Glucose Molecule Diagram Quiz – Find Each Carbon and Group

All 13 parts on the diagram

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The ring 8

Carbon 1 (anomeric carbon) It sits beside the ring oxygen, at the right corner. In the chain it is the carbon of the aldehyde group.
Carbon 2 The next carbon after carbon 1. Its hydroxyl group points down here and sits on the right of the chain.
Carbon 3 Its hydroxyl group points up, into the ring drawing. On the chain that group is written on the left.
Carbon 4 The left corner, opposite carbon 1. Its hydroxyl group points down.
Carbon 5 The last carbon in the ring. It is bonded to the ring oxygen and carries carbon 6.
Carbon 6 The only carbon outside the ring, above carbon 5. With its two hydrogen atoms and a hydroxyl group it is the CH₂OH group.
Ring oxygen The one oxygen atom in the ring. It joins carbon 1 to carbon 5 and comes from the hydroxyl group of carbon 5.
Hydroxyl group (OH) An oxygen atom bonded to a hydrogen atom. Glucose has five: one each on carbons 1, 2, 3, 4 and 6.

Chain, alpha and beta 5

Aldehyde group Carbon 1 with a hydrogen atom and a double-bonded oxygen. It is why glucose is called an aldose.
Hydroxyl on carbon 5 It bonds to carbon 1 to close the ring. Its oxygen becomes the ring oxygen. In D-glucose it is written on the right.
CH₂OH group Carbon 6 with two hydrogen atoms and a hydroxyl group. It stays outside the ring when the chain closes.
Alpha-glucose Its carbon 1 hydroxyl group points down. That is the opposite side from the CH₂OH group. About 36 percent of glucose in water is this form.
Beta-glucose Its carbon 1 hydroxyl group points up. That is the same side as the CH₂OH group. About 64 percent of glucose in water is this form.

How this list was compiled: Every name and every direction checked on 2026-10-03 against the PubChem records of D-glucose, alpha-D-glucose, beta-D-glucose and the open-chain form (https://pubchem.ncbi.nlm.nih.gov/compound/ followed by 5793, 79025, 64689 and 107526); Wikipedia: Glucose and Monosaccharide, text only; the IUPAC Nomenclature of Carbohydrates (rules 2-Carb-2 and 2-Carb-6, on the Queen Mary University of London site); a general chemistry textbook chapter on LibreTexts (Cyclic Structures of Monosaccharides); the UCLA Illustrated Glossary of Organic Chemistry; the Purdue University general chemistry pages on carbohydrates; and Kimball's Biology Pages: Carbohydrates. Licence: own work

The drawing: Drawn for this site on 2026-10-03 from plain geometry and the table derived from PubChem record 79025; nothing traced. Licence: own work

How it works

On this glucose molecule diagram quiz a carbon atom or a group is named and you tap it on the drawing. The ring comes first: eight questions. Five more follow on the chain and the alpha and beta rings.

Read the full guide

Carbon 1 or carbon 5, aldehyde or CH₂OH

Carbon 1 and carbon 5 both sit next to the ring oxygen. Carbon 5 is the one that holds another carbon above the ring, and that carbon is carbon 6. On the chain the two dashed boxes are the two ends: the aldehyde box holds an O on a double bond, the CH₂OH box two H and an OH.

Two ways of drawing one molecule

The ring is a Haworth projection: the ring drawn flat and seen from the side, with each group above or below it. The chain is a Fischer projection, read from carbon 1 at the top to carbon 6 at the bottom.

Any OH tablet on the ring is right for the hydroxyl group.
Alpha-glucose and beta-glucose are whole rings: tap anywhere on the one that is named.

Questions and answers

What is the anomeric carbon of glucose?

Carbon 1. In the chain it is the carbon of the aldehyde group. When the ring closes it gains a hydroxyl group that can point two ways, down or up, and the two rings that result, alpha and beta, are called anomers.

Is glucose an aldose or a ketose?

An aldose, because its open chain begins with an aldehyde group. A ketose has a ketone group inside the chain instead. With six carbon atoms, glucose is more exactly an aldohexose.

How many hydroxyl groups does glucose have?

Five. In the chain they are on carbons 2 to 6. In the ring they are on carbons 1, 2, 3, 4 and 6: the oxygen of carbon 5 has become the ring oxygen, and carbon 1 has gained a hydroxyl group.

What is the ring form of glucose called?

A pyranose: a six-membered ring of five carbon atoms and one oxygen atom. In water more than 99 percent of glucose is in this form. If the hydroxyl group on carbon 4 closes the ring instead, it is a much rarer five-membered ring, a furanose.