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Biology hsc exam who ready!! (3 Viewers)

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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

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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.
 
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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

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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

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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

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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
 

Xcelz

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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.
 

Brontecat

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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?
 
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Xcelz

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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.
 

Xcelz

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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.
 

Xcelz

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

Xcelz

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secretion isnt in the syllabus is it?
in the syllabus it doesn't specifically mention secretion but it is part of the active transport associated with kidneys as the toxins that diffused back in the blood are actively secreted into the nephron.

hope you see what i'm tryin to say.
 

Brontecat

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thankyou so much Xcelz - im suprised ur not on golden rep yet

good luck with the exam tomorrow to everyone :D
 

kevda1st

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Whats the enzyme that makes mRNA???

also do u guys think hormone replacement/renal dyalysis will come up??
 

Xcelz

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haha thanks, any more questions post them up please. or if anybody wants we can alternate questions.
 

Xcelz

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Whats the enzyme that makes mRNA???

also do u guys think hormone replacement/renal dyalysis will come up??
well there was a 5 mark question on hormone activity last year which isn't exactly hormone replacement but similar. if a question did turn up it would be more likely on this than hormone activity.
 
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