Biology Exam: Answers and Discussion!

[anat0my]

Hey what did you guys write for the facilitated diffusion question? I feel like some of the questions were broad and ambiguous.

[Coralista]

What SS Am i looking at if i get a low A+ with A+ sacs and rank 1?

probably 39+ but it depends on numerous factors such as overall cohort strength etc..

Can anyone explain question 12 of MC?

For question 12, option A cannot be correct as most of the ATP is made in electron transport, option B is incorrect as pyruvic acid is converted to acetyl CoA under aerobic conditions, option C is also incorrect as the breakdown of glucose under anaerobic conditions will result in 2 ATP. Leaving us with option D, its correct as fat and lipids are able to store more energy due to their lack of affinity for water molecules

[Reus]

Z^R Z^r X Z^r W

ceebs typing it out, but thats the cross i did

Thank God! At first I did Rr x rr but then changed it haha. I think I went with Z^R Z^R X Z^r W though...

Hey what did you guys write for the facilitated diffusion question? I feel like some of the questions were broad and ambiguous.

I just said the accumulation of glucose inside the cell is high concentrated so through facilitated diffusion it wants to rebalances the low levels of glucose outside hence diffuses (high to low concentration gradient) I had to retain this memory from units 1 and 2 tbh.

[Aman476]

Crap, as if pyruvic acid can be used exactly the same way as the ion (pyruvate), thought it was some other path haha so didnt see any O2 so i chose B damn! 38/40

That question 20 got me ahaah

[katiesaliba]

Z^R Z^r X Z^r W

ceebs typing it out, but thats the cross i did

Same!

[Reus]

Crap, as if pyruvic acid can be used exactly the same way as the ion (pyruvate), thought it was some other path haha so didnt see any O2 so i chose B damn! 38/40

That question 20 got me ahaah

Better than my 35 ._.

[Aman476]

Did everyone say carrier protein for glucose (talk about conformation change?) and moving from high conc to low con? (with concentration gradient) for that question?? I nearly said through a protein channel but got lucky in remembering that its carrier for glucose and channel for ions and such (smaller).

[Aman476]

Better than my 35 ._.

haha well done man, i reckon high 40's are still probable if we don't lose more than 7-9 marks, since this exam was more on par with the old u3 and u4 exams (a+ was over 76% a lot of the time) last years was i think a little easier (hence the higher a+ cut off 85) so we should do well if we get 101-103 out of 110 (92-94%) 

[Vicbelgaus]

Did everyone say carrier protein for glucose (talk about conformation change?) and moving from high conc to low con? (with concentration gradient) for that question?? I nearly said through a protein channel but got lucky in remembering that its carrier for glucose and channel for ions and such (smaller).

Fak i said protein channel -_-


oh dear this isn't looking so good anymore

[yvyngu]

Guys I did 3 x 90 = 210 I'm so angry kicking myself in the head

[katiesaliba]

Fak i said protein channel -_-


oh dear this isn't looking so good anymore

To be honest, I reckon they would accept either protein channels or carrier proteins. Maybe not though, dunno.

[Aman476]

I don't get why 270 is wrong, if you were to count the start and stop codons (bases that  code for a acids  which aren't actually part of the polymer) then why stop there? Why exclude the promoter sequence, and the other bases that get added to it (adenine tail, methylated cap?) I reckon it was 270, only because it used the word 'coding'.

"Stop codons signal the termination of this process by binding release factors, which cause the ribosomal subunits to disassociate, releasing the amino acid chain. While start codons need nearby sequences or initiation factors to start translation, stop codon alone is sufficient to initiate termination." - wiki

Stop and Start aren't translated 

[Vicbelgaus]

I don't get why 270 is wrong, if you were to count the start and stop codons (bases that  code for a acids  which aren't actually part of the polymer) then why stop there? Why exclude the promoter sequence, and the other bases that get added to it (adenine tail, methylated cap?) I reckon it was 270, only because it used the word 'coding'.

"Stop codons signal the termination of this process by binding release factors, which cause the ribosomal subunits to disassociate, releasing the amino acid chain. While start codons need nearby sequences or initiation factors to start translation, stop codon alone is sufficient to initiate termination." - wiki

Stop and Start aren't translated 

that is the same conclusion i came to in regards to that question.

[Vicbelgaus]

To be honest, I reckon they would accept either protein channels or carrier proteins. Maybe not though, dunno.

i hope you are right there  ,really need to get all the marks i can get in short answer since i dropped 3 in multiple choice

[dankfrank420]

For the glucose question, I said something like

glucose is unable to pass directly through the phospholipid bilayer, so it must pass through the membrane through specific protein channels embedded in the membrane.This process does not require energy.

I don't get why 270 is wrong, if you were to count the start and stop codons (bases that  code for a acids  which aren't actually part of the polymer) then why stop there? Why exclude the promoter sequence, and the other bases that get added to it (adenine tail, methylated cap?) I reckon it was 270, only because it used the word 'coding'.

"Stop codons signal the termination of this process by binding release factors, which cause the ribosomal subunits to disassociate, releasing the amino acid chain. While start codons need nearby sequences or initiation factors to start translation, stop codon alone is sufficient to initiate termination." - wiki

Stop and Start aren't translated 

I wrote:

90 amino acids, and 3 nucleotides per amino acid hence 90*3=270
However, add 3 nucleotides for STOP codon
Therefore 270+3=273 bases needed