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Which nutrients can be absorbed without first being digested in the human gastrointestinal tract?

A. carbohydrates and polypeptides

B. proteins and vitamins

C. minerals and polysaccharides

D. vitamins and minerals

Answer Explanation:

D) vitamins and minerals

- Correct: Vitamins and minerals are nutrients that can be absorbed without first being digested in the human gastrointestinal tract. Unlike carbohydrates, proteins, and fats, which require enzymatic digestion to break them down into smaller molecules for absorption, vitamins and minerals are already in a form that can be readily absorbed by the body. Once absorbed, vitamins and minerals play essential roles in various physiological processes, such as metabolism, immune function, and bone health.

A) carbohydrates and polypeptides

- Incorrect: Carbohydrates and polypeptides (large protein molecules) require enzymatic digestion to break them down into simpler molecules (such as glucose from carbohydrates and amino acids from polypeptides) before they can be absorbed by the gastrointestinal tract.

B) proteins and vitamins

- Incorrect: Proteins require enzymatic digestion to break them down into amino acids before they can be absorbed by the gastrointestinal tract. While vitamins do not require digestion and can be directly absorbed, proteins do not fall into this category.

C) minerals and polysaccharides

- Incorrect: Minerals, such as calcium, iron, and zinc, can be directly absorbed without prior digestion in the gastrointestinal tract. However, polysaccharides (complex carbohydrates) require enzymatic digestion into simpler sugars before they can be absorbed.

Therefore, the Correct Answer is D.

More Questions on TEAS 7 Science

  • Q #1: A source of roughage in the human diet is supplied by certain

    A. saturated lipids

    B. complete proteins

    C. complex carbohydrates

    D. nucleic acids

    Answer Explanation

    C) complex carbohydrates

    - Correct: Complex carbohydrates, such as whole grains, legumes, fruits, and vegetables, are sources of roughage in the human diet. Roughage, also known as dietary fiber, refers to the indigestible portion of plant foods that adds bulk to the stool and promotes healthy digestion. Complex carbohydrates contain both soluble and insoluble fiber, which helps regulate bowel movements, prevent constipation, and promote overall digestive health.

    A) saturated lipids

    - Incorrect: Saturated lipids, commonly found in animal fats and some plant oils, are not sources of roughage. While they are a component of the diet and provide energy, they do not contribute to the fiber content of the diet.

     

    B) complete proteins

    - Incorrect: Complete proteins, which contain all essential amino acids, are not sources of roughage. Proteins are important for building and repairing tissues, as well as for various physiological functions, but they do not provide dietary fiber.

    D) nucleic acids

    - Incorrect: Nucleic acids, such as DNA and RNA, are not sources of roughage. They are essential molecules involved in genetic information transfer and protein synthesis but are not related to the fiber content of the diet.

  • Q #2: The pancreas is an organ connected to the digestive tract of humans by a duct (tube) through which digestive enzymes flow. Why are these enzymes important to the digestive system?

    A. They form proteins needed in the stomach.

    B. They form the acids that break down food.

    C. They change food substances into molecules that can pass into the bloodstream and cells.

    D. They change food materials into wastes that can be passed out of the body.

    Answer Explanation

    C) They change food substances into molecules that can pass into the bloodstream and cells.

    - Correct: Digestive enzymes secreted by the pancreas play a crucial role in breaking down complex food molecules into smaller, absorbable molecules that can pass through the walls of the small intestine and into the bloodstream. These smaller molecules include carbohydrates broken down into simple sugars, proteins broken down into amino acids, and fats broken down into fatty acids and glycerol. Once these molecules are absorbed into the bloodstream, they can be transported to cells throughout the body to provide energy and support various metabolic processes.

    A) They form proteins needed in the stomach.

    - Incorrect: Digestive enzymes do not form proteins needed in the stomach. Proteins are broken down into amino acids by digestive enzymes, but the enzymes themselves do not form proteins.

    B) They form the acids that break down food.

    - Incorrect: Digestive enzymes do not form acids. Acids such as hydrochloric acid are secreted by the stomach and aid in the breakdown of food, particularly proteins, but they are not formed by pancreatic enzymes.

    D) They change food materials into wastes that can be passed out of the body.

    - Incorrect: While digestive enzymes help break down food materials, their primary function is to convert these materials into absorbable molecules rather than wastes. The conversion of food into waste products occurs primarily through processes in the digestive tract and is facilitated by enzymes as part of digestion, but it is not the direct role of pancreatic enzymes.

  • Q #3: Which process is represented by the diagram below?

    A. emulsification

    B. excretion

    C. absorption

    D. peristalsis

    Answer Explanation

    Emulsification is a process by which large fat globules are broken down into smaller droplets. This process is facilitated by substances called emulsifiers, with bile being one of the most common emulsifiers in the human body.