In chemical formulas of functional groups, the symbol $$R$$ represents a 'residue,' which denotes the remainder of the molecule. This residue can be a single hydrogen atom or a complex group containing many atoms.

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Functional groups are specific groups of atoms within biomolecules that are characterized by their particular chemical composition and the chemical reactions they perform, regardless of the larger molecule containing them. These groups can range in complexity from one or two atoms to combinations of multiple simpler functional groups.

Functional groups

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Microbiology covers the scope and sequence requirements for a single-semester microbiology course for non-majors. The book presents the core concepts of microbiology with a focus on applications for careers in allied health. The pedagogical features of the text make the material interesting and accessible while maintaining the career-application focus and scientific rigor inherent in the subject matter. Microbiology’s art program enhances students’ understanding of concepts through clear and effective illustrations, diagrams, and photographs.

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Residue in Chemical Formulas

A carbonyl group is a functional group consisting of a carbon atom double-bonded to an oxygen atom ($$C=O$$). It is present in several classes of organic compounds, either as a standalone group or as a component of larger functional groups like ketones, aldehydes, carboxylic acids, and amides.

Carbonyl Group

Ketones are a class of organic compounds containing a carbonyl group ($$C=O$$) that is located at an internal position within the carbon chain of the molecule.

Ketones

Aldehydes are a class of organic compounds containing a carbonyl group ($$C=O$$) that is located at the terminal position (end) of the carbon chain.

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