biology prac assessment! (1 Viewer)

[Mays]

hello!:wave:
heh! my first post lol beginner

any ways...just wanted to ask if anyone has done their prac assessment yet..if so what were u tested on?

and any thing to look out for?
...thanks

 

[untamedanimal]

I dont know if its what you are talking about but we just got an assignment to design an experiment to test affects of Co2 on pH in blood

 

[felafel]

yeah . . . i've had two prac assessments so far (but i can't remember the first!)

in the second one, we had to examine two microscopic adaptations (ie. adaptations that couldn't be seen by the naked eye) of plant leaves to minimise water loss - explain then draw them

 

[Zarathustra]

I know part of my prac. will be on growing bacteria cultures - hope I do better in this one than in prelim.

 

[nicko88]

has anybody done the open-ended investigation assessment task yet? the one where u have 2 design ur own experiment n do a presentation? if so, can u tell me whats a good topic i can do? thanx

 

[s0k0y0e0]

hey!

I did an open-ended investigation, but it was last year!

We had to do it on one Australian animal and plant and investigate their population and variations in the population and make in different areas of Australia!

Dunno if that's any help! Soz!

 

[Smiddy]

hey,
our prac was on the effect of temp on enzymes, was a breeze! i think i went overboard with my discussion though it was like nearly 1.5 pages long? oh will have to wait adn see wat my mark was i guess

 

[Lil Clutch]

yeah my prac was on enzymes as well- ours was in two parts, one was to measure the effect of different ph on enzyme, and all our results were that the enzyme worked best at ph7. and the second part was a written exam based on the prac. in the first part, we had a double period to carry out the prac and then write up a prac report, ie-aim, method, observations, results, analysis of results, conclusion, safety and risk analysis and while we were doing our pracs the teachers went around to see if we were using pipettes properly, and disposed of wastes safely, and wore goggles, etc. the prac report was marked real hard thou- you had to be careful to write about independent and dependent variables and controls, etc in the correct sections of the report. thats where i lost my marks- managed to get 22/25 thou- pretty stoked, compared to my prelim results. i hope hsc biology is tonnes better! aye? oh yeah, in the second part- it was like a test we had to draw a graph, conclude results from a table and there were some multiple choice questions. well have fun in your holidays! and good luck in 2005!

 

[Smiddy]

what enzyme did u test? the enzymes we have been testing are those found in the stomach such as pepsin and rennin. However the pH is lower than 7 cos the stomach is acidic and not neutral. so we found that the pepsin ect worked best at a pH of two. Im interested to see what enzymes u used, and where they react best at, if their optimum was a pH of 7?

 

[Lil Clutch]

hey our prac was to show that ph affects the activity of catalase in potato tissue and to estimate the optimum pH. and the results showed that the enzyme catalase is most effective under neutral conditions. however we tested ph3, ph5, ph7 and ph9. and some people got ph9 as their result. so to make the results morre valid, we said we should experiment it again this time with smaller incriments, ie. ph7, ph8 and ph9. so some people concluded that it could also work best in slightly alkaline conditions. we have also experiment with renin, from junket tablets- but we did temperature for that. ie tested the activity of renin at different temperatures, and the activity was based on the time it took for the milk to curdle. what did u do?

 

[Smiddy]

We did all three. temp, pH and substrate. First we did the temp one with pepsin, aka the substance in the stomach with brakes the food down. but it didnt work that well, it was extremely hard to get the pepsin at the right pH which was 2. so the results werent that clear adn we did repeat it but the results didnt really proved much. The ones we did with the junket (rennin) worked really well, except for the temperature. The temp one worked if u had the background knowledge that milk would cook at temp above 37 degrees. i knew this cos i do hospo, so my results were right but the rest of class put that the optimum temp was like boiling pt cos it reacted quickest, but infact the experiment was tesing for the milf to curdle which is a different effect to cooking. we did this one for our test so i think that i might do better than every1 else cos i knew the difference between the milk curdleing and cooking. meh who knows i dont get the results till we go back but yeah.

 

[Lil Clutch]

well good luck with what you get. u sound like you know what ure doing. we did our pracs very early in the term- like week 5. so there was plenty of time to get our results etc. but out prac was really easy. i agree with the junket one, it was hard testing with temperature. everyone paired up in our class and experimented on different temperatures. i got 10'c so obviously there were no results there. but our results showed that 40 was otpimum. once again if we had time to repeat it we wouldve tried with smaller incrimants between our temperatures. ie- 35, 40, 45 we had every ten. anyway- good luck! i did well im sure u will too!

 

[tunes9]

I was just wondering what was measured with renin in junket tablets? and how it was done. Our examination is the effect of the change in pH on an enzyme of our choosing. We are given solutions of different pH's, eg 2,4,6,8,10,12 and are given 20min for the prac. What exactly would i do to find the effect?

 

[angmor]

we did using temperture to find out the effects of change on the activity rate of the enzyme+substrate reaction...pretti straightfoward but it took us a long time sitting there waiting for temp to go up or down xD....we used milk and rennin as substrate and enzyme....i think thats what the whole state used?

 

[DraconisV]

we in our class we have doen 7 pracs so far, our teacher marks them in our prac books, but they arent really worth much, i guess they add up to a prac exam mark thingymajiggy

 

[angmor]

should be worth 10% of the internal mark, which i would guess to be around 5% of the total mark? so yeah its still something worth studying for.

 

[Dr_Doom]

hey,
our prac was on the effect of temp on enzymes, was a breeze! i think i went overboard with my discussion though it was like nearly 1.5 pages long? oh will have to wait adn see wat my mark was i guess

Wow really can you send it to me for ideas lol?

 

[shellbell91]

hi i was wondering what you did for the substrate-enzyme prac?? i have a assessment tomorrow (only remembered today) and was hoping you could give me some tips?