KAA-Lecture 3- DNA Replication 8_14.pdf Flashcards
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KAA-Lecture 3- DNA Replication 8_14.pdf Flashcards
KAA-Lecture 3- DNA Replication 8_14.pdf Flashcards
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What occurs during the S phase of mitosis?
DNA replication occurs during the S phase of mitosis.
Why do cells divide?
Cells divide for many reasons, for example, to replace old, dead, or damaged cells.
What are examples of cells with short lifespans?
Examples of cells with short lifespans include skin cells and blood cells.
What is one reason cells divide in living organisms?
Cells divide so living things can grow.
What happens when an organism grows in terms of cell size and number?
When an organism grows, the cells themselves are not getting larger; rather, cells are dividing to produce more and more cells.
What is the average lifespan of erythrocytes (red blood cells)?
The average lifespan of erythrocytes (red blood cells) is 120 days.
What is the average lifespan of white blood cells (WBCs)?
The average lifespan of white blood cells (WBCs) is 5 to 21 days.
What triggers an increase in the number of white blood cells?
The number of WBCs increases in response to infection.
What is the semi-conservative DNA replication model?
In the semi-conservative DNA replication model, the two strands of DNA unwind from each other and each acts as a template for synthesis of a new complementary strand.
What does DNA replication produce?
DNA replication produces two complete double helices from the original DNA molecule.
How does each resulting DNA helix compare to the parental DNA?
Each resulting DNA helix is identical in nucleotide sequence to the parental DNA.
What are the steps in DNA replication?
The steps in DNA replication are Initiation, Elongation, and Termination.
What is a replication fork?
A replication fork is the area where the double-stranded DNA molecule is unzipped into two single strands.
What enzyme is responsible for unwinding DNA during replication?
DNA helicase is the enzyme responsible for unwinding DNA during replication.
What is the origin of replication?
The origin of replication is a particular sequence of DNA at which replication is initiated, typically composed of an AT-rich sequence.
How does DNA helicase function during DNA replication?
DNA helicase disrupts the hydrogen bonding between base pairs to separate the strands into a Y shape known as the replication fork.
What direction do DNA polymerases add nucleotides?
DNA polymerases can only add nucleotides to the 3' end.
How do leading and lagging strands differ in DNA replication?
The leading strand's DNA polymerase moves along the 3' to 5' strand assembling the new strand in the 5' to 3' direction, while the lagging strand's polymerase replicates it in short segments called Okazaki fragments.
What are Okazaki fragments?
Okazaki fragments are short segments that make up the lagging strand during DNA replication.
Who won the Nobel Prize in Chemistry in 1993 for work related to PCR?
Kary Mullis won the Nobel Prize in Chemistry in 1993.
What applications has PCR revolutionized in molecular biology?
PCR has revolutionized molecular biology by enabling the ability to make millions of copies of specific sequences.
What are some applications of PCR in genetic testing?
Applications of PCR in genetic testing include mapping of genomes, tissue typing for organ transplants, oncogene testing, and diagnosis of cancer.
What does the term 'in vitro' refer to in the context of PCR?
In vitro refers to processes that occur in a controlled laboratory environment, such as a test tube.
What does 'in vivo' mean?
In vivo is Latin for 'within the living'.
What is the monomeric subunit of DNA?
The monomeric subunit of DNA is a nucleotide.
What are the four bases found in DNA?
The four bases found in DNA are adenine (A), thymine (T), guanine (G), and cytosine (C).
What was used in early PCR that was not thermostable?
Early PCR used Klenow fragment or T4 DNA polymerase, which were not thermostable.
What is Taq polymerase and where does it come from?
Taq polymerase is an enzyme that can withstand high temperatures required for PCR, named after the thermophilic bacterium Thermus aquaticus.
What is the error rate of Taq polymerase?
The error rate of Taq polymerase is approximately 1 in 9,000 nucleotides.
What is the role of the PCR buffer, specifically MgCl2?
The PCR buffer, including MgCl2, is essential for the reaction conditions in PCR.