Replication

Question 1

What are the 4 base pairs

Answer 1

thymine, cytosine, guanine, adenine

Question 2

what does thymine turn into

Answer 2

uracil

Question 3

which base pairs are purines

Answer 3

guanine and adnine

Question 4

which base pairs are pyramidines

Answer 4

Cytosine, Uracil, and thymine

Question 5

what is the semi-conservative model

Answer 5

where there is a single parental DNA strand that when added to another splits into two and adds the secondary strand,

Question 6

what is the conservative model

Answer 6

where the parental strand will always keep its colour and not mix with the other strand.

Question 7

What did Franklin Stahl do?

Answer 7

he found out whether it was semi-conservative or conservative by adding nitrogen to a petri dish and watched as it divided.

Question 8

what is continuous replication?

Answer 8

This is the continuous breaking of bonds between the backbones, the continuous replication determines whether or not there would need to be extra RNA primers along the way, continuous means that it does not stop and this will always go from 5’ to 3’ and will just continuously elongate without stopping.

Question 9

what is discontinuous replication?

Answer 9

This implies that while going from 5’ to 3’ because it needs to be antiparallel the RNA primer will reach the end and have to replace itself to continue going along, this phenomenon is called Okazaki fragments, these are the fragments that are short pieces along the way on the 3’ to 5’ backbone.

Question 10

which proteins are used during discontinuous replication

Answer 10

RNA primase
polymerase
ligase
topoisomerase
helicase
single-stranded binding proteins

Question 11

how is replication sped up?

Answer 11

by dividing in different places causing replication bubbles.

Question 12

what is the difference in size between the leading and lagging strands? and why does that happen?

Answer 12

the lagging is shorter by ~100 nucleotides, this is caused by the final primer removed at the end

Question 13

how is the lagging difference fixed in the end?

Answer 13

telomeres cap the end with a TTAGGG repeated sequence that gets shorter each time

Question 14

what happens after 50 divisions of a germ cell and stem cell?

Answer 14

these will begin to be less youthful and heal cuts and injuries slower caused by the shortened TTAGGG sequence.

Question 15

What do DNA polymerase do to prevent mistakes?

Answer 15

they proofread each code.

Question 16

what is the terminator of a template (sanger) strand?

Answer 16

it ends with a dideoxynucleotide at the 3’ end.