Biology AQA AS Unit 1 June 2014

Original post by tammy:)

can we have a brainstorm on unit 1? keywords and all- anything we ve learnt that we wish to share? I think it would be a good idea and anyone with any misconceptions on any topic in unit 1 can clear it here

Lets start with Glucose co -transport because I hate that one the most and I bet il have loads of points where people will correct me

1) Na+ k+ pump has carrier channels embedded in membrane of epithelial cells linging small intestine.The conc gradient of Na+ is used to power the diffusion of Glucose INTO the cell

Somone do the point 2, then another person point 3

Whilst I jst go check ma books!

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Reply 47

DCMed96

16

Original post by tammy:)

can we have a brainstorm on unit 1? keywords and all- anything we ve learnt that we wish to share? I think it would be a good idea and anyone with any misconceptions on any topic in unit 1 can clear it here

ya sure. i am confused on the different lung diseases!!

Reply 48

Original post by TSRuserrr9

Lets start with Glucose co -transport because I hate that one the most and I bet il have loads of points where people will correct me

1) Na+ k+ pump has carrier channels embedded in membrane of epithelial cells linging small intestine.The conc gradient of Na+ is used to power the diffusion of Glucose INTO the cell

Somone do the point 2, then another person point 3

Whilst I jst go check ma books!

Posted from TSR Mobile

Why does it not surprise me-lol i think we

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Reply 49

Original post by tammy:)

Why does it not surprise me-lol i think we

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Stupid phone-.-
Lol as i was saying-i think we all hate that topic

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Reply 50

~amethyst~

4

How's everyone's revision going? There's so much to get through but so little time :eek:

....

But yeah think i need to practice some 5 markers, so anyone have any ideas on what topics may come up? Then we can type up some model answers and learn off the key points. :biggrin:

Reply 51

Original post by tammy:)

Stupid phone-.-
Lol as i was saying-i think we all hate that topic

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Damn!that means no one is gonna add any points to it..

Ok how about we all go through the Heart and Lung diseases :

Aneurysm:
WHAT? Baloon like swelling underneath endothelium layer of coronary artery
EFFECT: May burst and cause a loss of blood to region where the blood was initially intended to reach.e.g cardiac muscle cells, consequently leads to myo cardial infarction due to lack of o2 for rapidlt aeorobically respiting cells..

*just at the top of my head,someone correct me if im abit wrong*

Now some one do the same for:

Atheroma:
WHAT:
Effect:

Thrombosis:
What:
Effect:

Emphysema:
What:
Effecr:

Pulomonary TB:
What:
Effect:

COME ONNN GUYS NOT LONG TO GO NOW !!!
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Reply 52

Revisionbug

1

Hey guys how far is everyone into this unit and which chapters are your favorite and worst. Im on Lungs and Disease right now and its my favourite topic so far. How is everyone revising for it? atm I'm just doing notes from the book and going over them alot and just doing the exam qs at the end of the chapters and using a seperate book just to master the possible big questions and rewrite them according to the markscheme later. Also are there any other resources that I could use before starting past papers as soon as I finish the sixth chapter?.

Reply 53

Original post by TSRuserrr9

Damn!that means no one is gonna add any points to it..

Ok how about we all go through the Heart and Lung diseases :

Aneurysm:
WHAT? Baloon like swelling underneath endothelium layer of coronary artery
EFFECT: May burst and cause a loss of blood to region where the blood was initially intended to reach.e.g cardiac muscle cells, consequently leads to myo cardial infarction due to lack of o2 for rapidlt aeorobically respiting cells..

*just at the top of my head,someone correct me if im abit wrong*

Now some one do the same for:

Atheroma:
WHAT:
Effect:

Thrombosis:
What:
Effect:

Emphysema:
What:
Effecr:

Pulomonary TB:
What:
Effect:

COME ONNN GUYS NOT LONG TO GO NOW !!!
Posted from TSR Mobile

Emphysema:

What: a lung disease caused by smoking or long term exposure to air pollution-I.e. foreign particles getting trapped in the alveoli.in turn, causing inflammation (immune response kicks in) which attracts phagocytes to the area. Phagocytes produce an enzyme that breaks down elastin (which is a protein found in the walls of alveoli)-elastin plays a significant role in returning the alveoli back to its original shape, so without elastin the alveoli cannot recoil back to its original shape i.e. traps air inside it

Effect:
1)leads to the destruction of the alveoli walls
-> reducing S.A. of the alveoli->in turn, reducing the rate of gas exchange

2)shortness of breath- people with emphysema will have an increased breathing rate(because they'd find it difficult to increase the volume of air reaching their lungs)

(you forgot asthma and fibrosis- so lets just take it from lungs first then we can move on to the heart)
Asthma:

What: Asthma basically occurs when the airways(i.e. trachea) become inflamed/irritated.(analogy: think of it this way- if you keep on scratching the same spot over and over-your skin will obv become irritated BECAUSE of the scratching- so something is having to CAUSE the trachea to become inflamed)

Why? There are loads of causes however, its usually because of an allergic reaction to substances such as pollen and dust.

This causes the trachea to constrict -making it difficult to breathe. THE AIRFLOW-IN AND OUT OF THE LUNGS IS GREATLY REDUCED -> so, less oxygen enters alveoli and moves into the blood

Effect:
Wheezing-bc of a tight chest and shortness of breath

How can we reduce the likelihood of this occurring?
They can be relieved by drugs which cause the muscles in the bronchioles to RELAX->opening up airways

Fibrosis:
What:
OKAY. so fibrosis is the formation of scar tissue in the lungs. Scar tissue is THICKER and LESS ELASTIC than normal lung tissue.(if you know this, then it wont be hard stating the likely implications)

Causes: exposure to substances like ABESTOS or DUST

lungs are less able to expand->cant hold as much air->TIDAL VOLUME IS DECREASED->also harder to force air out of the lungs because there is no elasticity.

reduction in rate of gaseous exchange->diffusion is slower across a THICKER SCARRED MEMBRANE (make links between Fick's law-what does it state?)

