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!

Obavezno

1

Match the name of each enzyme with its function.

Stavka koja se može prevući		Odgovarajuća stavka
ligase		opens up the DNA, separating the two strands by breaking the hydrogen bonds between their bases
primase		replicates DNA molecules to make a new complementary strand
topoisomerase		lays down RNA primers which allow DNA polymerase to bind to the DNA
DNA polymerase		seals the DNA together after replication
helicase		prevents DNA ahead of the helicase from supercoiling

Obavezno

1

Match the replication terms with their definition.

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

Obavezno

1

What is the function of the enzyme exonuclease?

replicates DNA molecules to make a new complementary strand

removes RNA primers put down by primase

seals the DNA together after replication

removes DNA primers put down by ligase

Obavezno

1

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

DNA polymerase filling in the gaps after primers are removed

Helicase re-zipping the old DNA strands together

Ligase filling in the gaps between Okazaki fragments

DNA polymerase filling in the gaps after SSBs are removed

Obavezno

1

Click on the area where helicase would be located:

Obavezno

1

Click on the area where primase would be located:

Obavezno

1

Click on the area where DNA polymerase would be located:

Obavezno

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.

Obavezno

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.

Obavezno

1

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

The two DNA strands would supercoil and prevent replication.

Newly-synthesized DNA would not hold together and would break apart.

The replication fork would not form.

DNA could not be synthesized.

Obavezno

1

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

Okazaki fragments only form on a leading strand, which PCR does not have.

Okazaki fragments only form on a lagging strand, which PCR does not have.

Okazaki fragments require ligase to form, which PCR does not use.

Okazaki fragments do get formed during PCR.

Obavezno

1

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

a lack of RNA primers

denaturation of topoisomerase

failure of SSB proteins to attach to the DNA strands

exonuclease becoming unattached from the RNA primers

Obavezno

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?

The sister chromatids would not separate correctly during anaphase.

There would be too much DNA given to the daughter cell.

The chromosomes would not line up properly during metaphase.

Nothing; without DNA replication the cell would not be allowed to proceed to mitosis at all due to the G2 checkpoint.

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.

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

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

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

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

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

Match the name of each enzyme with its function.

Match the replication terms with their definition.

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

What is the function of the enzyme exonuclease?

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

Click on the area where helicase would be located:

Click on the area where primase would be located:

Click on the area where DNA polymerase would be located:

Click on the area where topoisomerase would be located:

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

EXIT:

ATTENTION:

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

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

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

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!

Match the name of each enzyme with its function.

Match the replication terms with their definition.

What is the function of the enzyme exonuclease?

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

Click on the area where helicase would be located:

Click on the area where primase would be located:

Click on the area where DNA polymerase would be located:

Click on the area where topoisomerase would be located:

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

EXIT:

ATTENTION:

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

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

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

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!