Final answer:
The molecular shape of a biological molecule is crucial because it influences how these molecules interact with each other, which in turn determines their biological function. The theory behind molecular shapes, known as VSEPR, describes how electron pair repulsion establishes the spatial configuration of atoms, affecting the molecule's interactions and activities in biological systems.
Step-by-step explanation:
The molecular shape of a biological molecule is important because it determines how biological molecules recognize and respond to one another. This is crucial as the specific shapes and chemical properties of molecules dictate their function. For example, the isomerism in organic molecules broadens the diversity of molecular shapes and therefore, the range of possible chemical reactions and interactions.
Valence shell electron pair repulsion (VSEPR) theory explains that molecular shape is influenced by the repulsion between negatively charged electron pairs, which determines the spatial arrangement of atoms. This molecular geometry is essential for biological molecules to fit together or interact correctly, just like a key fits into a lock, often referred to as the "lock and key" model for enzyme-substrate interactions.
Therefore, alterations in molecular shape can affect biological processes and functions, influencing everything from enzyme activity to DNA replication. The phrase 'form follows function' in biology exemplifies the importance of molecular shapes in determining the biological roles of molecules within cells and organisms.