AQA A2 BIOL5 22nd June 2012

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An essay on:
'The ways in which organisms use ATP', I have:

Co-transport - Unit 1 stuff- K+ Na+ pump
-Glycolysis;
- Photosynthesis - Light independent (but also introduce by light dependent)
- Muscle contraction - unit 5 stuff.
-ATP adaptations - small but manaegeable amount of energy.. blabla
??????????? HELP1?!
I thought this would have loads to talk about, but tbh, there's not much really ... :/

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You could mention second messenger of ATP in control of blood glucose - cAMP.

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The ATPPC system - an anaerobic system used for energy in muscle contraction - ADP + PCr -> ATP + Cr

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don't forget the Na+ K+ pump in maintaining resting potential

Reply 441

whc23

Good luck with the revision everyone. I'm currently marking undergraduate essays and I have one piece of advice. Please write legibly in your exam to maximize your chances of getting the marks. Please see my blog:

http://cambridgeacademic.blogspot.co.uk/

Reply 442

rss.914

Original post by JJMick

Don't know what part you want help with, the big picture is:

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A Restriction endonuclease is used to isolate the fragment by it cutting at recognition sites either side of the fragment - sticky ends are left.

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A plasmid is used as a vector and is cut with the same restriction enzyme that was used to isolate the fragment. The fragment is then mixed with the plasmid and due to the sticky ends the fragment fits in with the help of DNA Ligase which joins the sticky ends

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The vector then inserts the gene into a host cell, some techniques are used to increase chance of uptake (e.g. CaCl₂ and/or heat shocking)

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Transformed host cells are then identified either by the older method of using replica plating to identify with antibiotic resistance or nowadays the use of fluorescent labels are used (the marker genes for this is added to the vector during that stage)

so once you identify the transformed host cell do you increase the number of transformed host cells?

Reply 443

MustyQ

i need help with things off the syllabus for ion essay :frown:

anyone??

Reply 444

JJMick

Original post by rss.914

so once you identify the transformed host cell do you increase the number of transformed host cells?

Yeah the transformed cells are allowed to multiply.

Reply 445

narnia123

Original post by MustyQ

i need help with things off the syllabus for ion essay :frown:

anyone??

what is the actual title of the essay?

Reply 446

MustyQ

Original post by narnia123

what is the actual title of the essay?

inorganic ions include those of sodium, phosphorus and hydrogen. Describe how these and other inorganic ions are used in living organisms? :colone:

Reply 447

F1's Finest

Original post by MustyQ

inorganic ions include those of sodium, phosphorus and hydrogen. Describe how these and other inorganic ions are used in living organisms? :colone:

That's a little narrow. I doubt they would ask that, but they would most likely ask 'Describe how organic ions are used in living organisms'

Remember that nitrates makes up a big part of the syllabus (especially in unit 4) so they wouldn't disregard it when making an essay title for our exam.

Reply 448

narnia123

Original post by MustyQ

inorganic ions include those of sodium, phosphorus and hydrogen. Describe how these and other inorganic ions are used in living organisms? :colone:

I know for a fact i'd be bricking it if this came up in the exam. Im pretty crap at thinking of stuff to put in essays, but i'd say you could talk about:
-Ca ions in muscle contraction and synapses
-Cl ions in post synaptic membranes
-Na/K pump
-H bonding of water molecules (transpiration pull in plants)? not too sure about that one
-Na ions in action potentials
-H in DNA
Sorry there's not much and some might be wrong :biggrin:

Reply 449

JJMick

MustyQ

inorganic ions include those of sodium, phosphorus and hydrogen. Describe how these and other inorganic ions are used in living organisms?

Original post by narnia123

I know for a fact i'd be bricking it if this came up in the exam. Im pretty crap at thinking of stuff to put in essays, but i'd say you could talk about:
-Ca ions in muscle contraction and synapses
-Cl ions in post synaptic membranes? don't you mean Na ion channels
-Na/K pump
-H bonding of water molecules (transpiration pull in plants)? not too sure about that one
-Na ions in action potentials
-H in DNA
Sorry there's not much and some might be wrong :biggrin:

In addition:

H+ ions in respiration.
Phosphate group in DNA.
Nitrate/nitrite/ammonium ions in nitrogen cycle etc.
Phosphate ions in ATP etc.

There's plenty to talk about.

Reply 450

narnia123

Original post by JJMick

In addition:

H+ ions in respiration.
Phosphate group in DNA.
Nitrate/nitrite/ammonium ions in nitrogen cycle etc.
Phosphate ions in ATP etc.

There's plenty to talk about.

Could you actually explain the Cl ion thing to me, i dont think I quite understand it :L

Reply 451

rss.914

Original post by JJMick

Yeah the transformed cells are allowed to multiply.

so for the essay title "uses of DNA in science and technology" i could use in vivo cloning and the pcr?

Reply 452

F1's Finest

Original post by rss.914

so for the essay title "uses of DNA in science and technology" i could use in vivo cloning and the pcr?

Yes, PCR is used to make rapid copies of DNA, which is useful from a crimescene for instance where many tests need to be carried out on the DNA......

Reply 453

rss.914

Original post by James A

Yes, PCR is used to make rapid copies of DNA, which is useful from a crimescene for instance where many tests need to be carried out on the DNA......

ohh, for genetic modification what can you write, all i know is one sentence which is the use of recombinant dna

Reply 454

301lw

can someone please explain the apoplastic and symplastic pathway? i was going through AS stuff and don't remember this bit at all :frown:

Reply 455

JJMick

Original post by rss.914

so for the essay title "uses of DNA in science and technology" i could use in vivo cloning and the pcr?

Well there is lots more to talk about really...

-genetic fingerprinting - useful in forensics and in medicine
-DNA probes for genetic screening
-genetic engineering - GM crops, animals, etc
-gene therapy

from AS:
-DNA hybridisation

Reply 456

JJMick

Original post by 301lw

can someone please explain the apoplastic and symplastic pathway? i was going through AS stuff and don't remember this bit at all :frown:

The apoplastic pathway goes through the non-living parts of the plant cells - so the cell walls, this pathway stops however as there is a waxy casparian strip in the endodermis layer of cells. This means that the water has to then use the symplastic route which means that the movement of substances can be controlled more.
the symplast pathway uses the living parts of the cells - through the cytoplasm using plasmodesmata between the cells, this is slower that apoplast so about 90% of the water uses the apoplast pathway.

Reply 457

F1's Finest

Personally I would be surprised if one of the following questions didn't come up.

Write about the role of ATP in organisms.

Describe how inorganic ions are used in living organisms.

Write about the importance of carbohydrates in living organisms.

Write about the biological reactions and pathways that occur within living organisms.

Reply 458

oHellno

Omg I've only looked over my AS notes briefly, havne't actually learnt them properly. Plus I avoided all the topics that I find boring. Gah what is wrong with me :sigh: