AQA Biology Unit 1 January A-S 2012 *EXAM FINISHED*

1)active transport requires metabolic energy in the form of ATP and active transport is against a concentration gradient
2)form lysosomes and transport modify and store lipids
3)consists of folded inner membranes called cristae which increase surface area and matrix is where chemical reactions take place?
4)is it cos of different strains of the pathogen???
5)smoking and high bood pressure

some of them might be wrong could you please correct me if they are

1) Thats correct.
2) Number 2, yes it forms lysosomes, HOWEVER, it doesnt modity, and store lipids aha, thats the smooth endoplasmic reticulum. It basically packages and modifes proteins, by adding carbohydrates, then pinches it off from the cisternae into vesicles etc.
3) Yes.
4) No. booster --> more antigen --> more memory cells --> faster production of antibodies
5) yes

1) There are muscles, which contract, churn up the food.. etc..? ' \:
2) I dunno? omg :L They increase SA but food is undigested in the stomach so cannot be absorbed.
3) o_O R group, amino group, carboxyl group and hydrogen group
5) Releases toxic proteins, binds to the carbohydrate receptors on the cell surface membrane, causes channel/carrier proteins to be opened up --> releases chloride ions into the lumen of the intestine, lowers wp, so water enters from cells via osmosis
6) Phagocytosis I think - phagocyte, attracted to the pathogen via chemical attractants/ recognises the pathogen as foreign. It engulfs it, forming a phagosome/vesicle. Lysosomes fuse with it, and empty lytic enzymes into the vacuole, hydrolysing it.

One question for all of you..

How do enzymes act as catalysts?

1) Diffusion gradient x surface area
Diffusion pathway 2/2
2) Needs to send blood to the rest of the body so has muscular walls. 0/2 - needed to say thicker muscular walls and then make a comparison to the right ventricle
3) Add ethanol and solution goes cloudy if it is a lipid? 1/2 - ms says to not accept cloudy, has to be milky/white.
4) Minimum amount of energy required for a reaction to take place. 1/1
5) Electron microscope has a shorter wavelength so has a higher resolving power? 2/2, 2 people have said higher resolving power so im going to presume its right - sorry thats not exctly the best way to mark hahah

1) surface area x difference in concentration/ thickness of exchange surfaces 2/2
2)left ventricle has a thicker, more muscular wall so ventricle contracts more forcefully thus creating higher pressure 1/2 fussy mark scheme, needed to directly compare to right ventricle
3)emulsion test? - add ethanol to the sample and shake, then add water and a cloudy white colour suggests a the presence of a lipid 2/2
4)mimimum energy needed to kickstart a chemical reaction 1/1 - going to say its right but kickstart seems like one of those words they might be like "eh, deny", so just sa something like minimum energy required. though i may be wrong about kickstarts.
5)electron microscope has higher resolving power and higer magnification, electrons have shorter wavelength?? 2/2

these might be wrong so please correct me

One question for all of you..

How do enzymes act as catalysts?

They lower the activation energy.

What's the difference between a channel protein and a carrier protein? I thought they were the same

The do not take part in the reaction themselves??

Through the formation of enzyme substrate complexes
(from the spec aha)

Whats do you guys think will be the two 5 markers?

They lower the activation energy.

lol beat me to it

Whats do you guys think will be the two 5 markers?

x