Effect: 1)shortness of breath
2)dry cough
3)chest pain
4)fatigue & weakness

This would also mean that fibrosis patients will BREATHE FASTER than normal-to get enough air into their lungs to oxygenate their blood.

Pulmonary TB:
What: FIRST OF ALL GUYS, TB IS A LUNG DISEASE!

causes: It is caused by 2 different bacteria:
1)Mycobacterium TB
2)Mycobacterium Bovis

Infection: when someone becomes infected- the immune system builds a cell wall around the bacteria in the lungs. This forms SMALL HARD LUMPS aka TUBERCLES.

Infected tissue within the tubercles die->the gas exchange surface is damaged-> TIDAL VOLUME IS DECREASED

TB CAN POTENTIALLY LEAD TO FIBROSIS->further reducing the tidal volume.

This means that if bacteria enters the bloodstream-it can spread to other parts of the body

Effects: 1) persistent cough/coughing up the RED STUFF :yikes:

-> BLOOD #dontjudge #lamejokes xD
2)Shortness of breath
3)Fever
4)Lose weight
Transmission: It is an airborne disease-so coughing /sneezing/tiny droplets of saliva/mucus-all containing bacteria from infected person

How to reduce likelihood of contracting disease?
There is this vaccine called BCG VACCINE and can be treated with antibiotics over a course of time.

Many ppl are ASYMPTOMATIC to this disease-i.e. they infected but wont show any extreme symptoms. This is because the infection is in an INACTIVE FORM->but can awake from its long wait when the infected persons immune system is weakened by another disease or malnutrition (Analogy: think of it like this->a tiger waiting patiently for the right moment-and will only attack when it is 100% sure that it has got its victim where it wants it-at its most vulnerable moment)

Reply 54

Original post by Revisionbug

Hey guys how far is everyone into this unit and which chapters are your favorite and worst. Im on Lungs and Disease right now and its my favourite topic so far. How is everyone revising for it? atm I'm just doing notes from the book and going over them alot and just doing the exam qs at the end of the chapters and using a seperate book just to master the possible big questions and rewrite them according to the markscheme later. Also are there any other resources that I could use before starting past papers as soon as I finish the sixth chapter?.

http://www.google.co.uk/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&sqi=2&ved=0CC8QFjAA&url=http%3A%2F%2Fwww.heckmondwikegrammar.net%2FgetObject.php%3Furl%3D%252Fweb_files%252Fdepartments%252Fbiology%252FFile%252FUnit_1_Notes.pdf&ei=9opIU_-LBqXP0AXy2oD4DA&usg=AFQjCNGzg4-GQrEko172ulc5CQr8UNuQtw&sig2=9sFMZs8FdFWumYW-dU_DUQ&bvm=bv.64542518,d.d2k

this is very useful-has everything in the aqa book-put in a simpler form :biggrin:

Reply 55

just looking up this random shiz on active transport and passive transport and this guy gave some really good analogies that I thought you guys may wanna read -

So active transport is the movement of solutes (or molecules - whichever rocks your boat) across a plasma membrane from a region of low concentration to a region of high concentration which requires energy. [Think of this as you requiring energy to carry pebbles from a small valley up and putting them on a huge pile of pebbles at the top of the valley.]

Passive transport would be the movement of solutes down the concentration gradient across a plasma membrane from a region of high concentration to a region of low concentration. [Think of how water flows naturally from the top of the waterfall down to the lake below without any help.]

whadyah think?

(edited 10 years ago)

Reply 56

Original post by tammy:)

just looking up this random shiz on active transport and passive transport and this guy gave some really good analogies that I thought you guys may wanna read -

So active transport is the movement of solutes (or molecules - whichever rocks your boat) across a plasma membrane from a region of low concentration to a region of high concentration which requires energy. [Think of this as you requiring energy to carry pebbles from a small valley up and putting them on a huge pile of pebbles at the top of the valley.]

Passive transport would be the movement of solutes down the concentration gradient across a plasma membrane from a region of high concentration to a region of low concentration. [Think of how water flows naturally from the top of the waterfall down to the lake below without any help.]

whadyah think?

Omg I LOVE YOU!!! I swear if only I knew how to rep you from a tab I so would a 1000x (if thats even possible )

Thankyou so much for sharing the other link and the useful analogies AND for answering the hearts&lungs Qs :biggrin:

Reply 57

Original post by TSRuserrr9

Omg I LOVE YOU!!! I swear if only I knew how to rep you from a tab I so would a 1000x (if thats even possible )

Thankyou so much for sharing the other link and the useful analogies AND for answering the hearts&lungs Qs :biggrin:

no problem. call me an idiot but I actually stayed up all night revising bio unit 1 and rn I am exhausted-good thing I took a 3hour nap yest otherwise idk how I would've worked it minus the caffeine :titan:

I ll try to answer your prev question later on lol

Reply 58

Original post by tammy:)

no problem. call me an idiot but I actually stayed up all night revising bio unit 1 and rn I am exhausted-good thing I took a 3hour nap yest otherwise idk how I would've worked it minus the caffeine :titan:

I ll try to answer your prev question later on lol

Wooooooah!thats pure focus and dedication, more like im the idiot tbh wasted time on YouTube till like 3am :L I think you ought to take a long sleep now tho.u defo need it haha,hopefully someone else answers , my other Question on glucose transport :biggrin:

Reply 59