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efficiency of metabolism?

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efficiency of metabolism?

Postby Erised » Sun Nov 27, 2005 7:02 pm

Hey all
I have to answe this question but I have no idea what it means. I'm assuming it's about how ATP is used to make enrgy for the cells. Do you think this is it? Because I answered this already. um.. anyhow

Efficiency of our metabolism:
Production of ATP generates heat, and this is why animals give off heat to the environment. There are three types of cellular work – mechanical (contraction of muscle cells, movement of chromosomes during mitosis), transport (pumping of substances across a membrane against their gradients), and chemical (pushing of chemical-required actions).
The three types of work are all powered by hydrolysis of ATP. A phosphate group is transferred from ATP to a molecule, and this molecule becomes phosphorylated, and undergoes change that performed work. When a phosphate group was removed from ATP, 7.3 kcal of energy was released. This means that 7.3 kcal released by 38 ATP molecules generates 227.4 kcal. So, ATP is about 40% efficient.
To restore the used ATP, a phosphate group is added to ADP. The energy for phosphorylation of ATP comes from catabolism of the cell. This is ATP cycle, and it moves very fast. It a working muscle cells, 10 million molecules are consumed and generated in less than a second. ATP drives most of the cellular work.
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Postby MrMistery » Sun Nov 27, 2005 8:34 pm

That's all fine and dandy. But what is the question you need to answer?
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Postby Erised » Sun Nov 27, 2005 8:37 pm

Well, it's not really a question.
"Summarize the efficiency of our metabolism"

I just don't know what to write in the answer! Give me a clue or something please :oops:

*This is grouped with questions about ATP and the Krebs cycle and electron transport chain.
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Postby MrMistery » Sun Nov 27, 2005 8:41 pm

Well, i guess you are the right track. Total energy converted into ATP is only 40%. But i think they also want you to write how much ATP is created into every step of cellular respiration(mention that GTP is formed in the krebs cycle, the teacher will se you understood)
By the way, what grade are you in?
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Postby Erised » Sun Nov 27, 2005 8:45 pm

I'm a freshman in college :shock: Why did you think I was in school?

I actually summarized all the 38 ATP and where they come from because there was a question about it.
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Postby cool A-level student » Mon Nov 28, 2005 2:44 pm

i think he thought you were in school because you don't know how to summarise it.

its a vital skill and you need to get ur head round it (and yes i am aware that im a year 12 student telling a freshman what to do and i don't know much about metabolism....well pratically nuthing, but still summarisin is neccasary)

if i knew enough about metab i'd help you out abit as well :)
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Postby MrMistery » Mon Nov 28, 2005 7:50 pm

Haha... Actually i did not say it becuase you don't know how to summarise things. There are some college professors that don't know how to make a decent summary.
Different countries have different educational systems, and the AP classes in the united states for example resemble more to college classes than high-school classes.

PS: I am in high-school too. 11th grade ;)
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Postby mark » Mon Nov 28, 2005 8:25 pm

metabolism is a toxic waste.


am a sophomore
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Postby MrMistery » Mon Nov 28, 2005 8:46 pm

metabolism is not toxic waste? SOME products of metabolism, like ammonia, ureea are toxic over a certin quantity. Some, like CO2 are tolerated in larger concentrations...

What is "sophomore"?
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Postby mith » Mon Nov 28, 2005 9:52 pm

second year student, no idea where that word comes from...incidentally sophomoric means childish.
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Answer?? Maybe

Postby Jennifer » Mon Nov 28, 2005 10:21 pm

They probably want you to write why cellular respiration has a low efficiency. It is becuase our bodies need heat to survive and maintain a constant body temperature. Since cellular respiration releases heat in the process, some of the heat is released in the atmosphere, which relates to an increase in universal entrophy (1st law of thermodynamics), and some of the heat maintains body temp!
Hope I helped:)[quote][/quote] :?:
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Postby baikuza » Wed Nov 30, 2005 2:22 am

yap! we need heat to keep our metabolism works right. metabolism in living thing just change the phase of energy not consumes it or produces it.
delta H in = delta H out
(^ ^)
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