Human Anatomy and Physiology : Help with Digestive Enzymes and Hormones

Study concepts, example questions & explanations for Human Anatomy and Physiology

varsity tutors app store varsity tutors android store

Example Questions

← Previous 1

Example Question #1 : Help With Digestive Enzymes And Hormones

Which of the following enzymes secreted by the pancreas is necessary in order to activate all remaining enzymes secreted into the small intestine?

Possible Answers:

Lipase

Ribonuclease

Chymotrypsin

Trypsin

Correct answer:

Trypsin

Explanation:

All enzymes released into the lumen of the small intestine by the pancreas are zymogens. Enterokinase is an enzyme that activates trypsin in the lumen. Once trypsin is activated, it is capable of activating every other enzyme found in the lumen of the small intestine, even other trypsin enzymes.

Example Question #2 : Help With Digestive Enzymes And Hormones

What is the purpose of bile in the small intestine?

Possible Answers:

Fat digestion

Fat emulsification

Carbohydrate digestion

Lowers the acidity of chyme

Correct answer:

Fat emulsification

Explanation:

Bile is produced by the liver and released from the gall bladder into the small intestine. It has the function of emulsifying fat, increasing its surface area by forming micelles. This allows the protein lipase to break down and digest the fat in the small intestine much more quickly.

The pancreas secretes bicarbonate to neutralize the acidity of chyme and pancreatic amylase to aid in the digestion of carbohydrates.

Example Question #2 : Help With Digestive Enzymes And Hormones

Which of the following sections of the digestive system is NOT involved in chemical digestion?

Possible Answers:

Esophagus

Small intestine

Stomach

Mouth

Correct answer:

Esophagus

Explanation:

The mouth, stomach, and small intestine all contain enzymes that help chemically digest food. The mouth contains salivary amylase to digest carbohydrates. The stomach contains pepsin to digest proteins. The small intestine contains numerous enzymes from pancreatic secretions that digest carbohydrates, fats, and proteins.

The esophagus serves to transport food from the mouth to the stomach via smooth muscle contractions. No chemical digestion takes place in the esophagus, and no digestive enzymes are secreted into this region.

Example Question #4 : Help With Digestive Enzymes And Hormones

Which term refers to the waves of muscular contractions that propel consumed nutrients through the digestive tract?

Possible Answers:

Mastication

Peristalsis

Segmentation contractions

Pendular movements

Churning movements

Correct answer:

Peristalsis

Explanation:

Peristalsis is the rhythmic contraction of smooth muscle to propel digested contents through the digestive tract. It is most commonly examined in the esophagus, as the means by which a bolus is transported from the mouth to the stomach.

Segmentation contractions occur in the small intestine as a means of mixing chyme with digestive enzymes, but do not result in propulsion. Churning movements are most common in the stomach, where food particulates are mechanically digested and exposed to hydrochloric acid. Mastication refers to the mechanical digestion of food via crushing and tearing, primarily achieved when food is chewed in the mouth.

Example Question #3 : Help With Digestive Enzymes And Hormones

Which of the following enzymes causes contraction of the gall bladder in order to release bile?

Possible Answers:

Trypsin

Secretin

Carboxypeptidase

Cholecystokinin

Pepsin

Correct answer:

Cholecystokinin

Explanation:

Cholecystokinin causes the gall bladder to contract so that it can releae bile into the small intestine.

Secretin is released in response to acid in the small intestine, and causes a release of pancreatic bicarbonate to neutralize the acid. Pepsin, trypsin, and carboxypeptidase are all involved in chemical digestion of proteins.

Example Question #4 : Help With Digestive Enzymes And Hormones

In the stomach, which enzyme is responsible for the digestion of protein?

Possible Answers:

Trypsin

Kinase

Amylase

Trypsinogen

Pepsin

Correct answer:

Pepsin

Explanation:

15% of protein digestion occurs in the stomach and pepsin is the enzyme responsible. Remember, pepsin has an optimum pH of about 2.0, which is the pH of the stomach. Trypsin, another protease, has an optimum pH of 7.5-8.5, and therefore would not function in the stomach. Rather, it is produced by the pancreas and carries out its enzymatic reaction in the small intestine. Amylase breaks down carbohydrates. Trypsinogen is the inactive form of trypsin, thus it does not directly break down proteins.

