AQA BIOL1 Biology Unit 1 Exam - 16th May 2011

Original post by Sparkly-Star

What you guys doing? I keep forgetting everything. :frown:

I need to keep going over all my notes. :frown:

Same!!
I'm so frigging stressed :'(

Reply 304

Original post by EffKayy

Livia!!!

I'm so stressed urgh... I feel like i don't know anything.

You'll be fine!

Reply 305

Original post by TlanTlan

Incorrect, sodium is pumped into the lumen of the intestine so that glucose can be absorbed through the sodium-glucose co-transporter protein. Which uses sodium travelling down its concentration gradient to move glucose moving against its concentration gradient through a co-transporter carrier protein.

NO!
She's correct
Sodium ions get actively transported into the BLOOD, thereby leaving the lumen of the intestine with a higher concentration of sodium ions.

Reply 306

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8

Original post by TlanTlan

Incorrect, sodium is pumped into the lumen of the intestine so that glucose can be absorbed through the sodium-glucose co-transporter protein. Which uses sodium travelling down its concentration gradient to move glucose moving against its concentration gradient through a co-transporter carrier protein.

Can we use this instead of saying incorrect

Cos it's more fun :biggrin:

Oh and do you need to mention when the glucose enters the epithelium the concentration of it increases so enters the blood as the blood has lower concentration?

Reply 307

TlanTlan

6

How are the lungs adapted to their function, and describe the symptoms and effects of emphysema, fibrosis, and asthma on the lungs.

It's a very big question but i'm sure lungs will come up :biggrin:

Reply 308

Original post by TlanTlan

Incorrect, sodium is pumped into the lumen of the intestine so that glucose can be absorbed through the sodium-glucose co-transporter protein. Which uses sodium travelling down its concentration gradient to move glucose moving against its concentration gradient through a co-transporter carrier protein.

No, that's not right. It goes into the blood. Look at June 09, question 7b.

Reply 309

Original post by EffKayy

NO!
She's correct
Sodium ions get actively transported into the BLOOD, thereby leaving the lumen of the intestine with a higher concentration of sodium ions.

Thanks

Reply 310

TlanTlan

6

Original post by EffKayy

NO!
She's correct
Sodium ions get actively transported into the BLOOD, thereby leaving the lumen of the intestine with a higher concentration of sodium ions.

:O , i thought i knew this! Oh crap, time to go over that quick. Stress is also getting to me now!

Reply 311

Original post by TlanTlan

:O , i thought i knew this! Oh crap, time to go over that quick. Stress is also getting to me now!

Don't worry! I'm stressing out too, i kinda ish forgot what an SEM does !!!!!!! :|

Reply 312

swiftylol

18

I haaattteeeeee this unit the only thing interesting is immunity the rest is boooooooooorring : (

Reply 313

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8

Original post by TlanTlan

How are the lungs adapted to their function, and describe the symptoms and effects of emphysema, fibrosis, and asthma on the lungs.

It's a very big question but i'm sure lungs will come up :biggrin:

Diaphram pushes down and moves down when inhalation occurs to lungs have bigger space so pressure decreases which allows air in and the coverse of that too. They have avelus that increase surface area so faster diffusion. They are also small so small diffusion path way.
Emphysema is caused by smoking and the elastin is stretched so less oxygen can be ventilated. Less diffusion as concentration gradient is lower. Symptons. Lack of air. Cough.

Fibrosis is scar tissues forming so less elastic tissue. Thicker walls less diffusion. Shortness of breath, chest pains and dry coughs.

Astma is a allergic reaction to dust and dirt. Causes a reaction so the air way closes up so less oxygen in so less concentration gradient. More mucas produced so covers aveolus so less surface area.

I think.

Reply 314

Original post by TlanTlan

How are the lungs adapted to their function, and describe the symptoms and effects of emphysema, fibrosis, and asthma on the lungs.

It's a very big question but i'm sure lungs will come up :biggrin:

Okaayyy..

Adaped to their function:
-Many alveloi - large surface area, greater rate of diffusion
-Many cappilaries - ^
-Thin wall of alveoli/cappilaries - short diffusion pathway
-Ventilation / circulation - large conc. grad

Emphysema - alveloi break down, and walls thinken - less s.area and longer diffusion pathway. Loss of elastin by elastase, can't recoil, reducded conc gradient. Less oxygen to tissues.

Fibrosis - scar tissue due to asbestos etc, longer diffusion pathway. Twisted alveoli - less s.area. Hence lower conc gradient, so shortness of breath and coughing.

Asthma - smooth muscle contracts, narrows lumen, more mucus from epithelial cells. Breathing rate increased, but tidal vol reducded. Wheezing, quick shallow breaths.

Phew!

Reply 315

PanicPanicPanicPanic!!!!!!!!!! I THOUGHT I KNEW MOST OF THE STUFF! I DON'T!!!!! :frown:

Reply 316

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8

Original post by EffKayy

PanicPanicPanicPanic!!!!!!!!!! I THOUGHT I KNEW MOST OF THE STUFF! I DON'T!!!!! :frown:

Takes deep breaths. Irony since lungs are being discussed :tongue:

Reply 317

Just read through the thread. Very helpful :smile:

but I'm surprised by how much info some people are putting. I'm just a CGP type of girl... got me through Gcses so fingers crossed :tongue:

Question a while back on why the secondary response is stronger and quicker... i learnt it was about affinity maturation (as well as more memory cells) ... anybody else learnt this?

Reply 318