Biomolecules: Functional Groups, Monomers/Polymers, and Carbohydrate Chemistry

Vocabulary flashcards covering functional groups, monomers/polymers, dehydration/hydrolysis, enzymes, and carbohydrate chemistry from the lecture notes.

Hydroxyl group (OH)

A functional group consisting of an oxygen atom bonded to a hydrogen. When attached to the main molecule, it influences reactivity and enables hydrogen bonding in aqueous environments.

Carbonyl group

A carbon atom double-bonded to oxygen (C=O). Two main forms in sugars: aldehyde and ketone.

Aldehyde

A carbonyl group at the end of a carbon chain, with at least one hydrogen attached to the carbonyl carbon.

Ketone

A carbonyl group located in the middle of the carbon skeleton, with carbon atoms on both sides.

Carboxyl group

A carbonyl carbon double-bonded to oxygen and single-bonded to a hydroxyl (–COOH). Usually at the end of a molecule and acidic.

Amino group

A nitrogen atom bonded to two hydrogens and the rest of the molecule (–NH2); can form up to three bonds and acts as a functional endpoint in amino acids.

Amino acid

The building block of proteins. A central (alpha) carbon bears an amino group, a carboxyl group, a hydrogen, and a variable side chain (R).

Thiol group

A sulfur atom bonded to a hydrogen (–SH). Influences polarity and can participate in hydrogen bonding and interactions with other groups.

Phosphate group

A phosphorus atom bonded to four oxygens (–PO4). Negatively charged, part of nucleic acid backbones and ATP energy storage.

Methyl group

A carbon atom bonded to three hydrogens (–CH3). Nonpolar end group common in organic molecules.

Monomer

A single building block that covalently bonds to form a polymer.

Polymer

A large molecule built from many monomers linked by covalent bonds.

Dehydration synthesis (dehydration reaction)

A reaction where water is removed as monomers join to form a covalent bond, producing a polymer.

Hydrolysis

A reaction where water is added to break covalent bonds between monomers, releasing smaller units.

Enzyme

A protein that acts as a biological catalyst to accelerate chemical reactions, including dehydration synthesis and hydrolysis.

Carbohydrate

A biomolecule class made of monosaccharides, disaccharides, and polysaccharides; major energy source for organisms.

Monosaccharide

A simple sugar with the general formula CH2O(n); includes aldose and ketose forms; examples: glucose, fructose, ribose, deoxyribose.

Glucose

A six-carbon aldose monosaccharide (C6H12O6) and a primary energy source; commonly exists in ring form in solution.

Fructose

A six-carbon ketose monosaccharide; an isomer of glucose.

Ribose

A five-carbon sugar found in RNA; part of the backbone of RNA.

Deoxyribose

A five-carbon sugar found in DNA that lacks one oxygen compared to ribose.

Disaccharide

Two monosaccharides linked by a covalent bond (glycosidic linkage); examples include sucrose, maltose, and lactose.

Glycosidic linkage

A covalent bond formed between two monosaccharides during dehydration synthesis.

Sucrose

Disaccharide composed of glucose and fructose.

Maltose

Disaccharide composed of two glucose units.

Lactose

Disaccharide composed of glucose and galactose.

Lactose intolerance

Condition caused by lack of lactase enzyme; inability to digest lactose in adulthood; variability across populations.

Oligosaccharide

A carbohydrate with a small number of monosaccharide units (3–10); can determine blood type via surface antigens.

Blood type antigens

Oligosaccharides on the surface of red blood cells that determine blood type (A, B, AB, or O).

Polysaccharide

A polymer of many monosaccharides; roles include energy storage (starch, glycogen) and structural support (cellulose).

Alpha glycosidic linkage

Glycosidic bond in which glucose monomers are linked in the alpha configuration, common in starch and glycogen.

Starch

Storage polysaccharide in plants; composed of glucose units linked by alpha glycosidic bonds.

Glycogen

Storage polysaccharide in animals; highly branched, composed of glucose units linked primarily by alpha glycosidic bonds.

Cellulose

Structural polysaccharide in plants; glucose units linked by beta-1,4 glycosidic bonds; not easily digested by humans.

Lipids

Hydrophobic biomolecules; not polymers with repeating subunits; include fats, oils, and cholesterol; roles include energy storage and membrane structure.

Proteins

Macromolecules composed of amino acids folded into specific 3D structures; perform most biological functions and build body structures.

Nucleic acids

Macromolecules (DNA and RNA) with a sugar–phosphate backbone and nucleotide subunits; store and transmit genetic information.

Nucleotides

Monomer units of nucleic acids; consist of a sugar (ribose or deoxyribose), a phosphate group, and a nitrogenous base.

ATP (adenosine triphosphate)

Energy currency of the cell; composed of adenosine and three phosphate groups; energy is released by hydrolysis of the terminal phosphate.

Adenosine

Part of ATP; adenine base attached to ribose sugar.

Ring form vs linear form (monosaccharides)

Monosaccharides can be linear; in aqueous solution they commonly form ring structures, which are the biologically relevant form in living organisms.