CHEMISTRY GLOSSARY

glucose    →   glukoza

Glucose (grape sugar, blood sugar), C₆H₁₂O₆, is an aldohexose (a monosaccharide sugar having six carbon atoms and an aldehyde group). An older common name for glucose is dextrose, after its dextrorotatory property of rotating plane polarized light to the right. Glucose in free (in sweet fruits and honey) or combined form (sucrose, starch, cellulose, glycogen) is is probably the most abundant organic compound in nature. During the photosynthesis process, plants use energy from the sun, water from the soil and carbon dioxide gas from the air to make glucose. In cellular respiration, glucose is ultimately broken down to yield carbon dioxide and water, and the energy from this process is stored as ATP molecules (36 molecules of ATP across all processes).

Naturally occurring glucose is D isomers (OH group on the stereogenic carbon farthest from the aldehyde group, C-5, is to the right in the Fischer projection). Although often displayed as an open chain structure, glucose and most common sugars exist as ring structures. In the α form, the hydroxyl group attached to C-1 and the CH₂OH attached to C-5 are located on opposite sides of the ring. β-glucose has these two groups on the same side of the ring. The full names for these two anomers of glucose are α-D-glucopyranose and β-D-glucopyranose.

radical    →   radikal

Radical is a reaction intermediate where a bond is broken and the two parts of the molecule exist carrying a single unshared electron. The radicals are normally destroyed quickly by recombination or they break into another radical and a stable molecule.

recrystallisation    →   rekristalizacija

Recrystallisation is a formation of a new, strain free grain structure from the existing one in cold worked metal, usually accomplished by heating. The change from one crystal structure to another, as occurs on heating or cooling through a critical temperature.

selenide    →   selenid

Selenides are compounds having the structure R-Se-R (R not equal to H). They are thus selenium analogues of ethers. Also used for metal salts of H₂Se.

solution    →   otopina

Solutions are homogeneous mixtures of clean substances. Solutions contain two or more substances mixed in a state of molecular dispersion. Component which is found in solution in greater amount than other components is called a solvent and other components are called dissolved substances. Solution can be unsaturated, saturated and oversaturated.

glutamic acid    →   glutaminska kiselina

Glutamic acid is an electrically charged amino acids. It is one of the two amino acids that contain a carboxylic acid group in its side chains. These acids play important roles as general acids in enzyme active centers, as well as in maintaining the solubility and ionic character of proteins. Glutamic acid is commonly referred to as glutamate, because its carboxylic acid side chain will be deprotonated and thus negatively charged in its anionic form at physiological pH. Glutamic acid is referred to as a non-essential amino acid because a healthy human can synthesize all the glutamic acid needed for normal body function from other amino acids.

• Abbreviations: Glu, E
• IUPAC name: 2-aminopentanedioic acid
• Molecular formula: C₅H₉NO₄
• Molecular weight: 147.13 g/mol

glutamine    →   glutamin

Glutamine is neutral amino acids with polar side chains. It serves as an important carrier of ammonia and contributes it to the formation of urea and purines. Glutamine is not recognized as an essential amino acid but may become conditionally essential in certain situations, including intensive athletic training or certain gastrointestinal disorders. It is synthesized by the enzyme glutamine synthetase from glutamate and ammonia.

• Abbreviations: Gln, Q
• IUPAC name: 2,5-diamino-5-oxopentanoic acid
• Molecular formula: C₅H₁₀N₂O₃
• Molecular weight: 146.14 g/mol

glycine    →   glicin

Glycine is the smallest amino acid and is unique because it lacks a side chain. This gives it more conformational freedom than any other amino acid. Glycine is often found in turns and loops where other amino acids would be sterically unacceptable. Although it is formally nonpolar, it’s very small side chain makes no real contribution to hydrophobic interactions. Glycine is not essential to the human diet, as it is biosynthesized in the body from the amino acid serine.

• Abbreviations: Gly, G
• IUPAC name: 2-aminoacetic acid
• Molecular formula: C₂H₅NO₂
• Molecular weight: 75.07 g/mol

solvation    →   solvatacija

Solvation is the process by which solvent molecules surround and interact with solute ions or molecules.

stereospecific reaction    →   stereospecifična reakcija

Stereospecific reactions are reactions that proceed predominantly to a single stereoisomeric product out. All metabolic conversions involving chiral molecules are stereospecific.