of a substance to absorb light of a specific wavelength

A

absorbance / optical density

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

the measure of how much light passes through a substance

A

Transmittance

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

what formula is this for?

A

transmittance

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

what formula is this for?

A

Absorbance

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

A mathematic relationship that is the basis of analysis in spectrophotometry

A

beer’s law

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

T or F

In beer’s law, the concentration of the substance is inversely proportional to the amount of light absorbed

A

F (proportional)

directly proportional

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

T or F

Beer’s law states that the concentration of the substance is inversely proportional to the logarithm of transmitted lights

A

T

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

this produces intense reproducible constant beam of light, where everything starts

A

light source

22
Q

T or F

White light contains all of the wavelengths

23
Q

What is the type of light source for UV region

A

deutrium lamp

Deutrium (high-pressure hydrogen) lamp

24
Q

what is the most common light source for visible and infrared rays regions

A

Tungsten - halogen

25
What is the component of the spectrophotometer that makes it so that all of the light beams are parallel to each other
collimator
26
This is a system for isolating radiant energy of a desired wavelength and excluding that of other waves
monochromator / diffraction grating
27
T or F When you change the light source, the machine should be calibrated
T
28
Why should you recalibrate the machine when you change the light source?
because the angle of the light shining in the monochromator also changes
29
T or F the monochromator flashes all of the wavelengths
F (you can select the specific wavelength of your chosen analyte)
30
T or F prisms achieve dispersion due to the difference in the material refracted index according to its wavelength
T
31
What does diffraction grating use to split the light?
difference of diffraction direction due to interference
32
prism or diffraction grating? can be made to spread colors over a larger angle
diffraction grating
33
prism or diffraction grating? more sensitive to the color of the light
prism
34
A small vessel used to hold a liquid sample to be analyzed in a spectrophotometer
Cuvettes
35
What shapes do cuvettes come in?
round, square, or rectangular
36
What materials are cuvettes constructed from?
glass, silica, or plastic
37
What type of cuvette is used for UV range
quarts
37
Why do we discard the cuvette if it becomes scratched?
the scratch can affect the spectrophotometer reading | the light bounces of the scratches :((
38
what type of cuvette for visible range
glass
39
converts light energy (transmitted by a solution) to an electrical signal
photodetectors
40
simplest photodetectors
photocell and phototube
41
commonly used photodetector for measuring light intensity in the UV and visible region, it’s rapid and very sensitive
photomultiplier tube (PMT)
42
An electrical energy coming out from a detector is displayed on some type of digital display or readout system
readout device
43
in what forms can a readout be
chart, digital display, or a computer printout
44
What are the 2 applications of spectrophotometer
1. Measurement of concentration 2. Detection of impurities
45
Why does nucleic acids absorb uv light
due to the presence of heterocyclic rings in the bases
46
what is the wavelength of maximum absorption for both DNA and RNA
260 nm
47
which characteristic is used to quantify the amount of nucleic acids
amount of absorbed light
48
Wavelength of maximum absorption for detecting proteins and salts
* 280nm - proteins * 230nm - salts
49