Biology hsc exam who ready!!

[SmileyFacedTash]

You can hide this advertisement by registering.

do you think the exam will be easier this year since last years paper was a lil harder than usual?

crap still have communication to study

[sam5]

Originally Posted by SmileyFacedTash

do you think the exam will be easier this year since last years paper was a lil harder than usual?

crap still have communication to study

what (specifically) was hard about last years bio paper?

Maybe it will be easier - but they will prolly go for 'different' things to stop the hsc getting stale.

[InaudibleMelody]

Hey guys.

I am having a lot of trouble understanding the relationship between polypeptides and proteins.. What are polypeptides anyway? I know the deal with mRNA and tRNA and how DNA controls the production of polypeptides.. But am so stuck on everything else.


FML x 1000!

[sam5]

Originally Posted by InaudibleMelody

Hey guys.

I am having a lot of trouble understanding the relationship between polypeptides and proteins.. What are polypeptides anyway? I know the deal with mRNA and tRNA and how DNA controls the production of polypeptides.. But am so stuck on everything else.

atoms make up amino acids. Amino acids make up polypeptides. Polypeptides make up proteins.

[Xcelz]

Originally Posted by InaudibleMelody

Hey guys.

I am having a lot of trouble understanding the relationship between polypeptides and proteins.. What are polypeptides anyway? I know the deal with mRNA and tRNA and how DNA controls the production of polypeptides.. But am so stuck on everything else.


FML x 1000!

polypeptides are composed of amino acids linked by peptide bonds. proteins are made up of one or more polypeptide chains.

[Brontecat]

hey with the kidneys i get the whoe filtration and reabsorption part but what do i need to know about secretion??

btw thankyou sooo much to anyone who answers

[annabackwards]

I wish everyone doing biology tomorrow good luck

[Xcelz]

Originally Posted by Brontecat

hey with the kidneys i get the whoe filtration and reabsorption part but what do i need to know about secretion??

btw thankyou sooo much to anyone who answers

§ Secretion: This is the process where the body actively transports substances from the blood into the nephron. Some toxins, such as urea, tend to diffuse back into the blood, so it must be secreted back into the nephron. It is also done to regulate salt and water levels again, or to remove additional toxins. This is active transport.

[InaudibleMelody]

Originally Posted by Xcelz

polypeptides are composed of amino acids linked by peptide bonds. proteins are made up of one or more polypeptide chains.

So is a protein chain the chain of Amino acids joined by the peptide bonds?

[Brontecat]

Secretion: This is the process where the body actively transports substances from the blood into the nephron. Some toxins, such as urea, tend to diffuse back into the blood, so it must be secreted back into the nephron. It is also done to regulate salt and water levels again, or to remove additional toxins. This is active transport.

so its like the beginning and happens before filtration and reabsorption?

[Xcelz]

Originally Posted by InaudibleMelody

So is a protein chain the chain of Amino acids joined by the peptide bonds?

so amino acids form polypetides.

these polyptides are joined by peptide bonds (the bonds between each molecule). thus forming polypetide chains.

protein is made up of one or more of these polypeptide chains.

[InaudibleMelody]

Originally Posted by Xcelz

so amino acids form polypetides.

these polyptides are joined by peptide bonds (the bonds between each molecule). thus forming polypetide chains.

protein is made up of one or more of these polypeptide chains.

Thankyou. So much easier than the textbook I'm reading.

[Xcelz]

Originally Posted by Brontecat

so its like the beginning and happens before filtration and reabsorption

my understanding is that it is done selectively to remove toxins that have diffused back into the blood. logically, these toxins would diffuse back into the blood through the reabsorption stage. the body then actively secretes the toxins that shouldn't have diffused back into the blood.

so from this i gather that is done at the during the final stages of the cycle. but you also have to consider that the process is continuous.

[possessionless]

secretion isnt in the syllabus is it?

[Xcelz]

if you guys have any more questions post them up. i'd be really happy to answer them as it helps me and you.