OCR Biology F212 Revision [3rd June 2013] (Now Closed)

What you said is right... might be worth mentioning the heavy and light polypeptide chains and the disulphide bridges that hold the structure together...

A coenzyme is an organic non protein molecule that binds to the active site of an enzyme at just about the same time as the substrate molecule...
In many cases a coenzyme is essential for the reaction to take place...
Thats all i've got

What are the disadvantages of Ex Situ conservation?

guys i keep getting 50/100 in my papers i cant get it past 60 and im really stressing!
any advice?

ALSO if anyone please could help, what are the differences between starch, glucose, amylopectin, amylose etc, like the ocr textbook says one thing and the cgp says another!

Oh thank you
And yes...they can take part in the chemical reaction but they're used to transport chemicals to the enzyme but unlike substrate molecules, they are recycled back out to take part in the reaction again And they can contribute to the shape of the enzyme too

Disadvantages of ex situ...which is in captivity
- The organisms are unable to experience life in the wild
- If a natural disaster takes place, almost all organisms will be at risk
- Spaces are limitied...too small
- When released, they'll be too adapted to their ex situ environment and won't breed with other wild animals

Describe 4 primary defences in humans and explain their importance

What are the marking points regarding a general 'how are fossils used to prove the theory of evolution?'

What are the marking points regarding a general 'how are fossils used to prove the theory of evolution?'

guys i keep getting 50/100 in my papers i cant get it past 60 and im really stressing!
any advice?

ALSO if anyone please could help, what are the differences between starch, glucose, amylopectin, amylose etc, like the ocr textbook says one thing and the cgp says another!

-Fossils show changes over time
-Fossils can be dates
-You can use fossils to show intermediate forms
-The oldest fossils contain the most simple organisms
-Some fossils contain traces of DNA

Have you done all the past papers? If yes I'd say circle the bits you found particularly difficult and write some last minute flash cards of longer answers (basically learn the markscheme for a few) because knowing how to answer then could bag you 12 ish marks in the paper assuming there's a couple of long ones. If no look at the mark schemes for the long ones.

Alsooo I always go over the specification the night before highlighting annoying I don't want there to be a question on and then looking over it- finding any q's in the past. Papers.

Lol dunno if it will pay off!

Anyway:
STARCH is a storage polysaccharide in plants. It's made up of AMYLOSE and AMYLOPECTIN. It's insoluble so does not affect the water potential of a cell and forms granules.

AMYLOSE is made up of alpha glucose. It forms a helical structure. It is a straight chained molecule of 1-6 glycosidic bonds. It is insoluble.

AMYLOPECTIN is also made up of alpha glucose. But it is a branched molecule, with 1-6 glycosidic bonds and 1-4 glycosidic bonds. Apparently it's soluble- according to Wikipedia and also apparently it's 70% of starch so I'm not really sure why starch is insoluble all together, but hey I'm just gonna accept it- anyone?

GLYCOGEN is the animal equivalent of starch- store of glucose. Similar molecule to amylopectin it is a highly branched alpha glucose polysaccharide with 1-6 and 1-4 glycosidic bonds. When talking about function remember its insoluble, doesn't affect water potential of cell and glucose monomers can easily be broken off by hydrolysis reactions and respired to release energy. Also it's a dense energy store.
X

What does ex situ mean? How would you define it?

Yes, could mention about loss of genetic variation due to there not being lots of individuals in captivity and the fact that inbreeding through generations will only reduce the gene pool further leaving the captive population susceptible to the same diseases etc.

Skin - acts as a physical barrier to bacteria
Stomach Acid - Kills any bacteria that may be travelling through digestive system
Mucous Membranes - In the nose and in lungs (mucous produced by goblet cells) traps bacteria so that it cannot travel any further into body
Tear Fluid - contains antibodies which will attach to the pathogens antigens in an attempt to neutralise and alert the rest of the immune system

Describe the transmittion of malaria

thankyou

Have you done all the past papers? If yes I'd say circle the bits you found particularly difficult and write some last minute flash cards of longer answers (basically learn the markscheme for a few) because knowing how to answer then could bag you 12 ish marks in the paper assuming there's a couple of long ones. If no look at the mark schemes for the long ones.

Alsooo I always go over the specification the night before highlighting annoying I don't want there to be a question on and then looking over it- finding any q's in the past. Papers.

Lol dunno if it will pay off!

Anyway:
STARCH is a storage polysaccharide in plants. It's made up of AMYLOSE and AMYLOPECTIN. It's insoluble so does not affect the water potential of a cell and forms granules.

AMYLOSE is made up of alpha glucose. It forms a helical structure. It is a straight chained molecule of 1-6 glycosidic bonds. It is insoluble.

AMYLOPECTIN is also made up of alpha glucose. But it is a branched molecule, with 1-6 glycosidic bonds and 1-4 glycosidic bonds. Apparently it's soluble- according to Wikipedia and also apparently it's 70% of starch so I'm not really sure why starch is insoluble all together, but hey I'm just gonna accept it- anyone?

GLYCOGEN is the animal equivalent of starch- store of glucose. Similar molecule to amylopectin it is a highly branched alpha glucose polysaccharide with 1-6 and 1-4 glycosidic bonds. When talking about function remember its insoluble, doesn't affect water potential of cell and glucose monomers can easily be broken off by hydrolysis reactions and respired to release energy. Also it's a dense energy store.
X

Correct

Transmission of malaria;
Female anopheles injects contents of infected salivary gland into human which has Plasmodium (the parasite).
This enters the humans red blood cell and/or liver cells where it reproduces and eventually bursts the cell to release it around the body/blood stream
Symptoms occur
Another mosquito feeds on the human, sucking out the infected blood for further transmission elsewhere thus continuing the cycle

Difference between glucose and amylose

Correct, be sure to mention the stages of development for the parasite (e.g. gametes in mosquitos stomach, zygote forms and when it develops to its infection stage moves to salivary glands)

Glucose: Monosacharide, has alpha and beta forms, (alpha OH below carbon ring, beta OH above carbon ring)

Amylose: Polysacharide, alpha glucose monomers joined by condensation (water eliminated) reactions forming glycosidic bonds, helical structure forms due to 1,4 glycosidic bonds

What does ex situ mean? How would you define it?