Question

HELP PLZ!!!!

When an individual stops breathing, brain cells die very quickly, but the cells in the heart are able to survive for longer. Which conclusion is best supported by these facts?

Brain cells are more specialized than muscle cells and require more oxygen.

Unlike heart cells, brain cells do not use ATP as their energy-storing molecule.

Unlike brain cells, heart cells can produce small amounts of ATP by going through fermentation.

Blood does not travel to the brain unless it first goes to the heart.

Answer 1

are u sure??

Answer 2

I am not sure what it should be, but I don't think that is the right one really

Answer 3

are you sure???

Answer 4

thank you very much

Answer 5

so what do brain cells use as their energy source? just electric potential?

Answer 6

idk :/

Answer 7

For an energy source, brain cells (and all other neurons) use glucose and they use a heck of a lot of it.

Neurons convert the energy stored in the glucose into energy stored in ATP via the usual glycolysis-TCA cycle-electron transport process. Then they use that energy stored in ATP to create concentration and electrical gradients by pumping small ions across the membrane. These pumps are proteins which break that the unstable, high energy bond which holds the third phosphate group to the rest of the molecule and use the energy released to push ions back and forth against their gradients.

Then, when stimulated, channel proteins in the cell membrane open. All the ions flow through the channels down their concentration gradients; the membrane depolarises *locally* and, if the depolarisation is strong enough, it propagates depolarisation throughout the rest of the neuron.

The bottom line is that the energy used by brain cells (and for that matter pretty much every other kind of cell) comes from glucose. Brain cells use that energy to create and maintain these very energetically expensive electrochemical gradients - essentially they convert chemical energy to potential energy stored in a concentration gradient. Then they use this to think and do all the stuff I expect my brain cells to do as I answer this question. Hope I didn't belabour the point.

Answer 8

That above was to clarify Turing's question.

It should be clear from that discussion that brain cells do actually use ATP as a high energy intermediate, so the answer given is not right. Think about the enormous amount of energy which goes into those electrochemical gradients, think about all the ATP needed to power that, and think about all the *oxidative* phosphorylation the brain needs to convert the energy stored in glucose to energy stored in ATP and you have the answer.

Answer 9

Thank you @blues for the thorough explanation. I didn't think that there were any cells in the body that do not use ATP in some way for an energy source, but I wasn't sure. You certainly did not belabor the point; these things are subtle and require deep explanations in my opinion.