practice exam questions help

[ellie7g]

So i have a few questions from various exams that i'm unsure about-

-insight 2011 exam 1, question 1: it gives some context about a drug called DNP thats used in diet pills. The question asks "DNP is probably the best known agent for uncoupling oxidative phosphorylation. What processes are normally coupled in oxidative phosphorylation?" I have never even heard those words before. Is this stuff beyond the scope of the course? Should i worry about this or move on?

-insight 2012 exam 1, question 1: "what is the name given to the non-protein component of hemoglobin?" Again, i haven't come across something like this is any exam or even my notes/textbook. On the course?

-Engage exam: :"enzyme A catalyses the production of protein C, which binds to the allosteric enzyme Y, which changes it's active site to provide a platform for substrates B and D to join to synthesis enzyme X, which has an inhibitory effect on enzyme Y. Enzyme Y is allosteric, An allosteric enzyme is...." what the hell is an allosteric enzyme? Never heard of this before.

-this question is applicable to those who have completed the Engage exams that were released this year. I'm not really sure which number exam it is but it's multiple choice 24. It gives a pedigree chart and asks for the mode of inheritance. The chart shows an affected female giving rise to both an affected female and male. this male then gives rise to two affected females. another affected female gives rise to a male and female. The answer says it is x-linked dominant. But wouldn't it be autosomal dominant? is the answer wrong?

thanks in advance to anyone who can help me out!

[ellie7g]

Also- i came across this multiple choice question:
"a signal molecule that binds to a plasma membrane protein function as a:" the answer was "ligand"
according to the suggested answers, a ligand specifically binds to another molecule and causes a receptor protein to undergo change in shape. I looked in the nature of biology book and couldn't find this term- on the course?
i think it's clear i'm hoping that all the things i haven't heard of, are just not on the course haha

[ellie7g]

Engage exam
- "the half life of carbon 14 is approx 5730 years. If a sample of coal was dated to determine its age and was found to have 1/8 of its original amount if carbon 14, how old would it be?" Answer is "5730 x 3 years".

-"plants adapted to live in hot dry conditions are" answer is "xerophytes". Is this on the course?

Thanks in advance :)

[Yacoubb]

So i have a few questions from various exams that i'm unsure about-

-insight 2011 exam 1, question 1: it gives some context about a drug called DNP thats used in diet pills. The question asks "DNP is probably the best known agent for uncoupling oxidative phosphorylation. What processes are normally coupled in oxidative phosphorylation?" I have never even heard those words before. Is this stuff beyond the scope of the course? Should i worry about this or move on?
It's just aerobic cellular respiration - the formation of ATP (when ADP is phosphorylated). You wouldn't be expected to know it in that terminology sense.

-insight 2012 exam 1, question 1: "what is the name given to the non-protein component of hemoglobin?" Again, i haven't come across something like this is any exam or even my notes/textbook. On the course?
Prosthetic group - not necessarily on the course, but handy to know just in case.

-Engage exam: :"enzyme A catalyses the production of protein C, which binds to the allosteric enzyme Y, which changes it's active site to provide a platform for substrates B and D to join to synthesis enzyme X, which has an inhibitory effect on enzyme Y. Enzyme Y is allosteric, An allosteric enzyme is...." what the hell is an allosteric enzyme? Never heard of this before.
I haven't heard of an allosteric enzyme (not on the course). But, I'd advise you to know that when dealing with non-competitive inhibitors for enzymes, just remember that they bind to the allosteric region of an enzyme. That is, they do not attach to the active site of the enzyme, but rather another part of the enzyme, inducing a chance in the tertiary shape of the enzyme's active site.

-this question is applicable to those who have completed the Engage exams that were released this year. I'm not really sure which number exam it is but it's multiple choice 24. It gives a pedigree chart and asks for the mode of inheritance. The chart shows an affected female giving rise to both an affected female and male. this male then gives rise to two affected females. another affected female gives rise to a male and female. The answer says it is x-linked dominant. But wouldn't it be autosomal dominant? is the answer wrong?
It could be X-linked dominant. Actually, it is. If the affected female is a heterozygote for the trait, there is a chance she may have affected offspring. Remember, males only inherit one X-chromosome paternally. The X-chromosome inherited could carry the allele of the trait (at its respective gene locus), and thus because it is dominant, will be phenotypically expressed in males. However, females, who also inherit one X-chromosome maternally, may inherited the X-chromosome carrying the allele for the trait; hence, because it is dominant, it will be phenotypically expressed. Thus, it is X-linked dominant. Note that you actually rarely get asked pedigree questions where you are asked to find the mode of inheritance for dominance. Unless you've been given sufficient info, its usually very difficult to distinguish between it being sex-linked or autosomal.

Engage exam
- "the half life of carbon 14 is approx 5730 years. If a sample of coal was dated to determine its age and was found to have 1/8 of its original amount if carbon 14, how old would it be?" Answer is "5730 x 3 years".
If only 1/8 of the original carbon 14 remains, this means that the Carbon-14 sample has gone through 3 half-lives. That is, 1/2 x 1/2 x 1/2 = 1/8. Hence, to find the age of the coal, you multiply the number of half-lives undergone (i.e. 3) by the half-life of the radioactive element (C14).

-"plants adapted to live in hot dry conditions are" answer is "xerophytes". Is this on the course?
You don't need to know this.

Also- i came across this multiple choice question:
"a signal molecule that binds to a plasma membrane protein function as a:" the answer was "ligand"
according to the suggested answers, a ligand specifically binds to another molecule and causes a receptor protein to undergo change in shape. I looked in the nature of biology book and couldn't find this term- on the course?
i think it's clear i'm hoping that all the things i haven't heard of, are just not on the course haha

A ligand is any molecule that binds to a reception site/active site of a biomacromolecule. E.g. a substrate would be the ligand that binds to an enzyme (i.e. a protein). E.g. a peptide hormone that binds to a specific receptor on the cell membrane of target cells is the ligand. I don't think VCAA would expect you to know this; but hey, its good to have up your sleeve just in case.

Hope this helped ellie7g

[ellie7g]

Hope this helped ellie7g

 thanks Yacoubb! massive massive help! happy studying!

[ellie7g]

This is probably a bit of a silly question but I'm just really curious. since proteins, namely enzymes, can be inactivated/denatured due to temps and ph outside of the optimal range, can glycoproteins also be affected? Or does that not really happen since they're also composed of carbohydrates?

[swagsxcboi]

Hope this helped ellie7g

Remember, males only inherit one X-chromosome paternally maternally

[Yacoubb]

Remember, males only inherit one X-chromosome paternally maternally

Oops that was a typo! A really bad one! But I think Ellie got the picture:)