11th January 2012 - 6BIO1 - edexcel biology unit 1

Original post by Dan9878

Is the answer not to do with say high blood pressure, lack of activity, smoking etc.,

If its not I'd talk about atherosclerosis.

well yeh those things cause atherosclerosis but how it develops ..?! it develops thru two things clot formation and and all the fatty deposit collection ! which one do i write ..??!!?!

Reply 182

Original post by moizedexcel

well yeh those things cause atherosclerosis but how it develops ..?! it develops thru two things clot formation and and all the fatty deposit collection ! which one do i write ..??!!?!

Id talk about atherosclerosis. I dont think CVD is likely to cause a clot formation. As you need damage to a blood vessel. Atherosclerosis only needs damage to the endothelial lining.

EDIT not sure i understand your question. Atherosclerosis and clot formation are totally different things

(edited 12 years ago)

Reply 183

Original post by Dan9878

Id talk about atherosclerosis. I dont think CVD is likely to cause a clot formation. As you need damage to a blood vessel. Atherosclerosis only needs damage to the endothelial lining.

EDIT not sure i understand your question. Atherosclerosis and clot formation are totally different things

im sorry i confused my question to myself !! ;p im saying if they what can damage to endothelial cells cause ..?! it can cause botht he things clot formation and atherosclerosis ryte ...???? so what am i suposed to write ..?!

Reply 184

Original post by Dan9878

Id talk about atherosclerosis. I dont think CVD is likely to cause a clot formation. As you need damage to a blood vessel. Atherosclerosis only needs damage to the endothelial lining.

EDIT not sure i understand your question. Atherosclerosis and clot formation are totally different things

But the atheroma that forms in the blood vessel can rupture or break of which would cause the clotting mechanisms to occur. Also because athersclerosis makes the arteries very weak and brittle and therefore under BP it could cause an aneurism which would almost certainly = Brown Bread

(edited 12 years ago)

Reply 185

Original post by Spunky_Monkey

But the atheroma that forms in the blood vessel can rupture or break of which would cause the clotting mechanisms to occur. Also because athersclerosis makes the arteries very weak and brittle and therefore under BP it could cause an aneurism which would almost certainly = Brown Bread

which textbook is that in ?

Reply 186

Original post by moizedexcel

im sorry i confused my question to myself !! ;p im saying if they what can damage to endothelial cells cause ..?! it can cause botht he things clot formation and atherosclerosis ryte ...???? so what am i suposed to write ..?!

Damage to endothelial lining = atherosclerosis

Damage to a blood vessel ie cut or graze = Blood clotting.

This is what my revision guide says. Do you have a copy of the question troubling you?

Reply 187

Original post by Dan9878

Damage to endothelial lining = atherosclerosis

Damage to a blood vessel ie cut or graze = Blood clotting.

This is what my revision guide says. Do you have a copy of the question troubling you?

i saw that question like in a paper of 2001 something :tongue:

it said something which i dont remember :tongue:

but i was hundred percent sure that the answer was atherosclerosis .....but when i saw the mark scheme it said BLOOD CLOTTING stuff !! i was pissed ....:O

Reply 188

Original post by Dan9878

which textbook is that in ?

A mixture of the CGP revision guide and my teachers.
The clotting can happen after the dislodged atheroma has been ruptured because of the stickiness of the platelets which release chemicals for thrombosis to occur. But the actual atheroma can be enough to starve vital organs of oxygen and glucose if enough of them - CHD

(edited 12 years ago)

Reply 189

To anyone wandering about the atheroma thrombosis section this clears things up a bit:

What is atheroma (atherosclerosis)? http://www.patient.co.uk/health/Atheroma.htm

Patches of atheroma are like small fatty lumps that develop within the inside lining of arteries (blood vessels). Atheroma is also known as atherosclerosis and 'hardening of the arteries'. Patches of atheroma are often called plaques of atheroma.

Over months or years, patches of atheroma can become larger and thicker. So, in time, a patch of atheroma can make an artery narrower, which can restrict and reduce the blood flow through the artery.

Sometimes a patch of atheroma may develop a tiny crack or rupture on the inside surface of the blood vessel. This may trigger a blood clot (thrombosis) to form over the atheroma which may completely block the blood flow.

Remember that atheroma's can become dislodged from their original place of development and can therefore cause problems elsewhere in the body - possibly the development of deep vein thrombosis. Just because it says thrombosis it does not mean that atheroma's do not play a part in the development of clots.

Reply 190

Original post by moizedexcel

i saw that question like in a paper of 2001 something :tongue:

it said something which i dont remember :tongue:

but i was hundred percent sure that the answer was atherosclerosis .....but when i saw the mark scheme it said BLOOD CLOTTING stuff !! i was pissed ....:O

Old spec has a few different things in it. I wouldn't worry about it.

Reply 191

wag1

Anyone know how to answer a 6mark question on the experiment about enzyme concentration on potatoe slices or something similar? because i dont know jack **** about that experiment.

Fore example this is my 6mark answer which would get full marks to the experiment testing the effect of caffeine on daphnia.

