AS Biology paper 22 May 13th 2013

[songjihyo]

you guys, you know tht question about how smoking increases the risk of TB? i wrote that Nicotine causes blood platelets to be sticky, and so it reduces the blood vessels, less nutrients and oxygen will be carried to the immune cells, therefore this weakens the immune system, and TB is an opportunistic disease.. Hence it increases the risk of TB. Does this make any sense? :/

 

[h4rriet]

you guys, you know tht question about how smoking increases the risk of TB? i wrote that Nicotine causes blood platelets to be sticky, and so it reduces the blood vessels, less nutrients and oxygen will be carried to the immune cells, therefore this weakens the immune system, and TB is an opportunistic disease.. Hence it increases the risk of TB. Does this make any sense? :/

Yes, it does.

 

[Eng Minhal]

Do you know good biology teachers in karachi?

 

[shah zaib]

can anyone tell the correct disacchrides that we had to find out from A to D ?
plus what is the expected gt ? i think it would be 40 +/- 2.

 

[Jinkglex]

Yes, it does.

Im sorry but im pretty sure your disachirides are incorrect.

The order was Cellobiose first and trehalose last, and im unsure which of the middle ones was sucrose, but it was the one without the criss-crossing glycosidic bond.

EDIT: cellobiose was indeed C not A....thats wierd....

EDIT 2: Google is showing the structures of maltose and sucrose to be the same :?

 

[jerray]

Im sorry but im pretty sure your disachirides are incorrect.

The order was Cellobiose first and trehalose last, and im unsure which of the middle ones was sucrose, but it was the one without the criss-crossing glycosidic bond.

EDIT: cellobiose was indeed C not A....thats wierd....

EDIT 2: Google is showing the structures of maltose and sucrose to be the same :?

not so.
sucrose had a pentose ring structure, along with a hexose.
maltose has two hexose rings.

 

[terry jefferson]

Im sorry but im pretty sure your disachirides are incorrect.

The order was Cellobiose first and trehalose last, and im unsure which of the middle ones was sucrose, but it was the one without the criss-crossing glycosidic bond.

EDIT: cellobiose was indeed C not A....thats wierd....

EDIT 2: Google is showing the structures of maltose and sucrose to be the same :?

A-sucrose B-trehalose C-cellubiose D-maltose

 

[tanixx]

not so.
sucrose had a pentose ring structure, along with a hexose.
maltose has two hexose rings.

so trehalose was A or B?

 

[songjihyo]

Yes, it does.

aaaa Thanks youuu!

 

[tanixx]

A-sucrose B-trehalose C-cellubiose D-maltose

sucrose was D

 

[rabos1]

Leave maltose wala question... Most of the ppl wrote different answers..

 

[Moi]

1- For the disaccharides...i got
A-Cellobaise (wtvr the name is) ---> two beta glucose
B-Maltose --->Two Alpha Glucose
C-Trehalos (or sucrose)
D- Sucrose (or Trehalos)

2-What is the actual size in the magnification question?
i got it 5 !!

3-why canser cells have extra mitochondrea and RER?
i made up my answer saying that it needed mauch energy for reproduction and protien synthesis to spread out (Things along the line)

Someone Correct me!

 

[Moi]

GUYS HERE IS THE CORRECT DISACCHARIDE NAMINGS !

A-Trehalose B- Maltose C-Cellobois D-Sucrose


My mistake was A And C.......dang

 

[rabos1]

1- For the disaccharides...i got
A-Cellobaise (wtvr the name is) ---> two beta glucose
B-Maltose --->Two Alpha Glucose
C-Trehalos (or sucrose)
D- Sucrose (or Trehalos)

2-What is the actual size in the magnification question?
i got it 5 !!

3-why canser cells have extra mitochondrea and RER?
i made up my answer saying that it needed mauch energy for reproduction and protien synthesis to spread out (Things along the line)

Someone Correct me!

I think it was 13.

I don't remember.. your measurement and then convert it to micrometers.. and then we were supposed to divide it by magnification given.. this is what you did?

I wrote for cancerous cells, uncontrolled cell division takes place so we need more mitochondria to provide atp and rer for modifiation of proteins and blah blah.

 

[Moi]

I think it was 13.

I don't remember.. your measurement and then convert it to micrometers.. and then we were supposed to divide it by magnification given.. this is what you did?

I wrote for cancerous cells, uncontrolled cell division takes place so we need more mitochondria to provide atp and ret for modification of oroteins and blah blah.

OMG ...i just realised i used inches ruler not cm ruler....omg how many marks did it have???

 

[rabos1]

3 I think. Yaar I made HUGE blunders. I hope percentile low ho... inches? Did you convert it to micrometers?

 

[shah zaib]

1- For the disaccharides...i got
A-Cellobaise (wtvr the name is) ---> two beta glucose
B-Maltose --->Two Alpha Glucose
C-Trehalos (or sucrose)
D- Sucrose (or Trehalos)

2-What is the actual size in the magnification question?
i got it 5 !!

3-why canser cells have extra mitochondrea and RER?
i made up my answer saying that it needed mauch energy for reproduction and protien synthesis to spread out (Things along the line)

Someone Correct me!

trehalose was two alpha glucose as well. wasn't it ?

 

[rabos1]

You will get some marks if you divided your measurement with magnification.

 

[Rommarrooo]

That actually has more logic to it than anything I came up with. Good job

you guys, you know tht question about how smoking increases the risk of TB? i wrote that Nicotine causes blood platelets to be sticky, and so it reduces the blood vessels, less nutrients and oxygen will be carried to the immune cells, therefore this weakens the immune system, and TB is an opportunistic disease.. Hence it increases the risk of TB. Does this make any sense? :/

 

[Moi]

3 I think. Yaar I made HUGE blunders. I hope percentile low ho... inches? Did you convert it to micrometers?

i converted my measurment from cm to micrometers when infact i didnt realize i measured by inches not cm!!