Biology Paper 1

[[Spy]]

Hey Guys

So last paper in Bio AS, paper 2 was dam easy and so was paper 3, so i think the paper is going to be a killer :/

plus look at physics paper 1 was relatively very hard, so yeah god be with us, but since physics was full of repeated questions then so should bio so focus on past papers


any questions lets post them here and anyone predicting anything share it with us

good luck all

ill start with the questions myself, in one of the papers it asked

What level of organization is Responsible For the globular shape of enzymes?

- Primary
- Secondary
- Tertiary
- Quaternary

it should be quaternary but its tertiary how :S

[XaM!!]

its tertiary...
primary refers to sequence to amino acids.
secondary refers twisting of chains into alpha helix n b-pleated
tertiary refrs to bending of chains to form GLOBULAR or fibrous proteins... n lastly
quaterny refers to prosthetic group(like sulphur proteins or iron in haemoglobin)

[Gaz]

Correction: quaternary does not necessarily have to have a prosthetic group. quaternary structure is the arrangement of multiple folded protein or coiling protein molecules in a multi-subunit complex, i.e: more than one polypeptide chains. eg: myoglobin has one folded chain hence it has a tertiary structure. haemoglobin has 4 chains, hence a quaternary str.

[XaM!!]

Quaternary always have a prosthetic group. like myoglobin n haemoglobin have iron as prosthetic group.

[[Spy]]

no in my book it specifically says quaternary is for globular. :S
well it doesnt specicially say that but globular proteins part is under quaternary organization, but thanks

[cashem'up]

yea but too be more specific tertiary is when there is only one polypeptide chain and in quartenary more than one , and yes tertiary structure is a part of the quartenary structure therefore it is possible that like haemoglobin  they mention such as globular....

[unknown 101]

13. HIV-1 protease is an enzyme produced by the HIV virus.
Two identical chains of 99 amino acids form the enzyme. In each chain, amino acids 25, 26 and
27 in the sequence form part of the active site.

Which orders of protein structure control the shape of the active site?

A primary, secondary, tertiary and quaternary
B primary, secondary and tertiary only
C primary and quaternary only
D quaternary only

why is the answer A?

[unknown 101]

Which of the following are increasing the spread of malaria?
          1 continued migration of people due to war and civil unrest
          2 increasing carbon dioxide levels causing global warming
          3 increasing resistance to antibiotics and other drugs

A  1 and 2 only
B  1 and 3 only
C  2 and 3 only
D  1, 2 and 3

the answer is D, but how does increasing carbon dioxide levels cause an increased spread of malaria?
is it because it produces an optimum temp for the female anopheles mosquito eggs to hatch?? :S

[AN10]

it is because mosquitoes prefer warm temperature which is required by malarial parasite to complete their growth cycle.

[unknown 101]

it is because mosquitoes prefer warm temperature which is required by malarial parasite to complete their growth cycle.

Thanks 

[XaM!!]

@unknown i think its only primary n quaternary... buh m not sure.

[nid404]

What level of organization is Responsible For the globular shape of enzymes?

- Primary
- Secondary
- Tertiary
- Quaternary

it should be quaternary but its tertiary how :S

It's not quaternary. quaternary structure arises when there is more than one polypeptide chain. The very first globular,3-d structure is gotten by the tertiary structure. In proteins with the highest order of structure being tertiary are also globular, e.g Myoglobin.

[nid404]

13. HIV-1 protease is an enzyme produced by the HIV virus.
Two identical chains of 99 amino acids form the enzyme. In each chain, amino acids 25, 26 and
27 in the sequence form part of the active site.

Which orders of protein structure control the shape of the active site?

A primary, secondary, tertiary and quaternary
B primary, secondary and tertiary only
C primary and quaternary only
D quaternary only

why is the answer A?

The sequence of amino acids is the primary structure. When the primary structure is in itself altered, the following structures will also suffer a setback. If the sequence of amino acids in the primary structure is hydrophilic instead of phobic, then the secondary and tertiary structure will also be different, the folding of the chain will be different, the final shape will be different. Hence if a change happens in the primary structure, the following structures will also change

[unknown 101]

The sequence of amino acids is the primary structure. When the primary structure is in itself altered, the following structures will also suffer a setback. If the sequence of amino acids in the primary structure is hydrophilic instead of phobic, then the secondary and tertiary structure will also be different, the folding of the chain will be different, the final shape will be different. Hence if a change happens in the primary structure, the following structures will also change

Thanks  
i didnt get the question cuz it looked retarded, Thanks again

[nid404]

not a problem