Example Question #7 : Help With Digestive Enzymes And Hormones

Which of the following are not secreted by the pancreas?

Possible Answers:

Pepsin

Bicarbonate

Lipase

Trypsin

Amylase

Correct answer:

Pepsin

Explanation:

The pancreas is responsible for secreting digestive enzymes into the small intestine. These enzymes are responsible for digesting lipids (lipase), proteins (trypsin), nucleic acids (nucleases), and starches (amylase). In addition, the pancreas secretes bicarbonate to help neutralize the acids coming from the stomach. Pepsin's zymogen, pepsinogen is released by chief cells in the stomach, and gets activated by the acid that is also produced by the stomach (by parietal cells).

Example Question #8 : Help With Digestive Enzymes And Hormones

Which of the following is secreted in active form?

Possible Answers:

None of these

Trypsin

Pepsin

Angiotensin

Amylase

Correct answer:

Amylase

Explanation:

Amylase is secreted in active form. Pepsin and trypsin are first secreted as zymogens, inactive precursors that must be activated in order to function. Zymogens are produced with peptides blocking their active sites that must first be cleaved to function. Angiotensin is also secreted as a zymogen, angiotensinogen. Zymogens are useful in allowing the body to quickly activate an enzyme/hormone rather than synthesizing it from scratch.

Example Question #9 : Help With Digestive Enzymes And Hormones

Which of the following is correctly matched with its approximate optimum pH?

Possible Answers:

Trypsin: 4.0

Pepsin: 9.0

Amylase: 7.0

Pancreatic lipase: 4.0

Trypsin: 3.0

Pepsin: 2.0

Amylase: 2.5

Pancreatic lipase: 3.5

Trypsin: 8.0

Pepsin: 2.0

Amylase: 7.0

Pancreatic lipase: 8.0

Trypsin: 8.0

Pepsin: 8.0

Amylase: 7.0

Pancreatic lipase: 8.0

Trypsin: 1.0

Pepsin: 9.0

Amylase: 10.0

Pancreatic lipase: 8.0

Correct answer:

Trypsin: 8.0

Pepsin: 2.0

Amylase: 7.0

Pancreatic lipase: 8.0

Explanation:

The body compartmentalizes each hormone to help ensure it is it its optimum pH. Try to remember where each enzyme functions to help remember each enzyme's optimum pH. Pancreatic amylase is secreted by the pancreas into the small intestine. Amylase also occurs in the mouth, which is neutral. It's optimum is around 7. Pancreatic lipase is secreted by the pancreas into the small intestine, which is slightly basic because of the release of bicarbonate. Pancreatic lipase functions best at a pH of about 8. Trypsin is also secreted by the pancreas into the small intestine, and has an optimal pH of about 8. Pepsin functions in the stomach, which is extremely acidic. Pepsin's optimum pH is about 2.

 

Example Question #10 : Help With Digestive Enzymes And Hormones

Correctly identify the changes in the levels of the following hormones and molecules in the body just after a person has eaten.

Possible Answers:

Insulin decreases, glycogen decreases, glucagon decreases, and the liver releases more glucose.

Insulin increases, glycogen increases, glucagon decreases, and the liver releases more glucose.

Insulin increases, glycogen decreases, glucagon decreases, and the liver releases more glucose.

Insulin decreases, glycogen increases, glucagon increases, and the liver releases less glucose.

Insulin increases, glycogen increases, glucagon decreases, and the liver releases less glucose.

Correct answer:

Insulin increases, glycogen increases, glucagon decreases, and the liver releases less glucose.

Explanation:

Just after eating, the body is busily converting carbon-based life forms to glucose. If the body is about to have an influx of glucose, the the body must produce more insulin to allow for the passage of glucose into its cells. Glycogen, the stored form of glucose, would naturally increase since the person just replenished lost glucose or energy with food and will store it for later use. Glucagon would decrease because this breaks down glycogen. If the body is receiving fresh glucose, it doesn't need to break down its stores of glycogen into glucose. And finally, if the body is breaking down food into glucose, the liver doesn't need to release more freshly broken down (glucose that was previously stored as glycogen) glucose.

← Previous 1
Learning Tools by Varsity Tutors

Incompatible Browser

Please upgrade or download one of the following browsers to use Instant Tutoring: