AST

AST is an acronym that can refer to several terms across different fields, including computer science, timekeeping, and biochemistry.

In computer science, AST stands for Abstract Syntax Tree, a tree-structured representation of the abstract syntactic structure of source code. An AST captures the essential elements of a program’s syntax while omitting unnecessary details of the concrete syntax. Parsers generate ASTs from source code, and compilers or interpreters traverse them for semantic analysis, type checking, optimization, and code generation. An AST is typically more compact than a parse tree and serves as the basis for program analysis and transformation.

In timekeeping, AST refers to Atlantic Standard Time, a time zone operating at UTC-4. It is used in parts of the Caribbean and in some eastern regions during standard time. Many places observe daylight saving time, switching to Atlantic Daylight Time (ADT), which is UTC-3. Some jurisdictions near the Atlantic coast do not observe DST and remain on AST year-round.

In biochemistry, AST stands for aspartate aminotransferase, an enzyme also known as AST or GOT. It catalyzes the transfer of an amino group from aspartate to alpha-ketoglutarate, producing oxaloacetate and glutamate. AST is present in several tissues, with high activity in the liver, heart, and muscles. Blood levels of AST are used in liver function testing; elevations can indicate hepatocellular injury but are not specific and are interpreted alongside other markers such as ALT and the clinical context.