Firstly you would place daphnia and caffeine into a test tube and let them acclamatise (let the daphnia become affected by the caffeine to make sure the daphnia have been exposed to the caffeine) then you would place the daphnia on a cavity slide which you would place under a microscope. You would then focus on the heart of the daphnia using the microscope to count the heart beat per minute. An easy way of doing this would be counting the number of heart beat for 10 seconds then times that number by 6 to get per minute and use a stopwatch. Then you would repeat this experiment 2 more times and calculate the mean heart rate. Your control variable would be the concentration of caffeine used. You would then repeat this experiment 3 times using daphnia that have not been exposed to caffeine, calculate the mean heartbeat per minute then see what the effect of caffeine does to the daphnia.

^ That would be a full 6 mark answer for a question on the experiment of caffeine on daphnia or whatever organism they ask in the exam.

Anyone kind enough to write a 6 marker for the experiment on enzyme concentration on potato slices? :smile:

(edited 12 years ago)

Reply 192

Original post by wag1

Anyone know how to answer a 6mark question on the experiment about enzyme concentration on potatoe slices or something similar? because i dont know jack **** about that experiment.

Fore example this is my 6mark answer which would get full marks to the experiment testing the effect of caffeine on daphnia.

Firstly you would place daphnia and caffeine into a test tube and let them acclamatise (let the daphnia become affected by the caffeine to make sure the daphnia have been exposed to the caffeine) then you would place the daphnia on a cavity slide which you would place under a microscope. You would then focus on the heart of the daphnia using the microscope to count the heart beat per minute. An easy way of doing this would be counting the number of heart beat for 10 seconds then times that number by 6 to get per minute and use a stopwatch. Then you would repeat this experiment 2 more times and calculate the mean heart rate. Your control variable would be the concentration of caffeine used. You would then repeat this experiment 3 times using daphnia that have not been exposed to caffeine, calculate the mean heartbeat per minute then see what the effect of caffeine does to the daphnia.

^ That would be a full 6 mark answer for a question on the experiment of caffeine on daphnia or whatever organism they ask in the exam.

Anyone kind enough to write a 6 marker for the experiment on enzyme concentration on potato slices? :smile:

It depends what they want the independent variable to be it might be the size of the potato as more potato (more catalase) or the amount of hydrogen peroxide (substrate)

So write about preparing what IV they are asking for then using a test tube to complete the reaction where the catalase in the potato will react with the hydrogen peroxide, to give water and oxygen as products, for a minute and use a feeding tube at the top so that the 02 diffuses into a syringe to work out how much 02 is given off. Then divide amount produced by time to give initial ROR. Do all the repeated to validate rah rah keep temperature and amount of time measuring the same, wear goggles, plot on a graph. You could also say alternatives to this method would be to count the oxygen bubbles given off but that it would be unreliable. - I reckon this one or Daphnia will come up because this time last year membrane permeability came up and in june DCPIP and Semi conservative replication testing for DNA came up for like 15 marks in total.

(edited 12 years ago)

Reply 193

Original post by wag1

Anyone know how to answer a 6mark question on the experiment about enzyme concentration on potatoe slices or something similar? because i dont know jack **** about that experiment.

Fore example this is my 6mark answer which would get full marks to the experiment testing the effect of caffeine on daphnia.

Firstly you would place daphnia and caffeine into a test tube and let them acclamatise (let the daphnia become affected by the caffeine to make sure the daphnia have been exposed to the caffeine) then you would place the daphnia on a cavity slide which you would place under a microscope. You would then focus on the heart of the daphnia using the microscope to count the heart beat per minute. An easy way of doing this would be counting the number of heart beat for 10 seconds then times that number by 6 to get per minute and use a stopwatch. Then you would repeat this experiment 2 more times and calculate the mean heart rate. Your control variable would be the concentration of caffeine used. You would then repeat this experiment 3 times using daphnia that have not been exposed to caffeine, calculate the mean heartbeat per minute then see what the effect of caffeine does to the daphnia.

^ That would be a full 6 mark answer for a question on the experiment of caffeine on daphnia or whatever organism they ask in the exam.

Anyone kind enough to write a 6 marker for the experiment on enzyme concentration on potato slices? :smile:

hey ! im confused a bit !! u fiirst acclimatised the Daphnia and then put it on a cavity slide with caffeine right ...?!?! then whats the use of acclimatisation ...?!? ok and then the daphnia who have not been exposed to caffiene would act differently in caffiene solutions ....ummmm y even they are getting EXPOSED to caffiene and sooner or later WILL acclimatise......also shouldnt v mention a control daphnia in plain pond water ...?!?!!? hmmmmmmm .?! :confused:

(edited 12 years ago)

Reply 194

so in every gene therapy there is a need for repeat ..?! i thought its only needed for cystic fibrosis beacuse the cells are shed of and replaced by cells containing faulty gene .....but in the mark scheme its written for thalasaemia too ....?!?!

Reply 195

A_TVDx

The way edexcel asks their questions is so confusing half the time!!

Reply 196

InadequateJusticex

18

Original post by A_TVDx

The way edexcel asks their questions is so confusing half the time!!

I agree

Sometimes they're poorly worded and the mark scheme is highly specific. Not a great combination...

Reply 197

aqua05

OP

9

Helloo everyone !
Can anyone help me with an answer to the following question?

How does the primary structure help determining the shape of the protein ? (5marks)

Reply 198

jasmine124

Original post by Lilmzbest

doesn't look like anyone else has mentioned this :confused:

actually REALLY helpful, nice concise notes for quick revision over the whole exam topics, thanks a lot :smile:

These are bloody amazin notes :biggrin:

Reply 199