Answer:
The correct answer is "Phosphoryl group transfer reactions; electron transfer reactions; concentration gradients across biological membranes".
Explanation:
The missing options of this question are:
1. Phosphoryl group transfer reactions
2. Electron transfer reactions
3. Concentration gradients across biological membranes
4. Protein synthesis
a. 2, 3, and 4
b. 1 and 2
c. 4
d. 1, 2, and 3
The correct answer is option d. "1, 2, and 3".
Free energy in cells is defined as forces that can be extracted from systems that allow cells to perform its biological activities. Phosphoryl group transfer reactions, electron transfer reactions and concentration gradients across biological membranes are three examples of sources of free energy in cells. Phosphoryl group transfer reactions regulate metabolism, gene regulation and signal transduction; electron transfer reactions participate in varios biological process at a molecular level; while concentration gradients across biological membranes are sources of stored energy and participate in vital processes such as cellular respiration.
