BIOORGANIC CHEMISTRY

Question 1

saponification

Answer 1

is the process of breaking down the lipid matrix in foods and biological tissues to release carotenoids, using potassium hydroxide as the saponifying agent.

Question 2

Classification of lipids

Answer 2

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).

Question 3

The physiological role of fatty acids

Answer 3

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.

Question 4

Transamination

Answer 4

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).

Question 5

The principle of chemical peptide synthesis

Answer 5

Peptides are chemically synthesized by the condensation reaction of the carboxyl group of one amino acid to the amino group of another.

Question 6

Biological importance of peptides.

Answer 6

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

Question 7

Naturally occurring peptides

Answer 7

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.

Question 8

importance of glutathione

Answer 8

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.

Question 9

antimicrobial peptides

Answer 9

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.

Question 10

important peptide hormones

Answer 10

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.

Question 11

Biological functions of proteins

Answer 11

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.

Question 12

three-dimensional structure of proteins

Answer 12

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.

Question 13

Purification of proteins

Answer 13

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.

Question 14

Classification of carbohydrates and monosaccharides

Answer 14

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.

Question 15

hemiacetal formation

Answer 15

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.

Question 16

Haworth formulas

Answer 16

Haworth projection is a common way of writing a structural formula to represent the cyclic structure of monosaccharides with a simple three-dimensional perspective.

Question 17

Mutarotation

Answer 17

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.

Question 18

Chemical properties of monosaccharides

Answer 18

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.

Question 19

blood-type antigens.

Answer 19

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.

Question 20

Classification of steroids

Answer 20

they are mainly grouped into two classes- corticosteroids (includes glucocorticoids and mineralocorticoids), and sex steroids (includes progesterone, androgens and estrogens).

Question 21

steroids biological functions

Answer 21

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.

Question 22

chemical properties of cholesterol

Answer 22

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.

Question 23

Bile acids detergent effect

Answer 23

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.

Question 24

Bile acids amphipathic nature

Answer 24

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.

Question 25

properties of nucleosides

Answer 25

Nucleosides consist of a purine or a pyrimidine base and a ribose or a deoxyribose sugar connected via a β-glycosidic linkage. These compounds are associated with structures of RNA (ribose sugars) and DNA (deoxyribose sugars).

Question 26

chemical properties nucleotides

Answer 26

Nucleotides are composed of phosphoric acid, a pentose sugar (ribose or deoxyribose), and a nitrogen-containing base (adenine, cytosine, guanine, thymine, or uracil). Ribonucleotides contain ribose, while deoxyribonucleotides contain deoxyribose

Question 27

biological role of nucleotides

Answer 27

Nucleotides have a central role in the physiology of organisms as building blocks of nucleic acids, storage of chemical energy, carriers of activated metabolites for biosynthesis, structural moieties of coenzymes, and metabolic regulators.

Question 28

Nucleotide coenzymes

Answer 28

There are four “great” nucleotide coenzyme couples [ATP]/[ADP] [Pi], [Acetyl CoA]/[CoASH], [NAD+]/[NADH] and [NADP+]/[NADPH]. Three components: The nucleotide coenzymes are modified ribonucleotides. All nucleotides are composed of three parts, a nitrogenous base, a pentose sugar, and a phosphate group.

Question 29

Classification of RNA

Answer 29

Three main types of RNA are involved in protein synthesis. They are messenger RNA (mRNA), transfer RNA (tRNA), and ribosomal RNA (rRNA). rRNA forms ribosomes, which are essential in protein synthesis. A ribosome contains a large and small ribosomal subunit

Question 30

classification of vitamins

Answer 30

Vitamins can be classified as water-soluble or fat-soluble. The fat-soluble vitamins include vitamins A, D, E, and K. Fat-soluble vitamins play integral roles in a multitude of physiological processes such as vision, bone health, immune function, and coagulation.

Question 31

Provitamins

Answer 31

A provitamin is a compound that can be converted in the body to a vitamin. These compounds are generally found as naturally occurring plant pigments which give the characteristic yellow, orange and red colours to a wide range of fruits and vegetables.

Question 32

hypervitaminosis

Answer 32

a condition of abnormally high storage levels of vitamins, which can lead to various symptoms as over excitement, irritability, or even toxicity.

Question 33

hypovitaminosis

Answer 33

Vitamin deficiency is caused by nutritional inadequacy, or may result from malabsorption, effects of pharmacological agents, and abnormalities of vitamin metabolism or utilization in the metabolic pathways.

Question 34

Vitamins as coenzymes

Answer 34

Vitamin K. The primary role of vitamin K is to serve as a coenzyme in the carboxylation of glutamic acid residues; this post-translational modification is required for the functioning of many proteins required for blood clotting.

Question 35

Definition of alkaloids.

Answer 35

a class of basic, naturally occurring organic compounds that contain at least one nitrogen atom. This group also includes some related compounds with neutral and even weakly acidic properties. Some synthetic compounds of similar structure may also be termed alkaloids.

Question 36

importance of alkaloids.

Answer 36

Alkaloids can alter DNA, selectively deform cells, and cause locoism. Some alkaloid molecules, both natural and synthetic, can act as narcotics. Moreover, they play a very important role in the immune systems of animals and plants.

Question 37

Classification of alkaloids

Answer 37

alkaloids are the tropanes, pyrrolidines, indoles, isoquinolines, and steroids and terpenoids. In other ways, alkaloids are classified based on the biological system where they take place.

Therapeutically, alkaloids are particularly well known as anaesthetics, cardioprotective, and anti-inflammatory agents. Well-known alkaloids used in clinical settings include morphine, strychnine, quinine, ephedrine, and nicotine

Question 38

Definition of antibiosis

Answer 38

an antagonistic association between two organisms (especially microorganisms), in which one is adversely affected. Bacteria produce heterogeneous organic compounds with low-molecular weights that act against pathogens in their growth and development.

Question 39

antibiotics

Answer 39

Antibiotics are chemical compounds used to kill or inhibit the growth of bacteria. Strictly speaking, antibiotics are a subgroup of organic anti-infective agents that are derived from bacteria or moulds that are toxic to other bacteria. ex Penicillins

Question 40

Role of heme in hemoglobin and
myoglobin

Answer 40

Myoglobin and hemoglobin both contain heme groups to bind oxygen, but differ in structure - myoglobin is spherical while hemoglobin is a tetramer. This allows hemoglobin to exhibit cooperative binding and transport oxygen more efficiently than myoglobin via conformational changes.