Biology AS oct/nov 2010

[kaipai]

(I have modified this q to make it appear organized!!)
Q. This is the mcq on paper 12 bio oct/nov 2010.Plz some one reply. since i dont kno how to add tables or pictures here, I had to spoil the prezentation of the query.

12. Which levels of protein structure are always involved when competitive and non-competitive
inhibitors bind to enzymes?

            competitive                          |               non-competitive
A primary, secondary and tertiary         |           secondary
B quaternary and tertiary                     |          quaternary and tertiary
C secondary                                      |        primary and tertiary
D tertiary                                          |              tertiary

All u people who master bio! Plz reply. This is the humble desire of a Japanese!If u reply , plz tell me how and where u got the answere from?which notes u have that are so exact?And tell me whether u reply it by self wen u first saw it?There is load of such question in papers? how can I solve them?

Thanks!!!!!!!!!!!!

[Deadly_king]

Q.
12. Which levels of protein structure are always involved when competitive and non-competitive
inhibitors bind to enzymes?

competitive non-competitive
A primary, secondary and tertiary secondary
B quaternary and tertiary quaternary and tertiary
C secondary primary and tertiary
D tertiary tertiary

In competitive inhibition, then inhibitors bind to the active site of the enzyme! The latter is formed by tertiary and quaternary structure only

In non-competitive inhibition however, the inhibitors may bind anywhere along the enzyme! In this case, it may be any structure

So most appropriate answer for the MCQ is B

Hope I've been of help

[kaipai]

My textbook (Cambridge endorsed) mary jones biology for A Level doesnt mentions that active site is formed by tertiary and quaternary structures.?? How did you come know this??NOw just tell me how will I know something similar about any other question if my book has not mentioned that?

which notes do you study from and where did you get them from-school, website or self made?

thank you for answering my question.

[Deadly_king]

My textbook (Cambridge endorsed) mary jones biology for A Level doesnt mentions that active site is formed by tertiary and quaternary structures.?? How did you come know this??NOw just tell me how will I know something similar about any other question if my book has not mentioned that?

which notes do you study from and where did you get them from-school, website or self made?

thank you for answering my question.

Okay it may not have mentioned it directly just like that but am sure it's in there Indirectly of course

Anyway give me the definition of active site as well as all those of the protein structures from your book.........if you understand it properly, you'll see how they all fit together

As for me am a medical student, so my knowledge may be a bit far-fetched for you for the time being

[kaipai]

Dear Deadlyking,

Thanks a loooooot for replying me twice.
I am sorry to say that the answer is D i.e. Tertiary and tertiary. So unfortunately the answer is not B.I am sorry that I forgot to quote it before.

Could you now kindly explain how the correct answere is D???
By the way what grade you scored in bio A level?
Thank u v much.

[Deadly_king]

Dear Deadlyking,

Thanks a loooooot for replying me twice.
I am sorry to say that the answer is D i.e. Tertiary and tertiary. So unfortunately the answer is not B.I am sorry that I forgot to quote it before.

Could you now kindly explain how the correct answere is D???
By the way what grade you scored in bio A level?
Thank u v much.

Okay, let's see how D turns out as the most appropriate answer

Primary structure - the amino acid sequence of the peptide chains.

Secondary structure - highly regular sub-structures (alpha helix and strands of beta sheet) which are locally defined, meaning that there can be many different secondary motifs present in one single protein molecule. (DUE TO INTERACTIONS OF THE PEPTIDE GROUPS ONLY!)

Tertiary structure - Folding due to interactions of the side groups of the different amino acids.

Quaternary structure - complex of several protein molecules or polypeptide chains, usually called protein subunits in this context, which function as part of the larger assembly or protein complex.

IN OTHER WORDS ONLY THOSE ENZYMES CONTAINING MORE THAN 1 POLYPEPTIDE CHAIN WILL HAVE QUATERNARY STRUCTURE.
EG. LYSOZYME IS A SINGLE CHAIN AND DOES NOT HAVE QUATERNARY STRUCTURE.

So for the active site, it's certain to be tertiary structure! Depending on the enzyme, it may have quaternary as well but not all enzymes have it

As for non-competitive inhibition, like I said it may bind almost anywhere! But a protein in this case an enzyme with a tertiary structure, has it's tertiary structure most exposed and weaker bonds! The primary and secondary structure are well hidden by the tertiary structure

So we can now conclude that D was the most appropriate answer

You're most welcomed

I've done Biology upto AS level and I scored A But that was two years ago

[kaipai]

Dear Deadly King,

First of all I must vigorously appreciate your efforts and knowledge that you answered with due detail and explained how the correct answer is D. Hats off to your stamina!

Just tell me how can I find the correct answer when I am in time limit during exams?
How did you prepare for AS bio exams 2 years ago and how you managed to secure an A (I am also currently taking AS bio)?

