Question

Choose the correct answers from the alternatives given:
An exergonic reaction
A. A spontaneous reaction in which energy is given off
B. An uphill reaction requiring input of energy
C. An anaerobic reaction
D. An oxidation reaction

Answer 1

Exergonic reactions, in terms of chemistry, are reactions where the change in free energy is negative. The total amount of energy available in a system is determined by free energy; negative changes mean that energy has been produced, whereas positive changes mean that energy has been retained.

Complete Answer:
- An exergonic reaction is a free energy releasing reaction. Since energy is released rather than absorbed by this form of reaction, it can occur naturally, without being forced by outside influences. Reactions where chemical bonds are broken are also exergonic reactions, releasing the energy in those bonds. The destructive aspect of metabolism, these reactions where chemicals are broken down, are called "catabolism."The chemical bonds in molecules like carbohydrates, proteins , and fats can be used as energy storage for living organisms.

- This can be seen in metabolism, where the absorption of energy from photosynthesis or cellular respiration produces sugars, proteins , and fats. When the organism requires energy, it can be seen again and these molecules are broken down.

- While there are spontaneous breakdowns of sugars, fats, and other exergonic reactions, living organisms use enzymes to significantly speed up these reactions.
- In order to start the reaction, the enzymes operate by taking the substrate molecule (such as a fat or sugar to be metabolised) into an ideal structure. This reduces the exergonic reaction's activation energy , making it much more likely to occur.
- Exergonic reactions in a single molecule, such as sugar or fat, and in an active form, such as ATP, are used by living organisms to transfer energy out of' storage.' This is achieved by breaking the chemical bonds in the fat or sugar and transferring the energy to a new molecule in the form of electrons or another currency.

The correct answer is option (A) A spontaneous reaction in which energy is given off.

Note: Using electron transport chains and other highly advanced chemical devices, the highly efficient cellular respiration process produces a startling 38 molecules of ATP from a single glucose molecule (although six ATP molecules are consumed in the process, for a net gain of 32).Only less efficient species can harness sufficient energy from the breaking of glucose bonds to create a few ATP molecules, but this is still enough to sustain life.