BIOL4 Biology Unit 4 Exam - 13th June 2011

It's about realising they are testing your knowledge of aerobic and anaerobic respiration. Before being moved the apple is respiring almost entirely aerobically. During this, for every glucose molecule, 6 molecules of CO2 are produced. But equally a lot of ATP molecules are produced (36, 38 or 40 depending on how you work out your net production, assuming full efficiency, which is unrealistic, but not really to be worried about in this question). What matter is that we get around 6 ATP per CO2 molecule produced. After being moved to the nitrogen atmosphere, so no oxygen is present, the apple respires anaerobically so we get 2 CO2 and a net production of 2 ATP per glucose. This means we only get 1 ATP per CO2. Now if we assume the apple is using up ATP in metabolic processes etc at the same rate in both atmospheres then for every 6 CO2 molecules produced in anaerobic conditions only one is produced in aerobic conditions. As a result the rate of CO2 production is higher in the nitrogen atmosphere, despite the fact this might intuitively appear wrong.

this may sound stupid so sorry lol - but during which process is CO2 produced during anaerobic respiration?? Is it the bacteria (yeast) that convert pyruvate into ethanol for plants? do they respire it, but if so how?

I am so ****ing worried about tomorrow. I know all the content but the questions are going to screw me over.

what is the role of cytokines??

Cytokines are released from t'helper cells to alert t'killer cells to kill infected cells and cause b -cells to multiply and differentiate into plasma cells and so on....

Cytokines are released from t'helper cells to alert t'killer cells to kill infected cells and cause b -cells to multiply and differentiate into plasma cells and so on....

question for you :

It is about energy transfer from sunlight to a bullock which feeds on grass....

amount of energy in sunlight = 1046700 kj m^-2 per year.
of this the grass is 13.1% efficient.
of this the bullock uses 4.1% of its energy for new tissue.

the energy stored in the new tissue of the bullock each year is 125 kj m^-2 ....

calculate the amount of energy trapped each year by each square metre of grass.... show your working. (2 marks) ...

Guys, could someone please help me on this question in the Nelson Thornes textbook. I don't understand it at all and it has come up before on previous papers. Its page 57, and the application box titled 'Sequencing the chain'.
+rep. Thanks

Is the answer: Energy stored by grass is 3049 kJm-2

Hi i had a problem with this before my teacher went through it well basically yuou have to work out where the inhibitor is working because the electron carriers after cannot be reduced so will stay oxidised as the electrons cannot be passed on.
Therefore C is first as it is reduced with all three inhibitors, then A and so on?
does that help?
sorry if im a bit complex with my explaining... if you draw the chain out and mark on where each inhibitor is acting it might help better.

no... i thought this at first. did you just do 125/4.1 x 100 = 3049 ..... cos thats what i did.

apparently the answer is 23,275... but i don't know how you get there? apparently the markscheme uses the equationd 125/4.1 and 125/13.1 ???