Question 1

The unit of measure for the energy value of food is referred to as a calorie Actually, the caloric value of food is measured in _____ of calories

Accepted Answer

The caloric value of food is measured in thousands of calories or kilocalories (kcal). For example, a food item with a caloric value of 3000 would be written as 3000 kcal or 3,000 calories. The caloric value of food is measured in thousands of calories or kilo-calories (kcal). This is the most common unit used to describe the energy content of food. Option A, B, and D are incorrect as they are too small or too large to measure the caloric value of food accurately.

Question 2

The basic nutrients that comprise all foods and are necessary for the nutritional health of people are

Accepted Answer

Water, carbohydrates, proteins, lipids, vitamins, and minerals are the six basic nutrients that all foods contain and are necessary for the nutritional health of people.

Question 3

_____ dictates whether a substance is a solid, liquid, or gas

Accepted Answer

Molecular movement determines the state of matter of a substance. In a solid, the molecules are tightly packed and have very little movement. In a liquid, the molecules are more spread out and have some movement. In a gas, the molecules are very spread out and have a lot of movement.

Question 4

The amount of energy in calories per gram that is absorbed or emitted as a substance undergoes a change from a solid to a liquid or gas is called

Accepted Answer

The answer of The amount of energy in calories per...

Question 5

Which of the following statements does not describe a characteristic of bound water? Bound water is

Accepted Answer

Bound water is actually the smallest amount of water present in foods, as it is tightly bound to other molecules such as carbohydrates, lipids, and proteins. Free water is the largest amount of water present in foods. Bound water is the water that is chemically or physically associated with food constituents, such as proteins, carbohydrates, and lipids, and is not easily removed by normal processing or storage conditions. It is not necessarily the largest amount of water present in foods, and can vary depending on the type of food.

Question 6

Regarding boiling point, increasing the elevation

Accepted Answer

At higher elevations, there is less atmospheric pressure pushing down on the water molecules, which makes it easier for them to escape into the air as steam. Therefore, less heat is required to boil the water, resulting in a lower boiling point. As elevation increases, atmospheric pressure decreases. Since boiling point depends on atmospheric pressure, a decrease in pressure results in a lower boiling point. Therefore, at higher elevations, water boils at a lower temperature than it would at sea level.

Question 7

A partial gel in which only some of the solid particles colloidally dispersed in a liquid have solidified is called

Accepted Answer

A partial gel where only some of the dispersed solid particles have solidified is called flocculation. A suspension is a mixture in which small particles are distributed throughout a liquid but will eventually settle out, ionization refers to the process of forming ions from neutral molecules, and salt formation involves the combination of a base and an acid to form a salt. A partial gel with only some of the solid particles colloidally dispersed in a liquid having solidified is called a flocculation, as the solid particles have come together to form larger clusters or floccs but have not completely solidified into a gel. A suspension refers to a mixture in which solid particles are dispersed but not dissolved in a liquid. Ionization refers to the process of converting a molecule into ions. Salt formation refers to a chemical reaction in which an acid and a base react to form a salt and water.

Question 8

Which of the following food items is/are not a colloidal dispersion?

Accepted Answer

All of the above food items are colloidal dispersions.

Question 9

In foods, water has several functions, the two most important functions being

Accepted Answer

Water is crucial in foods for transferring heat during cooking processes and acts as a universal solvent, dissolving a wide range of substances.

Question 10

The building blocks of organic material include carbon, hydrogen, and oxygen plus

Accepted Answer

Nitrogen, phosphorus, and sulfur are commonly found in organic molecules such as nucleic acids, proteins, and essential amino acids. While some of the other minerals listed may also be present in organic compounds, they are not considered essential building blocks.

Question 11

Regarding measurement of water activity in a food, as free water decreases,

Accepted Answer

Water activity is the measure of free water available in a food. As the amount of free water decreases, water activity also decreases since there is less water available for microbial growth and other chemical reactions. Higher water activity is associated with increased microbial growth, so it is important to control water activity in foods to maintain their safety and shelf life. Water activity is a measurement of the availability of water molecules in a food, and as free water decreases, there are fewer available water molecules, and thus, a lower water activity. This is because water activity takes into account only the free water in the food, which is essential for microbial growth and chemical reactions. As the free water decreases, microbial growth and chemical reactions slow down, which results in a lower water activity.

Question 12

Which of the following food items is an example of a suspension?

Accepted Answer

Cornstarch mixed in water is an example of a suspension because it consists of solid particles that are dispersed throughout a liquid but do not dissolve, and they can settle out over time or can be separated by filtration.

Question 13

A pressure cooker speeds up heating time by _____

Accepted Answer

A pressure cooker works by increasing the atmospheric pressure inside the pot to around 15 pounds per square inch. This higher pressure allows the boiling point of water to increase from 212°F to around 250°F, thus speeding up the cooking process.

Question 14

The main purpose of eating and drinking is to replace those nutrients used up

Accepted Answer

Eating and drinking serve the purpose of replacing nutrients used up in the body's maintenance, repair, growth, and as a source of energy (calories). Therefore, all of the above answers are correct. Eating and drinking provide the body with nutrients for maintenance, repair, growth, and as a source of calories. All of these purposes are essential for keeping the body functioning properly.

Question 15

The caloric contribution of foods is dependent on the amounts of proteins, fats, carbohydrates, and alcohol in the food The kcal/g contributed by each of these substances, respectively, is

Accepted Answer

Proteins and carbohydrates each provide 4 kcal/g, fats provide 9 kcal/g, and alcohol provides 7 kcal/g.

Question 16

Which of the following is not an example of hydrolysis?

Accepted Answer

Hydrolysis of glucose to sucrose and maltose is not an example of hydrolysis because it involves the formation of a glycosidic bond between glucose and another sugar molecule, rather than the breakdown of a bond through the addition of water. Hydrolysis of glucose to sucrose and maltose is not an example of hydrolysis because it involves the condensation of two monosaccharides to form a disaccharide, rather than the breakdown of a larger molecule into smaller components through the addition of water molecules.

Question 17

Which of the following foods contains the highest percentage of water?

Accepted Answer

Baked potato contains approximately 70-80% water, which is the highest percentage of water among the given food choices.

Question 18

The human body averages _____ percent water

Accepted Answer

The human body averages about 60 to 70 percent water.

Question 19

Hard water contains a greater concentration of calcium and magnesium compounds, whereas soft water has a higher _____ concentration

Accepted Answer

Soft water typically has a higher concentration of sodium ions instead of calcium and magnesium ions found in hard water.

Question 20

Which of the following substances is/are not used in the food industry to reduce a food's water activity (aw) level?

Accepted Answer

All of these substances (salt, sugar, glycerol, propylene glycol, and modified corn syrups) are commonly used in the food industry to reduce a food's water activity level. All of the substances listed (salt, sugar, glycerol, propylene glycol, and modified corn syrups) are commonly used by the food industry to reduce a food's water activity (aw) level.

Quiz 3: Chemistry of Food Composition