And Finally How can I use my faulty bio book (which is surprisingly endorsed) to secure Grade A at AS level? Please tell me how can I master such tricky and stamina testing questions which only brave people like you dare answer?

Thank you very very much,

My best regards for you to be most successful  in all you career,

Good bye and take care.

kai pai

[Deadly_king]

You are welcomed dude We in this forum are all ready to share our knowledge, resources and experience with  other members

Well, you should know the definition of each structure first and understand how they are maintained(I mean the bonds involved). This should be enough to help you answer these sorts of questions rapidly

As for preparation, you should read and understand all the basic principles! Your book is not defective It may lack certain notes but it's still sufficient for you to score good marks Understanding will help you answer the questions wisely!

And lastly, after you've completed the whole syllabus, then practise on past exam papers! Do as much as you can and correct them using Marking Schemes! Remember practice makes perfect

Thanks for your wishes......that was very kind of you

[kaipai]

Dear Deadly King!

Thanks a lot for replying again (not many people would do this!). Thanks a lot for encouraging me as well and for telling me that my bio book is not defective .

I want to ask another question of the same paper oct nov 2010.

Q. Which cell organelle does not contain nucleic acid?
A. Cholorplast. 
B. Golgi Apparatus
C. Lysosome
D. Ribosome.

Tell me the correct answer which is not the third letter of alphabet neither the 1st letter nor the 4th letter but the remaing of the ABCD give above. Now tell me why and how on earth someone can know that the correct answer is not A but B.???Again, sorry, my bio book not mentions this???PLZZZZZZZZZZZ explain how B is correct?
How did u prepare for bio AS from notes or from book? Tell me. U are the only one who would dare reply again, others here perhaps find my questions either too boring or too difficult. How many subjects did u take in a sitting? I am afraid taking 1 or 2 is bad?

Thank you deadly king!
Take care.

[Deadly_king]

Dear Deadly King!

Thanks a lot for replying again (not many people would do this!). Thanks a lot for encouraging me as well and for telling me that my bio book is not defective .

I want to ask another question of the same paper oct nov 2010.

Q. Which cell organelle does not contain nucleic acid?
A. Cholorplast. 
B. Golgi Apparatus
C. Lysosome
D. Ribosome.

Tell me the correct answer which is not the third letter of alphabet neither the 1st letter nor the 4th letter but the remaing of the ABCD give above. Now tell me why and how on earth someone can know that the correct answer is not A but B.???Again, sorry, my bio book not mentions this???PLZZZZZZZZZZZ explain how B is correct?
How did u prepare for bio AS from notes or from book? Tell me. U are the only one who would dare reply again, others here perhaps find my questions either too boring or too difficult. How many subjects did u take in a sitting? I am afraid taking 1 or 2 is bad?

Thank you deadly king!
Take care.

Very tricky question.......not so obvious

Anyway first you should know what exactly are Nucleic acids : They are DNA and RNA

1. Deoxyribonucleic acid (DNA) is a nucleic acid containing the genetic instructions used in the development and functioning of all known living organisms. They are found in nucleus of most cells.

2. Ribonucleic acid (RNA) is a nucleic acid which is essential for all known forms of life. They are of diverse types and may be located in many organelles. They are required for the synthesis of proteins since they code for them........meaning they carry precious information for the production of a particular protein.

Now we get back to your answers.......
All of them are organelles but they have different functions. It's their function which will help you identify the most appropriate answer here.

Function of :
1. Chloroplast : Photosynthesis
2. Golgi Apparatus : Modifies proteins
3. Ribosomes : Synthesis of proteins
4. Lysosomes : Scavengers of a cell, they eat up old unwanted organelles

So here itself we can eliminate A and C since they both carry out synthesis and where synthesis is concerned, RNA are bound to be there
There is also a type of RNA known as Ribosomal RNA founds in Ribosomes.
As for D, it engulfs all organelles which are no more in function, so it will definitely have taken in some RNA as well.

As for Golgi Apparatus, it only modifies the proteins but do NOT synthesise it That's why it is free of nucleic acids

Hope I've been able to make it clear enough for you

Well for me I got notes from my tutor plus this book itself The drawings help to understand a lot

Well I sat for Chemistry, Maths and Physics(complete A-level) and Biology and General Paper upto AS level

Others are perhaps busy with exams and all

[kaipai]

Dearest Deadly King,

Thank u v v v much. but what drawings wer u talking about. Thank u for telling me why I am replid only by u.
Tak care

[Deadly_king]

Dearest Deadly King,

Thank u v v v much. but what drawings wer u talking about. Thank u for telling me why I am replid only by u.
Tak care

Most welcomed buddy

Oh.....all the drawings in the book They help you understand the concepts better

Good Luck