Carbohydrates and Biomolecules

In nutritional science, 1 gram of carbohydrate provides approximately 4 kilocalories of energy. Proteins also provide 4 calories per gram, while fats provide 9 calories per gram. This standard conversion factor is used globally for food labeling and dietary calculations.

Statement C is the one that is not true. Both protein and carbohydrates provide 4 calories per gram, so 1 gram of protein has the same calories as 1 gram of carbs, not 2 grams. The other statements are generally true: alcohol does have empty calories (7 cal/g), brown bread typically has similar or slightly fewer carbs than white bread, and candies are primarily sugar, not fat-rich.

C6H12O6 is the molecular formula for glucose, a simple sugar and primary energy source in living organisms. Citric acid is C6H8O7, chloroform is CHCl3, and calcium is an element (Ca), not a compound with this formula. Glucose is fundamental to biology and metabolism.

Wax is a lipid (fat), not a carbohydrate. Sucrose, starch, and maltose are all carbohydrates - sucrose and maltose are disaccharides, starch is a polysaccharide. Waxes are esters of long-chain fatty acids with long-chain alcohols.

Glycogen is the complex polysaccharide stored in liver and muscle tissue as an energy reserve. It's the stored form of glucose, which the body can quickly break down when energy is needed. Glucose itself is a simple sugar (monosaccharide), not a complex storage form.

Glucose is the form in which carbohydrates circulate in the bloodstream. All digestible carbohydrates are ultimately broken down to glucose before entering circulation for delivery to cells. Maltose, galactose, and sucrose are disaccharides that must be broken down before transport.

Fructose is the sweetest naturally occurring sugar, about 1.2-1.8 times sweeter than sucrose (table sugar). It's found naturally in fruits and honey. Glucose and galactose are less sweet, while maltose (disaccharide) has mild sweetness.

Carbohydrates are biological molecules consisting of carbon, hydrogen, and oxygen in specific ratios, including starches and sugars. Protein is a macromolecule composed of amino acids, making it fundamentally different from carbohydrates. Chlorophyll is a pigment molecule involved in photosynthesis, also not a carbohydrate.

Saliva contains the enzyme salivary amylase (ptyalin) which breaks down starch into smaller carbohydrates. The process first produces dextrin (shorter starch chains) and then maltose (a disaccharide sugar). This is the first step of chemical digestion.

Table sugar (white sugar) is sucrose, a disaccharide composed of one glucose and one fructose molecule. Fructose is fruit sugar, galactose is found in milk, and glucose is blood sugar.

Table sugar (sucrose) is a disaccharide composed of glucose and fructose. Fructose is fruit sugar, galactose is found in milk, and glucose is blood sugar.

Lactose is the natural sugar found in milk, making up about 4-5% of cow's milk by weight. It is a disaccharide composed of glucose and galactose. Fructose is fruit sugar, sucrose is table sugar (from sugarcane or beets), and glucose is simple blood sugar.

Fructose is a natural sugar found in fruits, honey, and some vegetables. It is not chemically synthesized like artificial sweeteners. Acesulfame potassium, aspartame, and sucralose are all artificial sweeteners created through chemical synthesis to provide sweetness without calories. The question asks which one is NOT artificial, making fructose the correct choice.

Lactose is the sugar naturally found in milk and dairy products. Glucose is blood sugar, sucrose is table sugar from plants, and fructose is fruit sugar. Lactose is unique to milk as the primary carbohydrate.