BIOORGANIC CHEMISTRY Flashcards
(40 cards)
saponification
is the process of breaking down the lipid matrix in foods and biological tissues to release carotenoids, using potassium hydroxide as the saponifying agent.
Classification of lipids
lipids may be divided into eight categories: fatty acyls, glycerolipids, glycerophospholipids, sphingolipids, saccharolipids, and polyketides (derived from condensation of ketoacyl subunits); and sterol lipids and prenol lipids (derived from condensation of isoprene subunits).
The physiological role of fatty acids
FFAs are physiologically active, not only as nutritional components, but also as molecules involved in cell signaling and stabilization of membranes via palmitoylation and myristoylation. Protein palmitoylation is involved in numerous cellular processes, including apoptosis, and neuronal transmission.
Transamination
the most common reaction type catalyzed by PLP-dependent enzymes. It is a biologically important process by which living cells reversibly transfer the amino group from an amine (e.g., γ-aminobutyrate) or α-amino acid (e.g., aspartate) to an α-keto carboxylic acid (e.g., α-ketoglutarate).
The principle of chemical peptide synthesis
Peptides are chemically synthesized by the condensation reaction of the carboxyl group of one amino acid to the amino group of another.
Biological importance of peptides.
Peptides function as neurotransmitters, neuromodulators, and hormones in receptor-mediated signal transduction. They influence cell-cell communication upon interactions with receptors, and are involved in a number of biochemical processes, such as metabolism, pain, reproduction, and immune response
Naturally occurring peptides
The distinction is based largely on the fact that naturally occurring peptides are composed of amino acids with uncommon configurations and structures, and of linkages other than the classical peptide bond.
importance of glutathione
a substance made from the amino acids glycine, cysteine, and glutamic acid. It is produced by the liver and involved in many body processes. Glutathione is involved in tissue building and repair, making chemicals and proteins needed in the body, and in immune system function.
antimicrobial peptides
Antimicrobial peptides (AMPs) are a class of small peptides that widely exist in nature and they are an important part of the innate immune system of different organisms. AMPs have a wide range of inhibitory effects against bacteria, fungi, parasites and viruses.
important peptide hormones
insulin, glucagon, oxytocin, and vasopressin. Insulin: It is a peptide hormone secreted by the pancreas. It performs anabolic processes such as glycogen synthesis, fatty acids, protein, and inhibits catabolic processes like the breakdown of fats and glycogen.
Biological functions of proteins
Proteins serve as structural support, biochemical catalysts, hormones, enzymes, building blocks, and initiators of cellular death. Proteins can be further defined by their four structural levels: primary, secondary, tertiary, and quaternary.
three-dimensional structure of proteins
Primary structure is the amino acid sequence.
Secondary structure is local interactions between stretches of a polypeptide chain and includes α-helix and β-pleated sheet structures.
Tertiary structure is the overall the three-dimension folding driven largely by interactions between R groups.
Quaternary structure exists in proteins consisting of two or more identical or different polypeptide chains (subunits). These proteins are called oligomers because they have two or more subunits. The quaternary structure describes the manner in which subunits are arranged in the native protein.
Purification of proteins
Protein purification is a fundamental process in biochemistry and biotechnology, aiming to isolate specific proteins from complex mixtures. It involves techniques like chromatography, centrifugation, and electrophoresis, supported by reagents and consumables.
Classification of carbohydrates and monosaccharides
Carbohydrates are divided into four types: monosaccharides, disaccharides, oligosaccharides, and polysaccharides. Monosaccharides consist of a simple sugar; that is, they have the chemical formula C6H12O6. Disaccharides are two simple sugars.
hemiacetal formation
when an aldehyde reacts with an alcohol. This can occur with neutral reaction, which only involves the alcohol and the aldehyde, or an acid catalyzed reaction, which puts a hydrogen on the aldehyde oxygen to start out with and is much faster.
Haworth formulas
Haworth projection is a common way of writing a structural formula to represent the cyclic structure of monosaccharides with a simple three-dimensional perspective.
Mutarotation
is a change in the optical rotation of a solution due to a change in the equilibrium between alpha (ɑ) and beta (β) anomers, upon dissolution in the aqueous solution. The process is also known as anomerization.
Chemical properties of monosaccharides
They undergo oxidation to from carboxylic acids.
They can be reduced to form polyalcohol or polyol.
They react with acids to form esters.
They can be fermented in the absence of oxygen to yield alcohol and carbon dioxide.
blood-type antigens.
Blood group antigens are either sugars or proteins, and they are attached to various components in the red blood cell membrane. For example, the antigens of the ABO blood group are sugars. They are produced by a series of reactions in which enzymes catalyze the transfer of sugar units.
Classification of steroids
they are mainly grouped into two classes- corticosteroids (includes glucocorticoids and mineralocorticoids), and sex steroids (includes progesterone, androgens and estrogens).
steroids biological functions
Steroids have two principal biological functions: as important components of cell membranes that alter membrane fluidity; and as signaling molecules. Examples include the lipid cholesterol, sex hormones estradiol and testosterone, anabolic steroids, and the anti-inflammatory corticosteroid drug dexamethasone.
chemical properties of cholesterol
Cholesterol is a 27 carbon compound with a unique structure with a hydrocarbon tail, a central sterol nucleus made of four hydrocarbon rings, and a hydroxyl group. The center sterol nucleus or ring is a feature of all steroid hormones.
Bile acids detergent effect
Bile acids are synthesized from cholesterol and are known to be involved with the emulsification and digestion of dietary lipids and fat-soluble vitamins. Outside of this role, bile acids can act as cell signaling effectors through binding and activating receptors on both the cell membrane and nucleus.
Bile acids amphipathic nature
Bile acids are a family of amphipathic (they have a hydrophilic (“water-loving”) or polar end and a hydrophobic (“water-fearing”) or nonpolar end) molecules generated from cholesterol in the liver which facilitate the digestion of lipids. Primary bile acids, cholic acid (CA) and chenodeoxycholic acid (CDCA), are conjugated to either glycine or taurine before excretion into the intestinal lumen.
