Enzymes are globular proteins that catalyze 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.

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Do the enzymes and compounds in saliva help with stain removal?

Does spitting on stains help with removal? Saliva is high in amylase that should help with the breakdown of protein rich stains like blood and semen. It also contains antimicrobial enzymes and ...
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22 views

How is Glycophorin A and straphylococcal related to Escherichia coli and what does readily purified mean in this context?

I am reviewing the paper "Glycophorin A Dimerization Is Driven by Specific Interactions between Transmembrane Alpha-Helices." There is a statement in the abstract which I don't understand: "The ...
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47 views

Which enzymes degrade dynorphins and what drugs inhibit these enzymes?

Which enzymes degrade dynorphins and what drugs are there available to inhibit said enzymes?
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27 views

Nagalase testing any good?

Is Nagalase testing good to detect if something is wrong in the body (ex: cancer)? The next problem I assume would be to know what/where the problem is. To put it an other way: If I understand ...
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1answer
23 views

Is NADPH unstable in UV light?

I am working on an enzyme activity assay using NADPH as a cofactor. The MSDS for NADPH Tetrasodium Salt, tells to store it in a place away from heat and light. Does this include UV light or just ...
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124 views

Enzyme Assay - pectinase

During assaying an enzyme at high temperature, the substrate (Pectin) is degraded by the high temperature rather than by enzyme, so, how can I minimize degradation of the substrate by the temperature? ...
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50 views

How is the subunit molecular weight different from the native molecular weight?

I noticed that the native molecular weight for an enzyme is different from its subunit molecular weight. Why are they different? Aren't the genes needed to express the enzyme the same in the native ...
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1answer
25 views

Proline Iminopeptidase v Proline Aminopeptidase

We're an undergraduate independent research team and we are having trouble purchasing commercial proline iminopeptidase as it is unavailable on Sigma Aldrich and very expensive on other websites. We ...
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150 views

The effect on the efficacy and potency of a non-competetive antagonist binding to the active site of the receptor (dose-response curve)

According to the book "Principles of Pharmacology: The Pathophysiologic Basis of Drug Therapy" by Golan et al, non-competetive antagonists can bind to both the allosteric site and the active site. I ...
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329 views

Does enzyme Km comparisons make sense?

I have encountered comparisons of the Michaelis-menton constant (Km) a few times. Generally speaking if Km of an enzyme is higher, then it's affinity to its substrate is lower. How does this make ...
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52 views

Do non-enzyme catalysed reaction pathways exist?

Can their be a kind of chemical reaction pathway in a cell, that is catalyzed or regulated but NOT necessarily by enzymes? I could not find anything on Google. I have almost no background in biology, ...
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41 views

Applying kiwis on gelatin

Kiwis have the enzyme actinidain. This enzyme will break the peptide bonds from the gelatin. Making gelatin with raw kiwis will not work, because the peptide bonds in the gelatin will be broken down. ...
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510 views

Grapefruits and CYP3A4

Grapefruit juice contains furanocoumarins, which irreversibly inhibit CYP3A4. For this reason, when one is taking certain medications it is necessary to not eat grapefruits because the inhibition of ...
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51 views

How can human infants express chymosin with only a pseudogene at their disposal?

I read on the Wikipedia article about Chymosin http://en.m.wikipedia.org/wiki/Chymosin It stated that chymosin is produced by gastric chief cell in human infants. But it also stated that human only ...
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22 views

Where does the oxygen and water produced from the decomposition of hydrogen peroxide by catalase enzyme go?

How are they disposed of by the body, or are they disposed of at all? Since our body needs water and oxygen anyway, I'm speculating that these "waste product" will be reused/recycled by the body in ...
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70 views

Medical Uses of toxic venom

One interesting thing I recently learned is that venom has medical uses that can actually save lives! But from what I see so far this either applies to venoms from creatures that are not fatal to ...
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1k views

How is Taq polymerase produced?

I've seen Taq polymerase being marketed as either "native" or "recombinant". I understand that the recombinant version is produced by specially modified Escherichia coli strains that have the gene for ...
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1answer
37 views

Hydrogen peroxide decomposition and catalase uses [closed]

All google searches have simply returned more info on catalase. I'm looking for a catalyst that isn't found inside living organisms which can break down H2O2. Looking for any resources to look at, or ...
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83 views

Is there a DNA analogue to ribozymes? [duplicate]

If not, is it impossible for DNA to have enzymatic activity?
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86 views

Enzymatic error rate

I am aware that each enzyme generate a certain amount of misproducts. This is well documented, for example, for the DNA polymerase. I am interested in enzyme involved in biochemical processes, so for ...
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15 views

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 ...
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55 views

Mode of Enzymatic Inhibition via R-Allele

The photo above shows the effects of the R allele of the pea shape gene on the synthesis of an enzyme that converts unbranched starch into branched starch. The r allele of this gene determines an ...
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110 views

How does salinity affect the bonds of an enzyme?

According to my textbook, "Too much or too little salt can interfere with the hydrogen bonds that hold an enzyme in its three-dimensional shape". I know that NaCl is held together by an ionic bond, ...
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67 views

How do catalase and other antioxidants neutralize free radicals?

