Question 1

Probiotics are live microorganisms that, when consumed in adequate amounts, confer a health benefit on the host, but prebiotics are non- digestible starch found in plant foods that promotes the growth and health of your GI flora.

Accepted Answer

Probiotics are indeed live microorganisms that offer health benefits when consumed in proper amounts, primarily by improving or restoring the gut flora. Prebiotics, on the other hand, are types of dietary fiber that feed the friendly bacteria in the gut, helping them to grow and flourish, but they are not limited to non-digestible starches and can be found in a wide range of dietary fibers.

Question 2

Peristalsis is repeated waves of contractions of circular muscles which prevent food from moving backward in the esophagus, but segmentation in the small and large intestines shifts food back and forth along the intestinal walls.

Accepted Answer

Peristalsis involves rhythmic contractions that move food through the digestive tract, preventing backward movement, while segmentation in the intestines mixes food with digestive juices and aids in nutrient absorption by moving it back and forth.

Question 3

Food is propelled through the GI tract by weak and gentle muscular contractions.

Accepted Answer

Food is propelled through the GI tract by a series of strong and rhythmic muscular contractions known as peristalsis.

Question 4

The excretory system filters blood and eliminates waste material.

Accepted Answer

The excretory system's primary function is to remove waste and excess substances from the bloodstream, maintaining the body's internal environment.

Question 5

Many enzymes are proteins catalyze chemical reactions, and remain unchanged by the reactions.

Accepted Answer

Enzymes are proteins that act as catalysts to speed up chemical reactions without being consumed or permanently altered by the reaction.

Question 6

During hydrolysis of sucrose, a molecule of sucrose (sugar) is digested by the enzyme sucrase when it breaks the bond with the addition of water by adding a hydroxyl group (OH) to form glucose and hydrogen (H) to form fructose.

Accepted Answer

During hydrolysis, sucrase breaks the glycosidic bond in sucrose by adding a water molecule, resulting in glucose and fructose, with OH added to one and H to the other.

Question 7

Wavelike muscular contractions throughout the GI tract propel food and liquid forward by the coordinated action among muscles, nerves, and hormones in the GI tract

Accepted Answer

This process is known as peristalsis, which is essential for moving food through the digestive system.

Question 8

Sucrase hydrolyzes the sugar sucrose, and maltase hydrolyzes maltose.

Accepted Answer

Sucrase and maltase are enzymes that catalyze the hydrolysis of sucrose and maltose into their constituent monosaccharides, respectively.

Question 9

Each enzyme needs a specific substrate or nutrients, pH, and optimal temperature in order to function optimally.

Accepted Answer

Enzymes are highly specific catalysts that require particular substrates or nutrients, and they have optimal pH and temperature ranges at which they function most efficiently. This specificity and requirement for certain conditions are crucial for the proper functioning of biochemical processes in living organisms.

Question 10

Saliva, gastric juices, bile, and bicarbonate contribute to the optimal environment for absorption to occur.

Accepted Answer

The answer of Saliva, gastric juices, bile, and bicarbonate contribute...

Question 11

Clara is a healthy college student who eats reasonably well and has not been sick for several years. She therefore digests and absorbs 92- 97 percent of the nutrients in her foods.

Accepted Answer

Healthy individuals, especially those with a balanced diet and without digestive issues, typically have high nutrient absorption rates, often estimated between 85% to 90% for macronutrients and can be higher for certain micronutrients, making 92-97% a plausible range for some nutrients.

Question 12

When food enters the stomach, the parietal cells produce hydrochloric acid (HCl) and a protein called intrinsic factor.

Accepted Answer

Parietal cells in the stomach lining produce hydrochloric acid (HCl), which helps in digestion and sterilization of food, and intrinsic factor, which is essential for the absorption of vitamin B12 in the small intestine.

Question 13

Passive diffusion, facilitated diffusion, active transport, or endocytosis facilitate nutrient absorption at the brush border of the small intestine.

Accepted Answer

These mechanisms are involved in nutrient absorption in the small intestine, where passive diffusion allows nutrients to move along their concentration gradient, facilitated diffusion uses carrier proteins for nutrient transport, active transport requires energy to move nutrients against their concentration gradient, and endocytosis involves the cell membrane engulfing substances to bring them into the cell.

Question 14

The only site for absorption of water is the small intestine.

Accepted Answer

Water is primarily absorbed in the small intestine, but significant absorption also occurs in the large intestine (colon).

Question 15

The endocrine and nervous systems are responsible for coordinating digestion, absorption, and elimination.

Accepted Answer

The endocrine and nervous systems work together to regulate digestion, absorption, and elimination by coordinating the functions of different organs and tissues involved in these processes.

Question 16

When the food you eat reaches your stomach, endocrine glands release gastric hormones to signal the rest of the GI tract to prepare for digestion.

Accepted Answer

Endocrine glands in the stomach release gastric hormones, such as gastrin, which signal various parts of the gastrointestinal (GI) tract and other organs to prepare for and aid in the digestion process.

Question 17

The enterogastrones gastrin, secretin, cholecystokinin, and gastric inhibitory peptide regulate digestion by stimulating or inhibiting the release of secretions from the stomach, small intestine, pancreas, and gallbladder.

Accepted Answer

Gastrin, secretin, cholecystokinin, and gastric inhibitory peptide are all enterogastrones that regulate digestion by stimulating or inhibiting the release of secretions from the stomach, small intestine, pancreas, and gallbladder.

Question 18

Ghrelin and peptide YY communicate with the brain to help you decide when to eat and when to stop eating.

Accepted Answer

Ghrelin stimulates appetite, signaling the brain to eat, while peptide YY decreases appetite, signaling when to stop eating.

Question 19

The enteric nervous system is a network of nerves embedded in the wall of the GI tract. It functions both autonomously and in collaboration with the central nervous system and other nervous system branches to achieve GI functions.

Accepted Answer

The enteric nervous system (ENS) is indeed a complex network of neurons embedded in the gastrointestinal (GI) tract's wall, functioning autonomously but also interacting with the central nervous system (CNS) and other parts of the nervous system to regulate digestive processes.

Question 20

Water- soluble and fat- soluble nutrients are transported from the lymph capillaries through the lymphatic vessels and eventually arrive at the thoracic duct.

Accepted Answer

The answer of Water- soluble and fat- soluble nutrients are...

Quiz 3: Digestion, Absorption, and Transport