Biomolecules - Carbohydrates and Chemistry of Cells

Vocabulary flashcards covering the chemical foundations of cells, atomic structures, functional groups, and carbohydrate classification from the lecture.

Atom

The smallest functional unit of matter that forms all chemical substances and cannot be further broken down into other substances by ordinary means.

Molecule

A structure composed of two or more atoms bonded together.

Compound

Any molecule composed of two or more different elements.

Proton

A subatomic particle with a positive charge ($+$) found in the nucleus of an atom.

Neutron

An uncharged neutral subatomic particle found in the nucleus of an atom.

Electron

A subatomic particle with a negative charge ($-$) found in atomic orbitals.

Organic Molecules

Carbon-containing molecules that are abundant in living organisms.

Functional Groups

Groups of atoms with special chemical features that are functionally important and exhibit the same properties in all molecules in which they occur.

Amino Group

A functional group ($-NH_2$) found in amino acids that is weakly basic, polar, and forms part of peptide bonds.

Carboxyl Group

An acidic functional group ($-COOH$) found in amino acids and fatty acids that gives up $H^+$ in water and forms part of peptide bonds.

Hydroxyl Group

A polar functional group ($-OH$) found in steroids, alcohol, carbohydrates, and some amino acids that forms hydrogen bonds with water.

Methyl Group

A nonpolar functional group ($-CH_3$) that may be attached to DNA, proteins, and carbohydrates.

Phosphate Group

A polar functional group ($-PO_4^{2-}$) found in nucleic acids, ATP, and phospholipids that is weakly acidic and negatively charged at typical pH of living organisms.

Sulfhydryl Group

A polar functional group ($-SH$) found in proteins containing the amino acid cysteine that forms disulfide bridges in many proteins.

Carbohydrates

The most abundant class of organic molecules in nature, composed of carbon, hydrogen, and oxygen with the general formula $C_n(H_2O)_n$.

Monosaccharides

Simplest single sugar units containing 3 to 7 carbon atoms in a ratio of $(CH_2O)$.

Isomers

Molecules that have the same chemical formula but different atomic arrangements, giving them distinct chemical and biochemical properties.

Glucose

A hexose sugar ($C_6H_{12}O_6$) produced by plants during photosynthesis that serves as the primary fuel for the brain.

Disaccharides

Carbohydrates composed of two monosaccharides joined together by a glycosidic bond.

Sucrose

Table sugar, a disaccharide formed by the dehydration synthesis of glucose and fructose ($C_{12}H_{22}O_{11}$).

Lactose

Milk sugar, a disaccharide composed of glucose and galactose.

Maltose

Malt sugar, a disaccharide formed by linking two glucose molecules.

Polysaccharides

Long polymer chains composed of many monosaccharides linked together.

Cellulose

A straight-chain glucose polymer (2,000–3,000 units) that forms structural fibers in plant cell walls.

Amylose

A linear, poorly water-soluble component of starch composed of glucose units linked by $\text{alpha } 1\text{-}4$ glycosidic bonds that forms a helical structure.

Amylopectin

A highly branched glucose polymer component of starch with linear $\text{alpha } 1\text{-}4$ linkages and $\text{alpha } 1\text{-}6$ branch points every 12–30 glucose residues.

Glycogen

A highly branched storage polysaccharide in animals found mainly in the liver and skeletal muscle, with branch points every 8–12 glucose units.

Chitin

A structural polysaccharide chemically related to cellulose, found in fungal hyphae cell walls and arthropod exoskeletons.

Glycosaminoglycans

Also called mucopolysaccharides, these carbohydrates are present in vertebrate connective tissue and function as lubricants in joints.