3.1 Importance of ATP

Question 1

Why is ATP adapted to it’s role

Answer 1

Inert
Pass out of mitochondria into cytoplasm
Release energy efficiently
Release energy in useable quantites - so little is wasted as heat
Easily hydrolysed to release energy 
Readily reformed by phophorylation

Question 2

Define chemiosmosis

Answer 2

The flow of protons down an electrochemical gradient, through ATP synthatase, coupled with the synthesis of ATP from ADP and a phophate ion.

Question 3

What is the pathway of electrons in chemeosmosis

Answer 3

Electrons from hydrogen atoms transfere from donor molecule to a recipient. Then a sequence of reactions transferes the electrons along the chain from one molecule to the next. Each transfere is redox. Oxidation reactions make energy availible, which is eventually used to synhesis ATP.

Question 4

What is the pathway of protons derived from hydrogen in chemiosmosis

Answer 4

Energy released by oxidation, pumps the protons across a membrane creating a concentration gradient. This is a source of potential energy. As protons flow back down the gradient through ATP synthetase. The energy release is converted to chemical energy in ATP.

Question 5

how do bacteria establish a proton gradient

Answer 5

They have no internal membrane so use the cell membrane by pumping protons out of the cell wall.

Question 6

Why are thylokoid, mitochondria and bacterial cell membranes described as sealed membranes?

Answer 6

The membranes can only let protons through jn a very controlled fashion. The have to be water tight because protons are small and can travel through water molecules.

Question 7

What is apoptosis and when does it occure

Answer 7

Apoptosis is programmed cell death and occures during embryonic development. Operates by preventing proton gradients across cell membranes from forming.

Question 8

What is DNP and when does it occure

Answer 8

Mitochondrial poison that allows electron transport but does not allow ATP synthesis. Some people have used DNP to try and loose weight. The body oxidieses facts and carbohydrates, so weight is lost, but all the energy released from those molecules is converted to heat, as no ATP can be made. The body overheats sometimes fatally.