AQA BIOL5 Biology Unit 5 Exam - 22nd June 2011

The book doesn't really tell us much about troponin does it?

Does anyone have the exam style question answers for unit 5 questions at the end of the book of the nelson thornes book?

The book doesn't really tell us much about troponin does it?

do we need to know about water potential control with ADH etc

anyone?

I REALLY don't unterstand sanger method and restriction mapping. can someone explain pleasseeeee;

and also what's the difference between adenovirus and retrovirus

it is just a molecule which has a calcium binding site, when calcium is there it causes the tropomysoin to move.

Not quite sure which book you mean, but all you need to know if that it holds tropomyosin in place, tropomyosin blocks the actin-mysosin binding site so the myosin globular head cannot bind = muscle contraction cannot happen.

For muscle contraction to happen, calcium ions must bind to troponin and thus induce it to change its shape, which moves tropomyosin from thr actin-myosin bindign site, so cross bridges can form, and muscle contraction can happen.

When calcium ions leave troponin, it changes back to original shape, and so tropomyosin blocks the actin-myosin binding site again, stopping muscle contraction.

any ideas for essay questions? i reckon it could be on cycles
hows everyone revising for the essay? ive done 2 but only got 15/25 on them even after doing everything my teacher said to improve ha! have to get all my marks from the exam as im bad at essays!

Both secreted by the Islets of Langerhans in the pancreas, both hormones.

Insulin secreted by beta cells in Islets, Glucagon by alpha cells in Islets.

Insulin is secreted when blood glucose concentration is too high.

Functions:

Activates enzymes for glycogenesis = converts glucose into glycogen.

Increases rate of respiration of glucose in cells

Makes cells more permeable to glucose.

Glucagon, secreted when blood glucose concentration is too low

Functions:

Activates enzymes for glycolysis = conversion of glycogen into glucose

Decreases rate of respiration of glucose

Stimulates gluconeogenesis = production of glucose from non-carbohydrates, such as amino acids for example.

Glycolysis is the first stage of respiration (glucose->pyruvate) glucagon activates glycogenolysis (glycogen->glucose) .

So you have so far 400 UMS, you need 480 for A, hence you need 80/140 UMS marks,
For A* you need 148/140 UMS hence impossible

around 120 UMS

Do we need to just be aware of Histamine and Prostoglandin? Or do we need to know what they do?

just be aware of what they do.

Histamine: Released when allergen enters body, swelling, redness incheness.
Prostoglandin: released when you are injured, increases permeability of capallieires.

just be aware of what they do.

Histamine: Released when allergen enters body, swelling, redness incheness.
Prostoglandin: released when you are injured, increases permeability of capallieires.

Is it not the other way round?