23 Answered Questions for the topic Enzymes

07/17/19

Do disaccharidases require a cofactor or coenzyme to function?

I'm doing research on lactose intolerance and am curious if disaccharidases (enzymes that break down disaccharides) require a cofactor or coenzyme to function? Reviews or references would be... more

07/15/19

How are lysosome membranes protected from the attack of hydrolases?

Lysosomes are a bit like the *suicidal bags* of cells. They help to clean cells, have an acidic pH and contain a large number of hydrolyzing enzymes. But why don't these hydrolyzing enzymes attack... more

07/12/19

Does alpha-amylase from different species have different *optimal* conditions?

Do the optimal conditions for the enzyme isoforms differ between species? Specifically, do the optimal pH and temperature for alpha-amylase differ for that enzyme produced by *B. lichiniformis* and... more

07/10/19

How are lysosome membranes protected from the attack of hydrolases?

Lysosomes are a bit like the *suicidal bags* of cells. They help to clean cells, have an acidic pH and contain a large number of hydrolyzing enzymes. But why don't these hydrolyzing enzymes attack... more

07/08/19

Why are enzyme-catalysed reactions slower at lower substrate concentration?

Suppose I'm using 200 nmoles of enzyme and 2 mmoles of substrate. The enzyme should be saturated but if I use 50 mmoles of substrate, the reaction will be faster. Why?I just can't get it! Even at... more

07/02/19

How can facultative anaerobes exist without catalase?

>Catalase-negative bacteria may be anaerobes, or they may be **facultative anaerobes** that only ferment and do not respire using oxygen as a terminal electron acceptor<br />A facultative... more

06/24/19

Why is it often the case that an enzyme is favorable only towards one direction of a reaction and not both directions?

In class when we're studying enzymes like amylase or protease it only works well when you're using it to break down compounds like polysaccharides. I'm just curious but why is it not possible for... more

06/24/19

Is there an enzyme for the transformation of the hydroxyl group?

I would like to know, is there any enzyme which does the transformation of hydroxyl group to any other functional group using the enzyme. The substrate is aromatic hydroxyl group. Product should... more

06/17/19

Do plants have cellulases?

I can't seem to find the answer to this. Not even Wikipedia could help- it mentioned bacteria and fungi that have cellulases but not plants. Using my own reasoning, I would think that - On the one... more

06/11/19

Why are plants unable to take up Phosphorus directly in their organic form like Phytic Acid?

I am researching acquisition strategies of phosphorus by decidious trees. I am reading a lot that plants take up nutrients as their inorganic form. In the case of P according to literature this is... more

06/01/19

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... more

05/24/19

How do bile salts affect lipase activity?

**BACKGROUND**: It is well known that bile salts are needed for emulsification of fats. It is then said that this increases the surface area for activity of pancreatic lipase, implying that bile... more

05/20/19

Can an adult without genetic lactase persistence still develop a tolerance for dairy foods?

While investigating the rise of adult lactose tolerance, I came across the news that China has been encouraging its citizens to drink more milk, even though most of the Asian population lacks the... more

05/10/19

Can an adult without genetic lactase persistence still develop a tolerance for dairy foods?

While investigating the rise of adult lactose tolerance, I came across the news that China has been encouraging its citizens to drink more milk, even though most of the Asian population lacks the... more

04/20/19

In which direction does ATP synthase rotate?

I heard about the rotation of ATP synthase in a biochemistry course. The professor said it will rotate counterclockwise. Is that true? If so, what mechanism defines its direction?

04/10/19

A codon is a group of three bases that specifies a particular amino acid. Which of the following enzymes can ‘read’ codons on an mRNA?

a.DNA polymeraseb.Ribosomec.Primased.RNA polymerase 

04/04/19

What effect has changing pH and salt concentration on protein complexes?

I'm struggling to find peer reviewed literature that explains the effect of changing the pH and the salt concentration on protein/protein complexes in solution. What effect does the pH and the salt... more

03/15/19

What is the biological mechanism underlying caffeine intolerance? (CYP1A2 or other?)?

As far as I can tell, caffeine metabolism occurs primarily via the CYP1A2 enzyme. I am curious as to whether mutations in the CYP1A2 gene are associated with caffeine intolerance. Some site that... more

03/15/19

Examples of enzymes working in reverse?

I have always been taught that enzymes can catalyze both the forward and reverse reaction, and will increase the reaction rate in both directions. I understand that the thermodynamics of the... more

03/15/19

Is the EC50 of an activating protein for an enzyme a good indicator for the binding affinity Kd?

We work with a membrane protein system where measuring the affinity between the enzyme and the upstream activating protein has been difficult, and when measured in detergent solution, it is almost... more

03/14/19

What is the biological mechanism underlying caffeine intolerance? (CYP1A2 or other?)?

As far as I can tell, caffeine metabolism occurs primarily via the CYP1A2 enzyme. I am curious as to whether mutations in the CYP1A2 gene are associated with caffeine intolerance. Some site that... more

11/01/18

Why are enzymes sometimes considered the "lock and key" model?

Why are enzymes sometimes considered the "lock and key" model? Please provide me an easy definition because I have to remember this for a test.

04/27/16

enzymes * the dna

Enzymes * the DNA. Fill in the blank.

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