Biology Stack Exchange
Biology Stack Exchange

Questions tagged [enzymes]

Enzymes are globular proteins that catalyse a biochemical reaction, increasing the overall rate by reducing activation energy. Most chemical reactions in a cell need enzymes in order to occur at rates sufficient to sustain life.

Questions should generally be on the biological action of enzymes, rather than on the chemistry of their action. Relevant tags may include .

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Are there enzymes for every given reaction?

This is a question that's been bugging me, and I haven't been able to find a definite answer anywhere. We know there are thousands of enzymes (proteins, let's ignore catalytic RNA for now) that catalyze many different reactions, and they do this…
DankMemes
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Origin of enzyme names

Sometimes I get confused about why this or that enzyme was named in this or that particular way. 1) TCA: Why was not isocitrate dehydrogenase named isocitrate decarboxylase? Wouldn't it have been at least as accurate to name the enzyme in question…
Teiko Abe
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What is the difference between a phosphotransferase, a phosphatase, a phosphorylase and a kinase?

I've looked in several sources, but I'm still confused. This is what I have so far: A phosphotransferase catalyzes the addition of a phosphate group. A kinase is a type of phosphotransferase that transfers a phosphate group from ATP to a…
nachocab
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Is it possible to repopulate lactase in the stomach?

Possible Duplicate: Can an adult without genetic lactase persistence still develop a tolerance for dairy foods? In my younger years, I don't seem to have a problem drinking milk. Nowadays, when I drink milk, I keep farting away. After searching…
chuacw
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What does "kcal/mol" mean when speaking of enzyme catalysis?

After thinking about it, I'm confused by what the reaction barrier of an enzyme actually means. Imagine a reactor containing enzyme and substrate. If the enzyme in the reactor has a reaction barrier of 15 kcal/mol, a) then when 1 mole of product…
TMOTTM
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sodium chloride and amylase activity

So, I did an experiment on the effect of sodium chloride on amylase. and I found out the higher the concentration, the slower the activity. Therefore, is it valid to make the assumption that when we consume food with starch and high salt…
luluja
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How to inactivate trypsin permanently by boiling?

I have to perform a hydrolysis of BSA with the enzyme trypsin. As a control I want to inactivate the trypsin enzyme. Can I inactivate it permanently by boiling (100oC) for 10 minutes, or does it it require 1 hour of boiling? After inactivation, I…
kt123
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Literature about industrial enzyme application

Can someone point me out to literature (reviews or better workbooks) describing industrial chemical reactions catalysed by enzymes? What I'm most interested in are case studies of how the output of a reaction on a big scale is optimized with respect…
TMOTTM
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Why do some enzymes have giant structures around the active site?

As a part of my inorganic chem. course (it's a required course at my college), we have a module called Introduction to Bioinorganic Chemistry. There, the prof. showed examples of enzymes like Cytochrome P450 and the drug erythromycin, and circled…
wermos
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How can RNAse degrade any RNA?

Every RNA has an unique sequence. Since RNAse is an enzyme and substrates react to its active site in a lock-key mechanism, how is RNAse able to degrade any kind of RNA?
Lasya T
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Screening Enzymes?

I wish to obtain a list of all known enzymes and then get rid of the ones that use cofactors, the ones that use ATP, and a few others. What is the easiest way to do this?
Dale
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Are the proteolytic enzymes in syconiums and nettles identical to those in rennet?

I would like to compare rennet capability under various conditions. The issue is, I don't want to use calf rennet, but I can't figure out if nettle and syconium, which also coagulate milk, contain regular rennet or other enzyme? If so, what is its…
Catherine
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Are there enzymes found in nature or the man made world that can help break down metals?

The title says it all. Do natural or human engineered enzymes exist that can speed up the break down kitchen utensils, aluminum cans, wires, etc. into small particles or powders? To be clear I am not talking about chemical transformation (e.g. iron…
max
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Function of coenzymes: do they act as substrate shuttles?

My biochemistry textbook, "Harper's Illustrated Biochemistry", states: Coenzymes serve as recyclable shuttles that transport many substrates from one point within the cell to another. The function of these shuttles is twofold. First, they stabilize…
Lakshya Kumar Singh
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Could removing non-functional parts of coenzymes improve enzyme function?

As pointed out here, many important co-enzymes (essential enzyme cofactors) such such acetyl-CoA and vitamin B12 contain nucleotide portions that do not function in the enzyme catalysis. They have been suggested to be relics of the RNA world, so it…
Count Iblis
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