Top Posters
Since Sunday
a
5
k
5
c
5
B
5
l
5
C
4
s
4
a
4
t
4
i
4
r
4
r
4
This topic contains 1 attachment.
Home Q & A Board Biology-Related Homework Help Genetics and Developmental Biology
New Topic  
colleen colleen
wrote...
Go to Answer
Valued Member
Posts: 17077
Rep: 251 1
10 years ago
Assume that you grew a culture of E. coli for many generations in medium containing 15N (from the ammonium ion), a heavy isotope of nitrogen. You extract DNA from a portion of the culture and determine its density to be 1.723 gm/cm3 (call this sample A). You then wash the remaining E. coli cells and grow them for one generation in 14N, extract the DNA from a portion of the culture, and determine its density to be 1.715 gm/cm3 (call this sample B). You let the culture grow for one more generation in 14N and extract the DNA (call this sample C). Each sample of DNA (A, B, and C) is then heated to completely denature the double-stranded structures, cooled quickly (to keep the strands separate), and subjected to ultracentrifugation. Present the centrifugation profiles for heat-denatured DNA (samples A, B, and C) that you would expect. Use the graph below. (Note: Although not the case, assume that single-stranded DNA has the same density as double-stranded DNA.) 
Read 983 times
2 Replies
Sunshine ☀ ☼
Replies
Answer accepted by topic starter
saviosavio
wrote...
#1
Top Poster
Posts: 2168
Rep: 818 8
10 years ago
Sign in or Sign up in seconds to unlock everything for free
 Attached file 
Thumbnail(s):
You must login or register to gain access to this attachment.
1
Biology - The only science where multiplication and division mean the same thing.

Related Topics

wrote...
#2
3 years ago
thank you
New Topic      
Quick Reply
Explore
Post your homework questions and get free online help from our incredible volunteers
  1172 People Browsing
Start New Topic Take the Tour CoursesNew Study Tools Topics Trending Browse by Textbook
Live Chat
Related Images
  
 1826
  
 201
  
 6883
Your Opinion
How often do you eat-out per week?
Votes: 79
Previous poll results: Which 'study break' activity do you find most distracting?