In learning about how cofactors are essential to proper enzyme function, my textbook mentioned catalase and its relation to the human body. According to my textbook, catalase is similar to hemoglobin ...
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59 views

Substrate specificities of GPPS, FPPS and GGPPS (isoprenoid biosynthesis enzymes)

I have some questions related to isoprenoid synthesis enzymes. Does Geranylgeranyl pyrophosphate synthase (GGPPS) contribute in Geranyl-Pyrophosphate (GPP), Farnesyl pyrophosphate (FPP) and ...
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2answers
515 views

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 ...
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1answer
689 views

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 ...
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2answers
713 views

Does “Garbage Enzyme cleaner” contain cleaning enzymes?

There are many recipes which call for using fruit peel fermentation process to make a concentrated enzyme cleaner solution, some variations call to add bakers yeast. So the question arises that does ...
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43 views

Alkaline Phosphatase

What is the predominant purpose of Alkaline Phosphatase in skeletal muscle fibers and liver cells. I know that it is a hydrolase enzyme that speeds up the degredation of proteins, lipids, starch and ...
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1answer
227 views

Is the activity of enzymes in the human body affected by the outer temperature?

I have to do a research about the enzymes in the human body and the things that affect them. I know that the body temperature affects the activity of enzyemes but I'd like to know if the outer ...
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339 views

How do the pharmacodynamics of the NSAIDs differ and are there “resistant” COX phenotypes?

I know that the non-steroidal anti-inflammatory drugs (e.g., aspirin, ibuprofen, naproxen) affect the enzymes cyclooxygenase (types I and II). Is there any difference in the degree to which these ...
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629 views

What is a catalytic domain of an enzyme?

Is this another name for the active site of an enzyme? What does the structure of the catalytic domain of an enzyme look like?
4
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57 views

Correlating beta-lactamase expression to absorbance

When penicillin-resistant bacteria are grown in liquid culture media, β-lactamase is secreted into the medium. The supernatant of such a medium can be assayed for β-lactamase activity. ...
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2answers
93 views

What does it mean to perform in vitro experiments with mutant bacteria?

I came across the following sentence while reading the paper: Nanchen, Annik, et al. "Cyclic AMP-dependent catabolite repression is the dominant control mechanism of metabolic fluxes under glucose ...
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123 views

What is the expected effect of pH on the activity of a fungal pectinase?

I am working on an enzyme assay for a fungal pectinase.I assayed the enzyme in different buffers from pH 1-12.5 However,the enzyme has good activities starting from pH1-10.5. Is it possible to have ...
2
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1answer
88 views

Pectinase Enzyme Assay

I am working on pectinase enzyme assay. I incubated 900 ul of substrate for 10 minutes in the water bath, followed by adding 2ml of DNSA reagent, then 100ul of enzyme extract added finally i read the ...
4
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1answer
417 views

DpnI over-digestion

We have a long protocol that we are optimizing that includes DpnI digestion of a PCR product (to remove any of the template DNA if it's methylated, and while we're not certain in the blind tests, ...
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1answer
48 views

Mechanism of DNA gyrase inhibitor

Why DNA gyrase inhibitor, such as Nalidixic acid and Norfloxacin, do not stop gyrase from cutting DNA helix but only prevent them from decatenation replicating DNA?
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42 views

bacterial cell wall degradation in humans

can human degrade the D-amino acid present in bacterial cell wall, I'm confused about it i have read somewhere that human can do so.If yes than why we need antibiotic to kill bacteria???If it is not ...
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45 views

How long does it take for a cell to synthesize an enzyme?

Where can I find data regarding the times distinct cells take to synthesize distinct enzymes?
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250 views

What happen's to a virus's capsid after it injects its genetic material into the host cell?

After a virus (one of the varieties which infects the cell via injection and not endocytosis) injects its genetic material into the host cell, what happens to its protein coat? I would guess that it ...
2
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1answer
85 views

What does “thermodynamic equilibrium” mean for an enzyme-substrate complex?

From Fersht, Enzyme Structure and Mechanism p. 87: The Michaelis-Menten mechanism assumes that the enzyme-substrate complex is in thermodynamic equilibrium with free enzyme and substrate. In ...
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63 views

Enzyme kinetics [closed]

I can't understand how to study enzyme kinetics. Say I have a lipase and want to study the kinetics of this lipase using a fluorogenic substrate, how would I do this? From what I understand I would ...
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1answer
61 views

Curious about Brazzein

What is in compound "Brazzein" that it makes it 2000 times more sweeter than sugar? Can anyone please explain the science behind it?
2
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1answer
114 views

What are the Gateway clonase enzymes?

The Gateway cloning system utilizes what Life Technologies refers to as "Clonase enzyme mix" to catalyze the BP and LR reactions. What is in this enzyme mix? Is there a sequence for them?
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3answers
346 views

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 ...
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28 views

How is bacterial plasma membrane made?

Eukaryotes have ER which manufactures plasma membrane of cells. How is prokaryotic plasma membrane made ? What is the pathway and which enzymes are involved ?
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3answers
1k views

The effect of pH on enzymes

I am currently studying biology and have a question. I know that as pH increases, enzyme activity increase until the enzyme's optimum pH is reached. However, I would like to know why as pH increases ...
3
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1answer
81 views

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 ...
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34 views

Telomerase in tetrahymena

In this amazing video, at 26:03 we see this image We now know that the telomerase contains a sequence complementary to the telomere sequence and so is able to do what it is capable of doing in this ...