AP BIOLOGY

Detailed explanation-1: -The metabolism-first hypothesis means that ordered chemical reactions, and not replication was the property of the initial form that led to “life” and the interlocked networks of chemical reactions that evolved in complexity over time. Replicator-first scenarios require both replication and at least some heredity.

Detailed explanation-2: -In the first half of the 20th century, Alexander Oparin established the “Metabolism First” hypothesis to explain the origin of life, thus strengthening the primary role of cells as small drops of coacervates (evolutionary precursors of the first prokaryote cells).

Detailed explanation-3: -The GNC hypothesis or GNC-SNS primeval genetic code hypothesis refers to a hypothesis about the origin of genes. It suggests the universal genetic code originated not from a three-amino acid system, but from a four-amino acid system. It is this GNC code encoding [GADV]-proteins which is the most primitive genetic code.

Detailed explanation-4: -A fundamental task of proteins is to act as enzymes-catalysts that increase the rate of virtually all the chemical reactions within cells. Although RNAs are capable of catalyzing some reactions, most biological reactions are catalyzed by proteins.