An amino acid that we cannot synthesize and must be in our diet is a) DNa. b) ad

Question

An amino acid that we cannot synthesize and must be in our diet is a) DNa. b) adenosine triphosphate. c) an essential amino acid. d) an enzyme. e) a vitamin. 2) An animal's diet provides a) Chemical energy to power cellular processes b) Organic building blocks to synthesize a variety of organic molecules. c) Essential nutrients, which are required by cells and must be obtained from dietary sources d) all of the above e) none of the above Which of the following is a function of human saliva? a) Acidifying food. b) Digesting proteins. c) Emulsifying fats. d) Digesting nucleic acids. e) Starting the digestion of starch. Sphincters a) are the accessory glands of the digestive system. b) are found only in animals with gastrovascular cavities. c) secrete digestive juices. d) regulate the movement of material between compartments of the digestive tract. e) are needed for extracellular digestion only. The chief cells of the gastric glands of the human stomach a) secrete pepsinogen. b) increase the membrane potential of the stomach. c) move food upward in the stomach to prolong digestion. d) produce hydrochloric acid. e) lubricate and protect the stomach lining. Chemical digestion of protein starts in the a) small intestine b) liver c) large intestine d) pancreas. e) stomach. Fats are emulsified, digested, and absorbed in the a) stomach. b) colon. c) small intestine. d) appendix. e) esophagus. The hepatic portal vein carries blood from the _____ to the _____. a) intestine... heart b) intestine ... liver c) liver ... heart d) stomach ... heart e) heart ... liver A main function of the colon is a) water absorption b) protein digestion c) fat absorption d) mechanical digestion e) starch digestion Vertebrates, annelids, and cephalopods have a) an open circulatory system. b) a closed circulatory system. c) a gastrovascular cavity. d) no circulatory system. e) none of the above. Which of the following animals has a single circuit of blood flow? a) chicken b) salmon c)squirrel d) frog e) lizard During ventricular systole, a) the atria fill with blood from the ventricles b) the AV values are closed c) the cardiac muscle relaxes d) the semilunar valves are closed e) the ventricles fill with blood The _____ sets the rate at which cardiac muscle cells contract. a) aorta. b) vena cava. c) semilunar valves. d) sinoatrial node. e) capillaries. Which blood vessels have the thinnest walls? a) arteries b) capillaries c) venules d) veins e) arterioles.

Explanation / Answer

1 essential amino acid

2. all of the above

3 starting digestion of starch

4 spincters regulate movement of food d)

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.