Carbohydrates Flashcards
Define monosaccharide.
Single sugar unit with the general formula (CH2O)n.
What is the most common number of carbon atoms for a monosaccharide to have? What is the sugar referred to as if it has this number of carbon atoms?
6 - a hexose sugar
What do the monosaccharides glucose, galactose, and fructose have in common?
They all contain 6 carbon atoms, making them hexose sugars.
Define disaccharide.
Two single sugar units joined by a condensation reaction. Composed of two monosaccharides.
What kind of bond holds disaccharides together?
Glycosidic bond.
Which two monosaccharides form the disaccharide sucrose?
Glucose and fructose.
Which two monosaccharides form the disaccharide maltose?
Two glucose molecules.
Which two monosaccharides form the disaccharide lactose?
Galactose and glucose.
What kind of reaction creates a glycosidic bond between disaccharides?
A condensation reaction.
What kind of reaction can split the glycosidic bond in a disaccharide?
A hydrolysis reaction.
Define polysaccharide.
A chain of multiple monosaccharides joined by glycosidic bonds.
What are the three main types of polysaccharides?
Starch, cellulose, and glycogen.
What do starch and glycogen act as within cells, and why are they suitable for this?
Energy storage molecules because they have a low solubility in water, so they don’t affect the concentration of water in the cytoplasm of cells.
Which polysaccharide do plants use as a storage carbohydrate?
Starch.
What is starch composed of?
Amylose and amylopectin.
Why is cellulose known as a dietary fibre?
It is indigestible and aids the movement of material through the digestive tract.
Define triglyceride.
Molecules made up of three fatty acid molecules and one glycerol molecule linked by condensation reactions.
What is the name of the bond which joins a fatty acid and the glycerol in a triglyceride molecule?
An ester bond.
Define monounsaturated fats.
Fats which have one double bond between two of the carbon atoms in each fatty acid chain.
