enzymes

[Dencology]

What happen to an enzyme after a reaction takes place?

• the enzyme is degraded and recycled
• it participates in negative feedback
• it releases substrate and further catalyzes
• it is inhibited by product
• it is permanently conformed into tense state

which of the following supports the endosymbiotic theory?

• double membraned nuclei
• DNA in mitochondria separate from nuclear DNA
• Similar proteins in the nucleus and mitochondria
• Close timing of various mitotic cycles
• endocytosis

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[Zerconia2921]

What happen to an enzyme after a reaction takes place?

• the enzyme is degraded and recycled
• it participates in negative feedback
• it releases substrate and further catalyzes
• it is inhibited by product
• it is permanently conformed into tense state

Point three, it release substrate and futher catalyzes hmm I dont think it can catalyzes without a substrate so that will be wrong.

The best answer I think is it particpate in negative feedback. Point two... Am i right?

 

[Predentknight]

I would say point 3 is correct bc it releases substrate and further catalyzes other substrates, not 100 percent sure, but what is the correct answer

 

[Dencology]

i don't know what is the ans. i would pick the fourth answer choice.

 

[Mstoothlady2012]

I would say point 3 as well. Once it is done catalyzing 1 substrate, it releases it and moves on to the next one. Hmm the only example I could think of right now is hemoglobin...makes sense? or am i confused?

 

[Streetwolf]

What happen to an enzyme after a reaction takes place?

• the enzyme is degraded and recycled
• it participates in negative feedback
• it releases substrate and further catalyzes
• it is inhibited by product
• it is permanently conformed into tense state

which of the following supports the endosymbiotic theory?

• double membraned nuclei
• DNA in mitochondria separate from nuclear DNA
• Similar proteins in the nucleus and mitochondria
• Close timing of various mitotic cycles
• endocytosis

3 and 2. 100%.

 

[userah]

well if the reaction has already taken place, what is the enzyme catalyzing? there should be no more substrate if the reaction is finished no?

 

[Streetwolf]

It releases the substrate and finds another one to catalyze. There's more than 1 substrate hanging around.

 

[tinman831]

well if the reaction has already taken place, what is the enzyme catalyzing? there should be no more substrate if the reaction is finished no?

The question does not specify the conditions of one enzyme, one substrate. Don't assume anything beyond what is given. Besides, none of the other answer choices would be correct anyways.

 

[userah]

sorry one more question. can't the enzyme be deactivated by feedback inhibition of the product?

i mean the way the question is phrased, after the reaction has taken place, i would assume that the product inhibits the enzyme no? or am i missing something...

 

[Sama951]

What happen to an enzyme after a reaction takes place?

• the enzyme is degraded and recycled
• it participates in negative feedback
• it releases substrate and further catalyzes
• it is inhibited by product
• it is permanently conformed into tense state

which of the following supports the endosymbiotic theory?

• double membraned nuclei
• DNA in mitochondria separate from nuclear DNA
• Similar proteins in the nucleus and mitochondria
• Close timing of various mitotic cycles
• endocytosis

The first one is 3 because 1 doesnt always happen, 2 never happens (the product is what would do this if anything), 4 doesnt happen to every enzyme (it does happen to, say, hexokinase in glycolysis as a large amount of glucose-6-phosphate will signal hexokinase to stop catalyzing its reaction), and 5 is just pointless

The second one I'd say is 2 because it suggests that mitochondria were at one point a separate organism that, through endosymbiosis, became a vital part of a larger organism. The other ones are all just processes or whatever that different organisms may take part in to suggest they might be related or something like that, not really anything to do with endosymbiosis.

 

[dontwakeme]

Yeah it's definitely 3 and 2, respectively.

 

[Sama951]

Actually you know what, I'm not even sure any more... It says "releases SUBSTRATE and continues to catalyze"... but it doesnt... it releases PRODUCT and continues to catalyze. I'm kinda thinking now that it's the "is inhibited by product" one... I remember on my biochemistry final we had to explain how a large amount of oxaloacetate would cause a build up of malate in the TCA cycle and the answer was basically Le Chatelier's principle... So yeah that question sucks all of a sudden (to me at least but maybe I'm thinking too much )

 

[Streetwolf]

I see where you're coming from but I think you're thinking too much about it. The problem could have been better worded to say 'product'. None of the other 4 answers make sense. They either don't happen or don't ALWAYS happen.