Gibberellin coursework

jonopye

On the paper it says the concentraion of the gibberellic acid is 3x10 mol dm-3 does that mean 30mol dm-3

No, it's a typo.

It's meant to read:

3 \times 10^{-3}

mol dm-3

On the next line is also says 3mmol dm-3 (which is the same at 10^-3).

Reply 45

also stuck on this coursework. however i do have an outline of a method, and preliminary method.

from my preliminary method i hope to find out the best volume of starch to use in the main experiment as i am going to time how long it takes to breakdown and don't want the experiment to go on too long. how do i find out the best volume when i am not able to do the preliminary experiment as i am on my easter holidays????

also, i plan to soak my seeds in the different concentrations of gibberellins how long would anyone suggest to do this for? do i need to cut the seeds in half??? and only use one half..... my method is to soak the seeds mush them up and add them to starch and iodine solution then time how long it takes for the iodine to go back to its orangy colour

would you say a water bath is needed???

and what volumes of gibberellins do you think would be best to use??

any help would be much appreciated :biggrin:

Reply 46

jackford

does anybody know how to make the serial dilutions. i mean making 100umol is easy but how about 90, 80 etc...

Reply 47

i used ratios with water, like if u have 10 cm3 for a 90umol use 9 cm3 of gibberellin and 1 cm3 of water...i think

Reply 48

TheTallOne

It's in here somewhere. :eek:

Basically, there's one method involving starch-agar and seed halves (with a past paper which mirrors what we're meant to do).

There's also a Benedict's test method, involving the use of a glucose dilution series.

That's all I'm prepared to give, based on what is written in the sheet that we were given.

Make sure you calculate the concentrations and volumes that you require for the proposed method (not the pilot). Basically, go through your method step by step and count what you need.
Eg; 1) Germinate the seeds

Therefore I need seeds, a place and a solution to germinate them. Find out how many time you're doing to do this, then find the mass of seeds you require.

so i don't need an equipment list for my preliminary method?

Reply 49

K-T

so i don't need an equipment list for my preliminary method?

You do, but you have you work that out yourself.

Reply 50

TheTallOne

You do, but you have you work that out yourself.

thanks

its a good job i wrote one hehe, i don't suppose you could answer some of my questions from an earlier post??

Reply 51

K-T

also stuck on this coursework. however i do have an outline of a method, and preliminary method.

from my preliminary method i hope to find out the best volume of starch to use in the main experiment as i am going to time how long it takes to breakdown and don't want the experiment to go on too long. how do i find out the best volume when i am not able to do the preliminary experiment as i am on my easter holidays????

also, i plan to soak my seeds in the different concentrations of gibberellins how long would anyone suggest to do this for? do i need to cut the seeds in half??? and only use one half..... my method is to soak the seeds mush them up and add them to starch and iodine solution then time how long it takes for the iodine to go back to its orangy colour

would you say a water bath is needed???

and what volumes of gibberellins do you think would be best to use??

any help would be much appreciated :biggrin:

Germinate the seeds for at least 24 hours. Crushing the seeds is then fine. Use some reasonable concentrations of GA - not excessively small - maybe work at 10-20% dilution intervals.

Water bath should not be needed, if you do use on, remember you're dealing with enzymes.

Reply 52

went for conc of 0.1 gdm-3, 0.2, 0.4, 0.6, 0.8 and 1 that sound ok?? in 10cm3 solutions

Reply 53

Pirouette

10

What I don't understand is why they've given us such a massive concentration of giberellic acid in comparison to what is normally found in plants. Why would they tell us the normal concentration in plants if they didn't want us to use that teeny amount? Also, I seem to not be doing my method in the same way as any of you. I'm using starch-agar in Petri dishes and iodine? Eek I'm worried.

Reply 54

Pirouette

10

K-T

also stuck on this coursework. however i do have an outline of a method, and preliminary method.

from my preliminary method i hope to find out the best volume of starch to use in the main experiment as i am going to time how long it takes to breakdown and don't want the experiment to go on too long. how do i find out the best volume when i am not able to do the preliminary experiment as i am on my easter holidays????

also, i plan to soak my seeds in the different concentrations of gibberellins how long would anyone suggest to do this for? do i need to cut the seeds in half??? and only use one half..... my method is to soak the seeds mush them up and add them to starch and iodine solution then time how long it takes for the iodine to go back to its orangey colour

would you say a water bath is needed???

and what volumes of gibberellins do you think would be best to use??

any help would be much appreciated :biggrin:

Iodine isn't an indicator in the same sense as phenolphthalein or universal indicator, it won't change colour.

Reply 55

Roma1234

hiya, i was just wondering which paper is this that mirrors the method?
is it central concepts?
and what year?
thankyou x

Reply 56