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AQA BIOL5 Biology Unit 5 Exam - 22nd June 2011

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what could you write for biological importance of water??
i can think of:
osmosis -osmoticlysis
photosynthesis - photolysis of water
cholera
kept as a reserve for co2
blood glucose
condensation reactions???
anything else??? any of these wrong??

Reply 1321

flf

Original post by bobsaeed

hey this is just some ideas
nitrogen:
-important in DNA and Amino acids
-fertilisers

transfer of energy:
-trophic levels and inefficiency though the levels (unit4)
-action potentials
-ATP is the intermediate energy transfer molecule
- energy in chemiosmotic gradients in ETC, H+ runs though ATP synthase causes ATP to be made(Also the electron transport chain in general)

water:
in photosynthesis, water is broken in photolysis into H+ e- and O2, these H+ combines with NADP, e- is used in electron transport chain
-water is wher life started
-hydrolysis reactions breaking ATP and proteins apart
-cystic fibrosis in lungs
-polar so things can dissolve, allowing ions to be formed (plant roots)
-hydrogen bonding, transpiration

surface area:
-Axon diameter effects speed of impulse
-SA in leaf for max light absorbs
-more proteins in higher surface area, e.g. chlorophyll on thylakoid membranes
-SA:V ratio in temp control, heat loss and respiration
-vasoconstriction/dilation

Hydrogen:
-Electron transport chain
-photosynthesis
-co enzymes in respiration, also glycolosis and the actions of NAD
-hydrocarbons, (most organic molecules)
-acidic conditions (caused by H+ ions), Hb in blood
-hydrogen bonds also happen when proteins gain secondary structure

sorry its not much but i hope this is any help and its not to late ahah x :smile:

you guys are good, so detailed! I thought I'd add my own little bit in addition to the notes above for what it's worth :smile:

Nitrogen:
-anaerobic soil causes more denitrification
-nitrogen is needed in DNA’s nucleotides (nitrogenous base)
-nitrogen also makes up amino acids, so needed in proteins

Transfers of energy:
-minimisation of energy loss between trophic levels from agricultural crops to humans and from cattle etc. to humans done through intensive farming and GM foods

Reply 1322

Ramin Gorji

I'm getting worried how people are really going deep in to some of the topics. All im doing is revising through my notes and doing some question in the book :/ Am i being to naive. Also im going to do most of my essay revision on the last day just planning most of the questions they can ask and reviewing key topics of each of the previous units.

Reply 1323

bobsaeed

Original post by flowerscat

@flf

When a tissue is active, it produces more CO2.

CO2 diffuses into the red blood cells and bonds with water forming carbonic acid and releases protons (hydrogen ions)

hydrogen ions lower the pH of the RBC. To prevent a drastic fall in pH, haemoglobin releases its oxygen and takes up the proton.

Overall effect: more CO2 = more oxygen released at that site.

This is called the Bohr effect

yes

x

but i dont think the hemoglobin takes up the proton i think it takes up the co2 an then releaces it in the lungs ......that way u would get rid of the co2 and hence why co2 is released when u exhale

(edited 12 years ago)

Reply 1324

arvin_infinity

SOmeone asked which paper is more similar!! I would say paper BY2 (Probabaly was spec B)

Ask other people as well to play safe

Reply 1325

UCAS.LOVER

is there really no threshold level on neuromuscular junctions like there is on a normal synapse?

Reply 1326

NRican

Anyone have any sample essays or essays that people have posted in this thread before?

TIA.

Reply 1327

bobsaeed

Original post by UCAS.LOVER

is there really no threshold level on neuromuscular junctions like there is on a normal synapse?

there is a threshold level on synapses, or elce what would be the point of temporal symation?

Reply 1328

Flux_Pav

one thing for sure is that IAA will not come up again because its in the specimen and was in the june 2010 paper

Reply 1329

*QueenBeee

hey, i was just wondering whether someone could tell me any tips on writing an essay for synoptic on ions

Reply 1330

angel1992

When a vector is inserted into a plant, the bacterium is usually the vector, so does that bacterium stay on the plant cell?

Reply 1331

flowerscat

Original post by bobsaeed

yes

CO2 is removed from the respiring tissues in 3 ways
1) 5% dissolved in blood plasma
2) 10% bound to haemoglobin as carbaminohaemoglobin
3) 85% as hydrogencarbonate ions
:biggrin:

Reply 1332

flowerscat

Original post by arvin_infinity

Thought its a hormone!!!!! :s-smilie:

For the purposes of AQA Biol 5 exam, adrenaline is a hormone.

Reply 1333

flowerscat

Original post by angel1992

When a vector is inserted into a plant, the bacterium is usually the vector, so does that bacterium stay on the plant cell?

The vector is a plasmid - that grows in bacterial cells. The bacterial cells exist in a symbiotic relationship with the plant host - growing and multiplying slowly in them.

The bacteria used for genetic recombination are modifed to reduce their infectivity and/or slow their growth rate.