Save
Busy. Please wait.
or

show password
Forgot Password?

Don't have an account?  Sign up 
or

Username is available taken
show password

why


Make sure to remember your password. If you forget it there is no way for StudyStack to send you a reset link. You would need to create a new account.
We do not share your email address with others. It is only used to allow you to reset your password. For details read our Privacy Policy and Terms of Service.


Already a StudyStack user? Log In

Reset Password
Enter the associated with your account, and we'll email you a link to reset your password.
focusNode
Didn't know it?
click below
 
Knew it?
click below
Don't know
Remaining cards (0)
Know
0:00
share
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.

  Normal Size     Small Size show me how

Spectrophotometry

QuestionAnswer
What is Spectroscopy? It is the branch of physical science involved with the measurement of the spectra, has had a profound role in the conversion of biology from the purely descriptive to more quantitative measurements
Why measurements of the absorbance of light by substances in solution are used in biochemistry? Because many compounds of interest to biochemist absorb light in the ultraviolet, visible, or near infrared region.
What is a typical application of spectroscopy in biological research? It is the measurement of the concentration of a substance (i.e. protein or nucleic acid) present in a solution based on the amount of visible or ultraviolet light absorbance by the substance.
What is a spectrophotometer? It is an instrument that is designed to measure the absorbance of light.
In what consists the spectrophotometer? It consists of a light source (usually white light or ultraviolet light) which is focused on a prism or other light-dispersive device.
what is the function of the prism? The prism is designed to separate the white light into separate bands of radiant energy. Each different wavelength is selectively focused through a a narrow slit. This beam of light, called the incident beam, passes through the sample to be measure
What happens after the beam of light traverse the sample? It emerges as the transmitted beam and strikes a photoelectric cell. If the substance has absorbed any of the incident light, the transmitted light will be reduced in the total energy content.
What happens when the transmitted light strikes the photoelectric cell? It generates an electric current that is proportional to the intensity of the light striking it.
What does the Beer's law state? The concentration of a light-absorbing solute is directly proportional to the absorbance over a given range of concentrations. a straight line is generated after plotting absorbance vs sample concentration
What is the use of the blank? The blank contains the solvent where the biological molecules will be dissolve in order to avoid that the solvent itself absorbs light.
What is an absorption spectrum? It shows the wavelengths of maximum absorption for the substance being studied
Why should a concentration curve be made at the Amax wavelength for a given compound? A concentration curve should be made at the maximum wavelength for a given compound because the sample is most sensitive to concentration changes; therefore, the change in concentration will be measured more accurately.
How can a concentration curve be used to determine the molarity of a solution of unknown molarity? by using the absorbance of the known solutions at the maximum wavelength in conjunction with the concentrations to obtain a function describing the relationship among the variable. That functions can then be used to find the concentration of the unknown.
Created by: daysivp
 

 



Voices

Use these flashcards to help memorize information. Look at the large card and try to recall what is on the other side. Then click the card to flip it. If you knew the answer, click the green Know box. Otherwise, click the red Don't know box.

When you've placed seven or more cards in the Don't know box, click "retry" to try those cards again.

If you've accidentally put the card in the wrong box, just click on the card to take it out of the box.

You can also use your keyboard to move the cards as follows:

If you are logged in to your account, this website will remember which cards you know and don't know so that they are in the same box the next time you log in.

When you need a break, try one of the other activities listed below the flashcards like Matching, Snowman, or Hungry Bug. Although it may feel like you're playing a game, your brain is still making more connections with the information to help you out.

To see how well you know the information, try the Quiz or Test activity.

Pass complete!

"Know" box contains:
Time elapsed:
Retries:
restart all cards