Question

Cell Physiology

Please note that all questions must be answered in your own, computer-typed, size-12 font words (English or Spanish, your choice) and be limited to 500 total words with single spacing. Anyone found presenting another’s work (regardless of source) as her/his own will receive a failing grade in the course. You must limit each answer to 500 words.

In your own words, respond to any four (your choice) of the following five essay questions: you must limit each answer to no more than 500 single words.

1. Describe enthalpy with respect to free energy change.

2. Describe the term endergonic with respect to a system’s free energy change.

3. Distinguish between free energy of a reaction and activation energy for that same reaction.

4. What is an enzyme mechanism?

5. Distinguish between competitive and non-competitive control of an enzyme.

Answer 1

Question 3:

Free energy of a reaction-

1. It the energy difference between the reactant and the product of a reaction.
2. It is also called the Gibbs free energy.
3. Denoted by delta G°

Activation energy

1. The energy difference between the ground state and the transition state of a reaction.
2. Highter the activation energy slower the rate of reaction
3. It is denoted by delta G# (hash in prefix).

Question 1: enthalpy is the heat energy of the system stored in a molecule or bond ,it is measured using the change in potential energy of the system. Also it is not dependent on the reaction pathway. It's of two type

1. Endothermic-heat energy taken by the system
2. Exothermic-heat energy is released by the system.

The formula is

H= E+pv where e is the internal energy ,p is pressure and v is the volume of the given reaction

Question 2: it the type of reaction where additional amount of heat is supplied to the reaction in order to make the free energy of the system positive. It is the energy difference between the product and the reactant of the system where the energy of the product is higher than the reactant. It is non spontaneous in nature that is it requires additional driving force or heat supply from the external and not given by the system on its own to occur naturally in the system . Here heat is absorbed by the system. It is very natural in system the examples are the Na+/k + pump in the body which cause several biological implementation of the pathways and muscle contraction and helps in nerval system

Question 5:

Competative control of energy-

1. The structure and the shape of the substrate and the inhibitor are almost similar.
2. Occupies the active site of the enzyme in order to lower the rate of reaction.
3. After binding it donot change the structure of the active site.
4. The increase in concentration of substrate reduce the inhibition rate of the reaction that is the rate of binding the inhibitor in active site reduces.
5. Example is succinate dehydrogenase is inhibited by malonate

Non competative :

1. The structure of the substrate and the inhibitor is different.
2. Here the inhibitor binds to the allosteric site of the enzyme
3. It changes the structure of active site of the enzyme after binding.
4. The substrate concentration alterations donot cause any changes in inhibition rate.
5. Example pyruvate kinase inhibited by alanine