Final answer:
Anabolic pathways require a net input of energy to synthesize complex molecules from simpler ones and are integral for the cell's life, in contrast to catabolic pathways that generate energy by breaking down molecules.
Step-by-step explanation:
Anabolic pathways are those that require a net input of energy to synthesize complex molecules from simpler ones. This process includes the synthesis of sugars from carbon dioxide, large proteins from amino acids, and new strands of DNA from nucleic acid building blocks.
These pathways are vital for the cell's survival, operate continuously, and rely on the energy furnished by high-energy molecules like ATP, NADH, and NADPH.
In contrast, catabolic pathways release energy by breaking down larger molecules into smaller ones. This is exemplified by the digestion process where carbohydrates, fats, and proteins are broken down into their monomer units like simple sugars, fatty acids, glycerol, and amino acids, respectively. Both anabolic and catabolic pathways are essential for maintaining the cell's energy homeostasis.
Therefore, the correct aspect of anabolic pathways as per the student's question is c. reactions that require a net input of energy and reactions that result in the synthesis of large biomolecules.