Nucleic Acids Overview

Nucleoside analogs, when incorporated into viral DNA, lack a hydroxyl group, preventing the formation of sugar-phosphate bonds, halting viral replication.

HIV-1 (Human Immunodeficiency Virus type 1) is the virus that causes Acquired Immunodeficiency Syndrome (AIDS).

AIDS treatment often combines reverse transcriptase inhibitors with protease inhibitors, like saquinavir, to stop viral replication by preventing the synthesis of proteins needed for virus reproduction.

Drugs that block the enzyme reverse transcriptase, hindering the conversion of viral RNA to DNA, consequently preventing the virus from replicating itself.

Drugs that block viral proteases, preventing the formation of proteins used by viruses to create copies of themselves, thus thwarting replication.

Carbohydrates are molecules composed of carbon, hydrogen, and oxygen, often with the formula Cn(H₂O)n.

Nucleic acid sequences are read from the 5' end (phosphate group) to the 3' end (hydroxyl group).

Deoxyribose is the pentose sugar found in DNA.

Ribose is the pentose sugar in RNA.

Adenine (A) pairs with Thymine (T), and Guanine (G) pairs with Cytosine (C).

Viruses replicate only inside a host cell, taking over host cell resources for protein synthesis and growth.

Viruses contain either DNA or RNA (but not both) enclosed in a protein coat.

DNA is a double helix, composed of two polynucleotide strands intertwined.

In DNA, the number of purines (A and G) equals the number of pyrimidines (T and C).

The sequence that pairs with a DNA strand by base pairing follows A-T, G-C.

A 2D representation of a molecule, showing the spatial arrangement of atoms in a molecule; used to illustrate the configuration of stereoisomers, particularly in carbohydrates.

A monosaccharide with 5 carbon atoms and an aldehyde functional group.

A monosaccharide with 6 carbon atoms and an aldehyde functional group.

A monosaccharide with 5 carbon atoms and a ketone functional group.

A monosaccharide with 6 carbon atoms and a ketone functional group.

A stereoisomer in which the hydroxyl group on the chiral carbon furthest from the carbonyl group is on the right side of the Fischer projection.

A stereoisomer in which the hydroxyl group on the chiral carbon furthest from the carbonyl group is on the left side of the Fischer projection.

A cyclic representation of a monosaccharide; often used to show the ring form of a sugar in solution.

An aldopentose; a type of sugar.

A common aldohexose, also known as dextrose and blood sugar.

An aldohexose found in lactose.

Representations of cyclic forms of monosaccharides, typically pentoses and hexoses, showing ring structures and the arrangement of hydroxyl groups.

The most stable forms of pentoses and hexoses, forming rings due to the reaction of a specific –OH group with a carbonyl group.

A ketohexose monosaccharide, known for being sweeter than sucrose (table sugar).

A monosaccharide containing six carbon atoms and a ketone functional group.

Different stereoisomers of monosaccharides. They differ in the orientation of the hydroxyl group at a specific carbon atom and play role in reactions.

A specific way to draw the cyclic structure of a sugar, where carbons are at the ring corners, representing the arrangement of atoms in three-dimensional space.

A specific isomer of glucose, differing in the orientation of the hydroxyl group at carbon 1.

Another isomer of glucose, differing in the orientation of the hydroxyl group at carbon 1 from that of α-D-glucose.

The process where a cyclic sugar isomerizes to different isomers in an aqueous solution via an open chain intermediate.

A monosaccharide differing from glucose in the arrangement of its hydroxyl groups at certain carbons.

A way to represent the cyclic structure of monosaccharides, useful for showing structural arrangements in 2D.

A carbohydrate capable of reducing another substance, often due to its aldehyde or ketone group that can be oxidized easily.

A chemical solution used to detect the presence of reducing sugars through a color change when the Cu2+ ions are reduced to Cu+.

A simple sugar with 6 carbon atoms and an aldehyde functional group.

A simple sugar with 6 carbon atoms and a ketone functional group.

A sugar alcohol produced by the reduction of glucose.

Starch is composed of two polysaccharides: amylose and amylopectin.

Amylose is a continuous chain of α-D-glucose molecules linked by α-1,4-glycosidic bonds.

Amylopectin is a branched polysaccharide of α-D-glucose molecules linked by α-1,4-glycosidic bonds, with branches linked by α-1,6-glycosidic bonds.

Glycogen is a branched polysaccharide of α-D-glucose units, with branches every 10-15 glucose units, linked by α-1,6-glycosidic bonds.

Cellulose is an unbranched polysaccharide of β-D-glucose units linked by β-1,4-glycosidic bonds.

Glycosidic bonds are the bonds that link monosaccharides together to form polysaccharides.

Amylose accounts for about 20% of the starch structure and consists of 250–4000 α-D-glucose molecules connected in a continuous chain.

Amylopectin is the other main component of starch, and it is a branched polysaccharide that stores glucose.

Glycogen is a branched polysaccharide that stores glucose in animal cells. It is the main form of glucose energy storage for animals.

Cellulose is a structural polymer found in plants, a key component of wood and cotton.