LECTURE 3 Flashcards
According to the video What Happens When Your DNA Is Damaged, what can be a rad result of a lot of damage done to your DNA?
Cancer
According to the video What Happens When Your DNA Is Damaged, one common error is base mismatches. What takes place during this error?
Apoptosis
According to the video What Happens When Your DNA Is Damaged, one common error is base mismatches. How does mismatch repair occur to fix these problems?
Mismatch repair occurs by proteins checking the work of the enzymes and if they find any errors they essentially cut out the incorrect nucleotide and replace it.
According to the video What Happens When Your DNA Is Damaged, how can DNA get damaged after DNA replication?
DNA can get damaged after DNA replication by different compound chemicals interfering with your molecules.
According to the video What Happens When Your DNA Is Damaged, if only one nucleotide is damaged after DNA replication, what type of repair can take place to fix the problem and how is it done?
The type is: Base Excision Repair
How it’s done: One enzyme snips out the damaged base and other enzymes come in to trim around the site and replace the nucleotides.
According to the video What Happens When Your DNA Is Damaged, how can UV light damage DNA?
UV light can damage DNA by causing the two adjacent nucleotides to stick together which basically distorts the DNA’s double helix shape.
According to the video What Happens When Your DNA Is Damaged, how does nucleotide excision repair fix damaged DNA?
A team of proteins removes a long strand of about 24 nucleotides and replaces them with new ones.
According to the video What Happens When Your DNA Is Damaged, why are double strand breaks the most dangerous?
Even just one can lead to cell death.
According to the video What Happens When Your DNA Is Damaged, what are the names of the two types of repair that can fix double-strand breaks in the DNA backbone?
- Homologous Recombination
- Non-Homologous End Joining
According to the video What Happens When Your DNA Is Damaged, there are two types of repair that can fix double-strand breaks in the DNA backbone. How does each type fix these kinds of breaks?
- Homologous Recombination: Uses an undamaged section of similar DNA as a template, enzymes then interlace the damaged and undamaged strands, get them to exchange sequences of nucleotides, and then finally fill in any missing gaps. The end product is two complete double-stranded segments.
- Non-Homologous End Joining: A series of proteins trims off a few nucleotides and then fuses together the broken ends (this way isn’t as accurate).
Our bodies have many different specific DNA repairs systems. Which statement describes the UVR photorepair system?
Corrects the thymine dimers that form, and corrects damage caused by UV light. It is a specific mechanism to correct DNA errors caused by radiation.
Our bodies have many different specific DNA repairs systems. Which statement describes the Apyrimidinic (AP) site repair?
Fixes instances where uracil is present in DNA because it should only be present in RNA. It will replace it with thymine.
Which statement is true regarding excision repairs? (know what they are, what they can fix, and how they are used)
When DNA replication and chemical damage is there, it will repair a wide variety of lesions to the DNA. Remove what doesn’t belong, repair polymerase and fill in the resulting gaps with a new sequence.
_____________ repair is the only repair system able to handle double-strand breaks in DNA and can be found within eukaryotes. Fill in the blank.
Post
Recombinational repair can occur within which phases of meiosis or mitosis within eukaryotes?
Meiosis I prophase.
