Carbohydrates and Biomolecules

In glycolysis, glucose 6 phosphate is converted into fructose 6 phosphate.

Glucose is a reducing sugar whereas sucrose is a non-reducing sugar.

Cellobiose is a disaccharide composed of two glucose units linked via β(1→4) glycosidic linkage.

The repeating disaccharide unit in amylose is maltose.

Benedict's reagent is used as a test for the presence of reducing sugars. Sucrose is a non-reducing sugar; hence, it will NOT give a positive Benedict's test.

The sucrose molecule is a disaccharide composed of the monosaccharides glucose and fructose, bonded together by α(1→2)β glycosidic linkage.

Maltose or malt sugar is a disaccharide formed from two units of glucose. Lactose is a disaccharide sugar that is found most notably in milk and is formed from galactose and glucose.

Glycogen is a storage polysaccharide found in nearly all animal cells and in certain protozoa and algae.

Red algae yields algin, a gummy substance used to thicken cosmetics and food items like ice cream, jelly and chocolate. 

Glucose is the primary form of sugar absorbed into human blood from the digestive tract. During digestion, complex carbohydrates (starch, sucrose, maltose) are broken down into glucose by enzymes. Glucose then enters bloodstream through intestinal walls via active transport and diffusion. Sucrose (option A), maltose (option C), and starch (option D) are too large to be absorbed directly - they must first be converted to glucose.

Glucose is a monosaccharide, meaning it consists of a single sugar unit and cannot be broken down into simpler carbohydrates. Lactose and sucrose are disaccharides (two sugar units bonded together), while maltose is also a disaccharide formed from two glucose molecules.

Lactose is naturally present in mammalian milk and is commonly referred to as milk sugar. It is a disaccharide composed of glucose and galactose. Maltose is found in germinating grains, sucrose is common table sugar from plants, and glucose is a simple monosaccharide.

Monosaccharides are the simplest carbohydrates because they consist of a single sugar unit that cannot be hydrolyzed into smaller carbohydrates. Examples include glucose, fructose, and galactose. Disaccharides contain two monosaccharide units, while polysaccharides are long chains of many sugar units.

This option is correct because xylitol is a white odourless crystalline powder that has been used as a sweetening agent in food for over 40 years. The substance occurs naturally in many fruits and vegetables and sorbitol occurs naturally in various fruits and berries. First discovered in 1872, it is today commercially produced by the hydrogenation of glucose and is available in both liquid and crystalline forms. This pair represents natural sweeteners.

This option is correct because neotame is an artificial sweetener made by NutraSweet that is between 7000 and 13,000 times sweeter than sucrose. It is moderately heat-stable, extremely potent, rapidly metabolized, completely eliminated, and does not appear to accumulate in the body.