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1

To better understand the activation energy concept my teacher had given us an excellent example. Suppose you are driving a car and want to cross a mountain. You could either go to the mountain summit and then come down or you could directly cross it through a tunnel. What enzyme does is to construct a tunnel for the reaction to proceed.


1

The activation energy for a reaction is given for a given extent of reaction, typically per mole of product formed. In general, the amount of enzyme present in the reactor is irrelevant with respect to the activation energy. So option a) is closest to correct. However, note that the activation energy does not tell you how much energy is consumed taken up ...


2

The reaction barrier (also termed activation energy) is the energy that is needed for the reaction to take place. An enzyme is "only" a catalysator which lowers the necessary energy (and/or makes the reaction possible under the conditions) but some energy to start a chemical reaction is still needed. See this image (from here): To your questions: A and B ...


1

The processes that occur at the ER membrane in eukaryotic cells take place directly at the bacterial plasma membrane. Phospholipids are synthesised and inserted at the plasma membrane, and there is a protein translocation apparatus for translocation of proteins into the periplasmic space and insertion of transmembrane proteins into the plasma membrane.


1

In the beta-Lactamase test, an inhibitor of beta-Lactamase is added to a sample of the culture medium. The inhibitor binds to the enzyme and changes its color, which is in direct correlation to the concentration of the beta-Lactamase. More b-lactamase means more inhibitor binding and this results in more color development leading to a higher absorption. So ...


3

Proteins are polymers of amino acids. Each amino acid has a side chain. Many of these side chains contain ionisable groups. The ionization state of these groups is dependent on the pH. A group that is protonated at pH=2 and neutral, for example, may become deprotonated at pH=8 and become negative. See the Henderson-Hasselbalch equation. Protein structure is ...


2

Enzyme function is largely determined by it's 3-D shape. Enzyme shape is affected by pH among a couple other things. The enzyme only retains its optimal shape at the optimal pH, as you creep outside of it the enzymes shape changes and hence so does its function.


4

Enzymes have a more or less narrow optimal pH at which they work, depending on the conditions of their environment. Pepsin for example is active in the stomach which is pretty acidic and has an optimal pH of 2.0, while Trypsin, which is active in the small intestine has an optimal pH around 8.5. Changes in the pH first affect the form of the protein, ...


1

This is speculation, as I haven't done or read of the required experiment. However, I imagine that this would not be a problem. You're right that the RNA template (TERC) would not hybridize with a poly-G sequence, and so the telomerase would not be able to add more telomere repeats. You can imagine that the poly-G sequence is a cap, preventing telomerase ...


2

I'll give you examples I have encountered in talks. There are too many variations and types of applications for me to break out in a comprehensive way. Example 1: enzyme production. this sort of application is about optimizing the amount of a desirable enzyme or protein produced from a liquid culture. Sorry if this is too close to cell growth, but its ...



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