Log inSign up for FREE
Library

B.6(A) explain the importance of the cell cycle to the growth of organisms, including an overview of the stages of the cell cycle and deoxyribonucleic acid (DNA) replication models

Last updated 11 days ago
13 questions

RELATE: Watch the Amoeba Sisters video on DNA replication to find out about the specifics of what's going on in S phase.

Pay close attention to the names and functions of each enzyme!
Required
1

Match the name of each enzyme with its function.

Draggable itemCorresponding Item
topoisomerase
opens up the DNA, separating the two strands by breaking the hydrogen bonds between their bases
helicase
replicates DNA molecules to make a new complementary strand
primase
lays down RNA primers which allow DNA polymerase to bind to the DNA
ligase
seals the DNA together after replication
DNA polymerase
prevents DNA ahead of the helicase from supercoiling
Required
1

Match the replication terms with their definition.

Draggable itemCorresponding Item
primers
the position on DNA where replication begins
leading strand
special proteins that bind onto the separated DNA strands to ensure they don't come back together
origin
short pieces of RNA that allow DNA polymerase to bind to the separated DNA strands
Single-Stranded Binding Proteins (SSBs)
the two DNA strands run in opposite directions: one from 5' to 3' and the other from 3' to 5'
antiparallel
the new DNA strand that DNA polymerase is continuously synthesizing
Okazaki fragments
the new DNA strand that DNA polymerase is discontinuously synthesizing
lagging strand
DNA fragments formed due to discontinuous DNA synthesis
semi-conservative
after replication is complete, both DNA molecules have one old strand and one new strand.

There's a lot of vocabulary involved in DNA replication!

So, let's see how it might look when it's put all together in a clean, detailed animation. Watch the video and keep in mind all the vocabulary that we just reviewed (plus try to notice the one new enzyme).
Required
1

What is the function of the enzyme exonuclease?

Required
1

What additional step was involved in this animation besides the function of exonuclease?

Required
1

Click on the area where helicase would be located:

Required
1

Click on the area where primase would be located:

Required
1

Click on the area where DNA polymerase would be located:

Required
1

Click on the area where topoisomerase would be located:

DEEPEN: Let's see how the concepts and steps behind replication get used in a real-world example of biotechnology.
Take a look at the next slide and the following video for an example of polymerase chain reaction (PCR).
Note that denaturation here is not the same thing as enzyme denaturation from your past lesson on enzymes. This one refers to how DNA is broken apart by high heat.
Required
1

Categorize each enzyme and/or PCR process according to their function in DNA replication.

  • Taq polymerase + heating to 72 degrees C
  • DNA polymerase
  • helicase
  • heating to 95 degrees C
  • primase
  • cooling to 55 degrees C
  • ligase
  • Synthesizes new DNA
  • Breaks apart DNA strands
  • Attaches primers
  • Seals DNA together after replication

EXIT:

ATTENTION:

YOU WILL USE THE ANSWERS FROM MULTIPLE CHOICE QUESTIONS 10-13.
TO ANSWER THE FOUR (4) MULTIPLE CHOICE QUESTIONS IN CANVAS IN
"B.6(A) DNA Replication Review"
Each question must be correct on Canvas to receive full credit.
Required
1

Think of all the enzymes involved in DNA replication. If ligase were to be removed from a cell, what would happen?

Required
1

Compare the DNA strands replicated in PCR to the replication fork from natural DNA replication. Why does PCR not have Okazaki fragments?

Required
1

What might cause the separate DNA strands in a replication fork to snap back together and end replication early?

Required
1

Recall that all of these enzymes and steps occur in the S phase of the cell cycle. If it weren't for DNA replication, what might happen to dividing cells during mitosis?

BEFORE YOU SUBMIT YOUR FORMATIVE: READ THIS!

YOU WILL USE THE ANSWERS FROM MULTIPLE CHOICE QUESTIONS 10-13 IN THIS FORMATIVE.
TO ANSWER THE FOUR (4) MULTIPLE CHOICE QUESTIONS IN CANVAS IN
"B.6(A) DNA Replication Review"
Each question must be correct on canvas to receive full credit.