Affinity—commonly described as the strength of binding between a peptide and its biological target—is a foundational concept in molecular biology, biochemistry, drug discovery, and biomedical engineering. For researchers, clinicians, and biotechnology developers, understanding affinity helps predict how effectively a peptide can recognize, bind, and influence a specific molecule within complex biological systems. This article provides a clear, search-optimized, and fully original explanation of affinity, how it is measured, and why it matters. What Is Affinity? Affinity refers to the quantitative strength of the interaction between a peptide and its target, such as a protein, receptor, enzyme, or other biomolecule. When a peptide binds strongly to its target, the system is said to have high affinity; when the binding is weak or transient, it exhibits low affinity. In molecular terms, affinity represents the balance between: Association (binding) Dissociation (unbinding) A high-affinity interaction favors stable attachment, often requiring only a small amount of peptide to achieve effective binding. Why Affinity Matters in Peptide Science 1. Precision in Drug Design Peptide-based therapeutics rely heavily on affinity to determine: How well a peptide recognizes a disease-related target Whether the binding is strong enough to produce a therapeutic effect…