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.

learn more… | top users | synonyms

3
votes
1answer
504 views

Questions regarding ELISA

I have recently peformed an ELISA (Enzyme-linked immunosorbent assay), but I still have some questions, let me first outline what I did: We had a number (20) of tubes containing fake 'bodily fluids' ...
3
votes
1answer
50 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. ...
3
votes
1answer
90 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 ...
3
votes
1answer
49 views

Do we actually know the molecular dynamics of any enzyme?

That is right, is there a limitation, say Heisenberg's uncertainty principle or something that limits our understanding of machinery of enzymes at atomic level? Can we know how do they actually work? ...
3
votes
3answers
36 views

Is there a database providing information about optimum temperature and inactive temperature of enzymes?

I want to know optimum and inactive temperature of some enzyme, but I can't find these information in NCBI, wiki or UniProt. So I want to know if there are some database which provide these ...
3
votes
1answer
233 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 ...
3
votes
1answer
399 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 ...
3
votes
1answer
150 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? ...
3
votes
1answer
48 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 ...
3
votes
1answer
63 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?
3
votes
2answers
398 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 ...
3
votes
0answers
41 views

Adenosine metabolism

Are adenosine or its catabolites increased in inflamed airways? How can I assess this? I am trying to use inhibitors for adenosine deaminase, xanthine oxidase, and purine nucleoside phosphorylase, but ...
3
votes
0answers
35 views

Are there any enzymes synthesised by humans that specifically catalyse the hydrolysis of non-cyclic Imides?

Imides or dicarbonyl amides are an interesting class of compounds that includes the pharmaceuticals thalidomide, aniracetam and a few other drugs. These compounds, however, are cyclic and I'm ...
2
votes
1answer
863 views

Making the sense of enzyme Km comparisons

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 ...
2
votes
2answers
137 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 ...
2
votes
1answer
160 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?
2
votes
1answer
102 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 ...
2
votes
1answer
3k 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 ...
2
votes
1answer
116 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 ...
2
votes
2answers
276 views

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 ...
2
votes
1answer
552 views

How to calculate or know by experiment the entropy of enzymes or protein?

How do you calculate or experimentally determine the entropy of enzymes or protein? In particular, I am interested in Boltzmann and conformational entropy, and Gibbs free energy. Any references are ...
2
votes
2answers
15 views

Affinity Column of membrane bound receptors

I understand affinity columns can be used to study the ligand/enzyme affinity. But is an affinity column able to be used for membrane bound receptors? I
2
votes
1answer
95 views

Dwell time equations for ATP-sythase?

I have read that every 120 degree rotation of the F1 complex of ATP-synthase can be split into a 30 degree rotation and a 90 degree rotation. In between these two are dwell times, the one before the ...
2
votes
1answer
173 views

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 ...
2
votes
1answer
37 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 ...
2
votes
1answer
19 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 ...
2
votes
1answer
100 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 ...
2
votes
1answer
42 views

Activity of glucokinase

From Solomon et al, 2013 ACC Synthetic biology and from this video : Here, there are 2 competing reactions for glucose - one with glk as enzyme and other with gdh as enzyme. In the graph, y axis ...
2
votes
1answer
87 views

Determining sequence of oligoribonucleotide

Oligoribonucleotide X was treated with phosphatase (for removal of 3' and 5' - terminal phosphates), then with RNAase T1, which cleaves all phosphodiester bonds located in a 3' position of ...
2
votes
1answer
64 views

Which Enzymes are Responsible for the Biodegradation of Noladin Ether?

Which enzymes degrade the CB1-specific endogenous cannabinoid 2-arachidonyl glyceryl ether? (Noladin ether)
2
votes
1answer
62 views

Which Enzymes are Responsible for the Biodegradation of Beta-endorphin?

Which enzymes are responsible for the biodegradation of the endogenous opioid peptide, beta-endorphin?
2
votes
0answers
43 views

Proteases in the blood

I’m reading on hormones and the book talks about how peptide or amine hormones are easily broken down by proteases present in the blood plasma. This has led me to question the interactions between ...
2
votes
0answers
19 views

What's the purpose of Cdk activity having more than one method of becoming inactive?

Cdk becomes partially active once its bound to cyclin and then gets phosphorylated and fully active once a Cdk-activating kinase (CAK) phosphorylates the partially active Cdk. This fully activated Cdk ...
1
vote
1answer
456 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, ...
1
vote
1answer
50 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?
1
vote
1answer
78 views

What is a detailed chemical explanation for describing how an enzyme may lower the activation energy of a reaction?

If you can provide some sound reasoning that touches on tertiary structures of proteins and does not use a lot of advanced chemistry jargon that might be really helpful, especially for an intro ...
1
vote
1answer
30 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 ...
1
vote
1answer
192 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 ...
1
vote
1answer
23 views

2 types of telomerases?

As telomerase works by adding new nucleotides complementary to the RNA it contains, it cannot work for the complementary strand. Say telomerase X has RNA complementary to the 5' to 3' strand it ...
1
vote
1answer
176 views

Creative ways to deactivate alpha-amylase taken from fungi

I can deactivate $\alpha$-amylase in ways such as extreme temperature controls, pH controls of the solution it stays in, or adding salt to the solution. However, are there any other unique or ...
1
vote
1answer
23 views

Difference between negative allosteric regulation and non-competitive inhibition

Both connect to some site other than the active site which controls the shape of the active site and causes the enzyme to be less active. So what is the difference?
1
vote
1answer
38 views

Why is binding energy the difference between ∆G catalyzed and ∆G uncatalyzed?

I think the title explains it pretty well -- I'm confused on what 1) exactly binding energy is 2) and why it's the difference. Like in this diagram: my teacher sort of said it was the energy the ...
1
vote
1answer
49 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?
1
vote
1answer
36 views

Correlating Ki values of pesticides to bacterial growth

Four pesticides P1 to P4 are reversible inhibitors of an enzyme E that is essential for the growth of a bacterium B. Their Ki values are given in the table below. Each of these four pesticides ...
1
vote
1answer
68 views

Carotenoid biosynthesis in yeast

Does Budding Yeast Sacchromyces cerevisiae produces significant amount of carotenoids? Have anybody estimated the ratio of flux going in branches 1. Cholesterol synthesis(via squalene) 2. Coenzyme Q6 ...
1
vote
0answers
22 views

Is it possible to separate the binding and catalysis of an enzyme in two steps?

Is it possible to do the following: Enzyme E binds to its substrate S without catalysis; Add a controllable stimulus, such as light, adding or removing chemicals; The enzymatic reaction is triggered ...
1
vote
1answer
45 views

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 ...
1
vote
0answers
34 views

How to calculate the LOB, LOD and LOQ of an enzyme assay

I understand how to calculate limit of blank (LOB), limit of detection (LOD), and limit of quantitation (LOQ) in the traditional way i.e., average and SD of raw analytical signal of blanks and low ...
1
vote
0answers
28 views

Invertase calculation?

If I wanted to make $500\mathrm{\mu g}/\mathrm{ml}$ of invertase, from Sigma's Invertase from Baker's yeast, which states is grade VII, and greater than or equal to $300 \mathrm{units}/\mathrm{ml}$, ...
1
vote
1answer
94 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 ...