Question 18 options:

Question

Now, let's analyze a substance different from DNA. You have a solution made from the hypothetical substance Z. The constant for substance Z at a wavelength of 600nm is 80 ng of substance Z/μL of solution. Write the equation that you should use to determine the concentration of substance Z if you are given an A600.

Hint: An equation "equates" two entities. If you do not include two things separated by an "=", then you have not written an equation -- you will have simply written a mathematical operation.

Question 19 (2 points)

Using the equation from the previous problem, determine the concentration of substance Z if the A600 is measured to be 0.59.

You may copy/paste the following to indicate "micro"- μ. Please give your answer to one decimal place.

Your Answer:
Question 19 options:

Answer 1

Question 18:

To determine the concentration of substance Z based on its absorbance (A600) at 600 nm, you can use Beer-Lambert Law, which relates absorbance to concentration. The equation can be written as:

\[ A600 = k \times C \]

where:

• \( A600 \) = Absorbance at 600 nm
• \( k \) = constant for substance Z (in units of ng/μL per absorbance unit)
• \( C \) = concentration of substance Z (in ng/μL)

To find the concentration \( C \), you can rearrange the equation:

\[ C = \frac{A600}{k} \]

Given that the constant \( k \) for substance Z is 80 ng/μL, the equation becomes:

\[ C = \frac{A600}{80} \]

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Question 19:

Now, using the equation for concentration derived from Question 18:

Given \( A600 = 0.59 \),

The concentration \( C \) can be calculated as follows:

\[ C = \frac{0.59}{80} \]

\[ C = 0.007375 , \text{ng/μL} \]

To express the answer to one decimal place:

\[ C = 0.0 , \text{ng/μL} \] (since 0.007375 rounded to one decimal place is 0.0)

So, your answer for Question 19 is 0.0 ng/μL.