which is true of the process of digestion

ATI TEAS 7

ATI TEAS Science Test

1. Which statement is true regarding the process of digestion?

A. Digestion of starch begins in the mouth.
B. Amylase is produced by the stomach to help break down food in the upper intestine.
C. The di- and tri-saccharides produced in early digestion are absorbed through the intestinal wall.
D. Proteases are responsible for breaking down starches.

Correct answer: A

Rationale: The statement 'Digestion of starch begins in the mouth' is correct. Salivary amylase, an enzyme produced in the salivary glands, initiates the breakdown of starch into simpler sugars like maltose in the mouth before further digestion in the stomach. This initial breakdown of starch is crucial in the digestion of carbohydrates, marking the beginning of the digestive process. Choice B is incorrect because amylase is produced in the salivary glands, not the stomach. Choice C is incorrect because di- and tri-saccharides are further broken down into monosaccharides before absorption. Choice D is incorrect because proteases are enzymes that break down proteins, not starches.

2. In which regions of the digestive system is amylase produced?

A. pancreas and salivary glands
B. gall bladder and salivary glands
C. gall bladder and liver
D. pancreas and liver

Correct answer: A

Rationale: Amylase is an enzyme that breaks down carbohydrates into smaller sugars. It is produced in the pancreas and salivary glands. The salivary glands release amylase into the mouth during chewing, where it initiates the breakdown of carbohydrates. The pancreas also secretes amylase into the small intestine to further assist in carbohydrate digestion. Choices B, C, and D are incorrect as the gall bladder does not produce amylase, and the liver's primary function is not the production of amylase for carbohydrate breakdown.

3. A researcher is studying the response of bacteria to a certain chemical. In three experiments, the bacteria swim towards the chemical, and in one experiment, the bacteria swim away from it. What would be the most appropriate next step for the researcher?

A. Report only the first three experiments.
B. Report all the experiments, but refrain from making any conclusions.
C. Repeat the experiment several more times and apply a statistical analysis to the data.
D. Repeat the experiment, adding a new chemical to determine its effect on the bacteria.

Correct answer: C

Rationale: Repeating the experiment multiple times and applying statistical analysis would help ensure the results are reliable. By doing so, the researcher can validate the observed trends and determine the significance of the bacteria's response to the chemical. This approach would enhance the credibility of the findings and allow for more robust conclusions to be drawn. Reporting only the first three experiments (Choice A) would overlook critical data that could provide a comprehensive understanding of the bacteria's response. Refraining from making any conclusions (Choice B) would not utilize the available data effectively. Adding a new chemical in a repeated experiment (Choice D) would deviate from focusing on analyzing the response to the original chemical, introducing unnecessary variables.

4. Which type of energy is associated with the random motion of particles in a substance?

A. Potential energy
B. Mechanical energy
C. Thermal energy
D. Chemical energy

Correct answer: C

Rationale: Thermal energy is the correct answer as it is associated with the random motion of particles in a substance. When particles move randomly, they generate heat energy, which is a form of thermal energy. Potential energy is stored energy that can be converted into other forms when released, such as kinetic energy. Mechanical energy is the sum of potential and kinetic energy in an object, which is not directly related to the random motion of particles. Chemical energy is energy stored in the bonds of chemical compounds and is not specifically related to the motion of particles.

5. In the reaction 2Na + 2H2O → 2NaOH + H2, what is the limiting reactant when 3 moles of sodium react with 2 moles of water?

A. Na
B. H2O
C. NaOH
D. H2

Correct answer: A

Rationale: The balanced chemical equation indicates that 2 moles of sodium react with 2 moles of water to yield 2 moles of sodium hydroxide and 1 mole of hydrogen gas. When 3 moles of sodium react with only 2 moles of water, sodium becomes the limiting reactant as it is present in excess compared to the available water molecules. This situation arises because not all sodium atoms can fully react with the limited amount of water, resulting in sodium being the limiting reactant in this specific case. Choice B (H2O), choice C (NaOH), and choice D (H2) are incorrect as they are not the limiting reactant in the given reaction scenario.