Carbohydrates Chemistry Quiz

Carbohydrates are organic compounds that are made up of carbon, hydrogen, and oxygen. They are classified as polyhydroxy aldehydes or ketones or substances that yield such compounds on hydrolysis.

They provide energy through oxidation (breaking down carbohydrates to release energy), supply carbon for the synthesis of cell components, serve as a form of stored chemical energy, form part of the structures of some cells and tissues, and are components of cell membranes and receptors. Excess carbohydrates are converted to fat.

Monosaccharides are simple sugars that cannot be broken down into simpler units. They are the building blocks for more complex carbohydrates.

Disaccharides are formed when two monosaccharides are joined together by a glycosidic bond, with the loss of a water molecule. Examples include sucrose, lactose, and maltose.

Polysaccharides are complex carbohydrates that are made up of many monosaccharide units joined together by glycosidic bonds. They are classified as homopolysaccharides (only one type of sugar) or heteropolysaccharides (different types of sugar).

They contain 3 carbon atoms. For example, glyceraldehyde and dihydroxyacetone.

They contain 4 carbon atoms. They are less abundant than other monosaccharides but play a role in various metabolic pathways.

They contain 6 carbon atoms. Examples include glucose, fructose, galactose, and mannose.

A carbon atom bonded to four different groups. It's like a special carbon center that creates mirror-image versions of molecules.

Molecules with the same molecular formula but different spatial arrangements. They're like twins that look different in the mirror.

Mirror images of molecules that can't be superimposed on each other. Think of your left and right hands.

Isomers that differ at only one chiral carbon. Think of two friends who are mostly alike but have different hair colors.

A type of isomer that has a different configuration of the carbonyl group in a cyclic sugar. Think of a change in the sugar's ring structure.

Isomers with the same molecular formula but different functional groups. Think of a sugar with an aldehyde or ketone group.

Substances that rotate the plane of polarized light. Think of a light beam spinning as it passes through a molecule.

The simplest carbohydrate, a 3-carbon sugar with an aldehyde group. It's like the building block of carbohydrates.

A five-carbon sugar with three chiral carbons, resulting in eight possible stereoisomers.

A six-carbon sugar with four chiral carbons, resulting in sixteen possible stereoisomers.

Cyclic forms of sugars that contain a six-membered ring, resembling a pyran molecule.

The carbon in a cyclic sugar that was involved in forming the ring. It's carbon-1 for aldoses and carbon-2 for ketoses.

The process of interconversion between the alpha and beta anomers of a sugar through the open-chain form.

Sugars that have the same molecular formula but differ in the functional group at one specific carbon atom.

A crucial component of RNA and coenzymes such as ATP, NAD, and NADP.

D-Fructose is a monosaccharide found in fruit juices and honey. It's obtained from the hydrolysis of starch, cane sugar, maltose, and lactose. It's an isomer of glucose, with the anomeric carbon at C2.

D-Galactose is a constituent of galactolipids and glycoproteins. It is found in cell membranes and the extracellular matrix.

When glucose is treated with concentrated hydroiodic acid, it loses all its oxygen and converts to iodohexane. This proves that glucose has a linear structure, without any branching.

Monosaccharide -OH groups react with acids like phosphoric acid, sulfuric acid, acetic acid, benzoic acid, etc., to form esters. Phosphate esters like glucose-1-phosphate and glucose-6-phosphate are crucial in glucose metabolism. Sulfate esters like galactose-3-sulfate also have biological significance.

Monosaccharides are powerful reducing agents in alkaline conditions. The free aldehyde or keto group tautomerizes to form a reactive enediol group. This reaction is known as the Lobry de Bruyn-Van Ekenstein transformation.

In the presence of oxidizing agents like cupric ions, sugars break at the double bond of the enediol group, forming a mixture of carboxylic acids. This reaction is the basis for Benedict's test.

Benedict's reagent is a blue solution containing copper sulfate, sodium carbonate, and sodium citrate. It detects the presence of sugars with free aldehyde or ketone groups. In the reaction, cupric ions are reduced, forming a red copper(I) oxide precipitate. This is the basis for diagnosing diabetes mellitus by testing glucose in urine.

Tollen's test uses ammoniacal silver nitrate solution. Sugars reduce this solution to metallic silver, forming a silver mirror on the test tube walls.

A type of carbohydrate that is formed when long chains of sugars are linked to a protein molecule.

A special type of glycoprotein where the sugar content is very high (more than 10%).

The main building blocks of bacterial cell walls are repeating units of N-acetylmuramic acid (NAM) and N-acetylglucosamine (GluNac).

Penicillin works by inhibiting the synthesis of the complex polysaccharides found in bacterial cell walls, effectively preventing the bacteria from building their protective barriers and leading to their death.

Hyaluronic acid is a type of mucopolysaccharide found in connective tissues, tendons, synovial fluid, vitreous humor, and other bodily fluids. It acts as a lubricant in joints, providing smooth movement between bones.

Reducing agents like Na-amalgam or H2 convert sugars into corresponding alcohols. For example, glucose forms sorbitol, fructose forms both sorbitol and mannitol, and galactose forms dulcitol.

The hexaphosphoric ester of inositol. It forms insoluble salts with essential minerals like calcium, magnesium, iron, and copper. This hinders their absorption from the diet, potentially impacting nutrient availability.

Deoxysugars are modified sugars where an -OH group is replaced by a hydrogen atom. 2-deoxyribofuranose is a vital component of DNA, while L-fucose and 6-deoxy-L-galactose play crucial roles in cell membranes and blood group antigens.

Aminosugars are formed by replacing the -OH group at C2 of a monosaccharide with an amino (NH2) group. They are crucial components of GAGs and some glycolipids. They can be further modified by acetylation and sulfation.

Aminosugars linked to 3-carbon acids. They are important components of cell membranes and play vital roles in cell recognition and interaction.

Glycosides are formed when a sugar's anomeric carbon reacts with alcohols or phenols. The sugar involved determines the name, and the linkage is named after the sugar.

A type of glycosidic linkage where the sugar involved is fructose. This is common in disaccharides like sucrose.