AS LEVEL BIOLOGY... discuss here AS students only :)

[HubbaBubba]

Does catalase have haem group? so confused

No, only haemoglobin contains haem group as far as AS biology is concerned

 

[Bebeskii]

No, only haemoglobin contains haem group as far as AS biology is concerned

okay TOMORROW EXAM

 

[Bebeskii]

I'm nervous about my exam. Do you think there will be a question about heart and blood vessels?

 

[daredevil]

I'm nervous about my exam. Do you think there will be a question about heart and blood vessels?

i wish... because that is like the SINGLE most decent chap of the whole book _-_ that keeps bio running for me otherwise its all a load of crap -__- x.x

 

[HubbaBubba]

i wish... because that is like the SINGLE most decent chap of the whole book _-_ that keeps bio running for me otherwise its all a load of crap -__- x.x

I hope they bring a lot of gas exchange/smoking parts and infectious diseases. They are so easy, you get free marks. I really hope they don't bring Bohr effect or haemoglobin. I suck so much at it. It's the thing that brought my grade down in May/June 2012 session haha

 

[Bebeskii]

i wish... because that is like the SINGLE most decent chap of the whole book _-_ that keeps bio running for me otherwise its all a load of crap -__- x.x

questions about heart is very hard for me.

 

[Bebeskii]

I hope they bring a lot of gas exchange/smoking parts and infectious diseases. They are so easy, you get free marks. I really hope they don't bring Bohr effect or haemoglobin. I suck so much at it. It's the thing that brought my grade down in May/June 2012 session haha

yeah i agree. I find translocation, transcription and translation hard

 

[Bebeskii]

Is narrow lumen advantage or disadvantage for xylem vessel? i thought narrow lumen increases the contact of water with wall, so water adhere to the wall. However, in the past paper question it was advantage, saying more amount of water can be moved along by mass flow. ?!

 

[HubbaBubba]

Is narrow lumen advantage or disadvantage for xylem vessel? i thought narrow lumen increases the contact of water with wall, so water adhere to the wall. However, in the past paper question it was advantage, saying more amount of water can be moved along by mass flow. ?!

It is an advantage, because water molecules are adhesive and cohesive. By decreasing lumen of the xylem the molecules are more able to stick to walls of xylem. When there's a transpiration pull, water molecules pull each other up by mass flow making a continuous flow

 

[Bebeskii]

It is an advantage, because water molecules are adhesive and cohesive. By decreasing lumen of the xylem the molecules are more able to stick to walls of xylem. When there's a transpiration pull, water molecules pull each other up by mass flow making a continuous flow

thanks. It seems you are gonna get A.

 

[Gimmick]

No, only haemoglobin contains haem group as far as AS biology is concerned

There have been some questions regarding catalase, but they mention that catalase ALSO has a haem goup (4, I think).

 

[HubbaBubba]

There have been some questions regarding catalase, but they mention that catalase ALSO has a haem goup (4, I think).

Even if it is mentioned, it's not required for us to know that. CIE AS Biology Syllabus says that we only need to know structure of haemoglobin for globular proteins, and fibrogen for fibrous protein. I guess catalase might have a haem group but I wouldn't know, as I haven't studied it :/

 

[Irfan1995]

Does catalase have haem group? so confused

From what I know, catalase DOES have a haem group. A haem group is just a group that contains iron. In RBCs, the haem group binds to oxygen, but in catalase, the haem group binds to hydrogen peroxide.

EDIT: this is what I know from AP Biology; I'm not sure if it's included in the AS syllabus.

 

[HubbaBubba]

thanks. It seems you are gonna get A.

Inshallah! I studied very hard this year. I don't want to do the same mistakes I did last year :/

 

[daredevil]

Is narrow lumen advantage or disadvantage for xylem vessel? i thought narrow lumen increases the contact of water with wall, so water adhere to the wall. However, in the past paper question it was advantage, saying more amount of water can be moved along by mass flow. ?!

adding to what HubbaBubba already said... it actually helps in transport of water by capillary action. that needs a narrow lumen so it helps

 

[ruler_of_the_world]

In one paper they asked us for the structure n explanation of xylem so they had mentioned large diameter so more water can pass....
Wat r we supposed to write!

 

[daredevil]

In one paper they asked us for the structure n explanation of xylem so they had mentioned large diameter so more water can pass....
Wat r we supposed to write!

no i think the adaptation for more water to pass is that there is no cytoplasm or anything in the xylem [its hollow]. the lumen is narrow for the capillary action... i think thats the way it goes

 

[ruler_of_the_world]

K but I jus hope there aren't any twisting qs this year :S

 

[daredevil]

K but I jus hope there aren't any twisting qs this year :S

yeah.... i wish for smooth sailing... like in the previous papers of maths chem and phy that wud be rad!!

 

[ruler_of_the_world]

Yea man easy papers along with extreme low thresholds!