Lesson 4 Video

mcat5122018
Posts: 17
Joined: Sat Mar 03, 2018 3:33 pm

Lesson 4 Video

Postby mcat5122018 » Sat Apr 14, 2018 10:27 pm

Hi,

Can you please explain number 16 in lesson 4? I understand the concept of DNA replication, but for some reason I tend to get confused with the directions when it comes to which side the DNA strand is being opened and replicated. When Dr. Anthony explained it I understood it, but I also think I over-thought the question because in the passage it stated that DNA polymerase adds only to the 3' end of nucleotides. What is the best way to memorize or learn this to effectively remember the concept without getting confused or reading too much into it?

Can you also explain number 22? The explanation was confusing. The question is talking about dsDNA's resistance to heat denaturation. I did not understand why its resistance to heat denaturation increases in the presence of salts.

Thank you.
NS_Tutor_Andrew
Site Admin
Posts: 520
Joined: Mon May 23, 2016 1:47 pm

Re: Lesson 4 Video

Postby NS_Tutor_Andrew » Mon Apr 16, 2018 3:40 pm

Hi mcat5122018,

Looks like I might have responded in another thread, but I'll copy it here too (sorry for the delayed response to the original post):

For #16, I tend to think that the direction of synthesis & lagging/leading strands is one of those things that is much easier to understand when you visualize it than when you read about it. Here's a link to a video that might be useful, but by all means, feel free to keep looking -- there are TONS of videos out there on science concepts and you never know which one might present it in a way that "clicks" for you. I also recommend drawing it out a few times physically to build that kinesthetic connection with the concept.

Re: the question on dsDNA denaturation, the basic idea is that the charge-based interactions with salts help to stabilize the DNA.

Hope this helps clarify those questions, and thanks for checking in!
Andrew D.
Content Manager, Next Step Test Prep.

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