2014 Biology Exam Predictions

[Rishi97]

is anyone willing to give a brief run down of the steps of DNA Replication?
I need help!!!

[katiesaliba]

How I hope so! 
How'd you go on it? I found it quite easy which is a scary thing knowing this year might be harder ._.

I got 105/110
Mhmm :\ I hate the population genetics questions though ahh! They just confuse me

[Tyleralp1]

is anyone willing to give a brief run down of the steps of DNA Replication?
I need help!!!

1. The DNA molecule unwinds its double helix shape and unzips by DNA helicase (an enzyme) which breaks the weak hydrogen bonds between the bases of the 2 strands. This leaves unpaired or exposed bases (A, T, C, G).
2. Free DNA nucleotides in nucleus are joined to their complementary bases on both strands of DNA. The enzyme DNA polymerase adds the complementary nucleotides.
3. Occurs in 5’ to 3’ direction only. The leading strand is built as a continuous length while the other lagging strand is built in the opposite direction in short fragments. The two strands in DNA are antiparallel.

Leading strand: Blue strand is read 3’to 5’ so the red strand is made by 5’to 3’
Lagging strand: Blue strand is read 3’ to ‘5 so the red strand is made 5 ’to 3’ but because it is in the opposite direction it is more difficult to read and short fragments are produced.

4. DNA ligase is the 3rd enzyme involved in DNA replication that joins the short fragments together (ligase is like glue, sticks nucleotides together).
5. Two double stranded molecules of DNA result, each containing one new strand and one original (old) strand. This is called semi-conservative replication as one strand is conserved or retained from one generation to the next. (One old strand and one new strand!)

[nerdmmb]

I got 105/110
Mhmm :\ I hate the population genetics questions though ahh! They just confuse me

That's a great score! You're definitely well prepared!

[katiesaliba]

is anyone willing to give a brief run down of the steps of DNA Replication?
I need help!!!

I love DNA replication ahaha so I'll give it a shot

-DNA helicase catalyses the unwinding of DNA, creating a replication bubble.
-RNA primase creates RNA primers on both strands. The lagging strand ('5-->'3) has numerous RNA primers attached and the leading strand ('3-->'5) has one.
-DNA polymerase III catalyses the synthesis of complementary DNA strands (in the '5-->'3 direction) using free deoxyribonucleotides and extending from the RNA primers. The leading strand will be continuous where as the lagging strand (due to its orientation) will be discontinuous, resulting in okazaki fragments.
-DNA polymerase I converts the RNA primers to DNA and DNA ligase joins the okazaki fragments

I got 105/110
Mhmm :\ I hate the population genetics questions though ahh! They just confuse me
[/quote

That's a great score! You're definitely well prepared!

Thanks! I hope so ahh D:

[Coralista]

1. The DNA molecule unwinds its double helix shape and unzips by DNA helicase (an enzyme) which breaks the weak hydrogen bonds between the bases of the 2 strands. This leaves unpaired or exposed bases (A, T, C, G).
2. Free DNA nucleotides in nucleus are joined to their complementary bases on both strands of DNA. The enzyme DNA polymerase adds the complementary nucleotides.
3. Occurs in 5’ to 3’ direction only. The leading strand is built as a continuous length while the other lagging strand is built in the opposite direction in short fragments. The two strands in DNA are antiparallel.

Leading strand: Blue strand is read 3’to 5’ so the red strand is made by 5’to 3’
Lagging strand: Blue strand is read 3’ to ‘5 so the red strand is made 5 ’to 3’ but because it is in the opposite direction it is more difficult to read and short fragments are produced.

4. DNA ligase is the 3rd enzyme involved in DNA replication that joins the short fragments together (ligase is like glue, sticks nucleotides together).
5. Two double stranded molecules of DNA result, each containing one new strand and one original (old) strand. This is called semi-conservative replication as one strand is conserved or retained from one generation to the next. (One old strand and one new strand!)

I Just have something to add, after step 1, RNA primase attaches to the exposed strands to initiate the process as DNA polymerases need a double-stranded DNA region to which they can attach in order to begin copying the rest of the DNA strand 

[Idolift]

I'm really feeling a question on inflammation/Hypersensitivity.

Also when you guys discuss gene technologies, Any in particular you expect tomorrow?

[doomdestroyer]

Also when you guys discuss gene technologies, Any in particular you expect tomorrow?

Gel electrophoresis.

[Reus]

Best of luck guys! Let's ace this exam, we've all worked hard and deserve it. 

[dankfrank420]

Best of luck guys! Let's ace this exam, we've all worked hard and deserve it. 

Yep.

Good luck tomorrow guys!

[katiesaliba]

Best of luck guys! Let's ace this exam, we've all worked hard and deserve it. 

May the odds be ever in our favour  haha best of luck guys!

[Tyleralp1]

Best of luck everyone!!

[anat0my]

Hope everyone smashes the exam tomorrow! Massive shout out to everyone who contributed on the threads

[Reus]

I think they might ask us to draw the monomer of a protein!!

[Rishi97]

I think they might ask us to draw the monomer of a protein!!

woah are you a wizard?