Nokea
How many different amino acids make up human proteins?
- A. 9
- B. 13
- C. 15
- D. 20
Correct Answer: D
Rationale: The correct answer is D: 20. There are 20 different amino acids that combine to form proteins in the human body. Each amino acid has a unique side chain that determines its properties. Choices A, B, and C are incorrect as they do not represent the total number of different amino acids found in human proteins.
You may also like to solve these questions
The end products of digestion of macronutrients include fatty acids, amino acids, and:
- A. monosaccharides.
- B. polysaccharides.
- C. enzymes.
- D. cholesterol.
Correct Answer: A
Rationale: The correct answer is A: monosaccharides. When macronutrients like carbohydrates are digested, they are broken down into simpler forms. Carbohydrates are broken down into monosaccharides, proteins into amino acids, and fats into fatty acids. Therefore, the end products of carbohydrate digestion are monosaccharides. Choices B, C, and D are incorrect because polysaccharides are larger carbohydrate molecules, enzymes are not the end products of digestion but rather aid in the process, and cholesterol is not a direct end product of macronutrient digestion.
What is the process by which proteins are synthesized from the available amino acids?
- A. Gluconeogenesis.
- B. Deamination.
- C. Protein synthesis.
- D. Transamination.
Correct Answer: C
Rationale: The correct answer is C: Protein synthesis. This process involves the formation of proteins from amino acids to support various body functions. Gluconeogenesis (choice A) is the synthesis of glucose from non-carbohydrate sources, not protein synthesis. Deamination (choice B) is the removal of an amino group from an amino acid, not the synthesis of proteins. Transamination (choice D) is the transfer of an amino group from one molecule to another, not the direct synthesis of proteins.
The interrelated network of nerves within the gastrointestinal wall that regulates its muscular action is known as the:
- A. gastric nerve plexus.
- B. biliary nerve plexus.
- C. intramural nerve plexus.
- D. intestinal nerve plexus.
Correct Answer: C
Rationale: The correct answer is C - intramural nerve plexus. This network of nerves regulates the muscular movements within the gastrointestinal wall. The gastric nerve plexus (choice A) specifically relates to the stomach, not the entire gastrointestinal tract. The biliary nerve plexus (choice B) is associated with the bile ducts and gallbladder, not the regulation of muscular action. The intestinal nerve plexus (choice D) is a general term that doesn't specifically refer to the network of nerves within the gastrointestinal wall.
After absorption, the end products of carbohydrate and protein digestion enter the:
- A. enterohepatic circulation.
- B. gastrointestinal circulation.
- C. common bile duct.
- D. portal blood system.
Correct Answer: D
Rationale: The correct answer is D: portal blood system. After absorption, carbohydrates and proteins are transported via the portal blood system to the liver for further processing and distribution to the rest of the body. Choices A, B, and C are incorrect. Enterohepatic circulation refers to the recycling of compounds between the liver and the intestines, not the direct route for absorbed nutrients. Gastrointestinal circulation is a vague and non-specific term, not specifically related to the transport of absorbed nutrients. The common bile duct is involved in transporting bile from the liver and gallbladder to the small intestine, not the end products of carbohydrate and protein digestion.
What substance acts as an emulsifier and helps absorb digested fat?
- A. bile
- B. trypsin
- C. lipase
- D. cholecystokinin (CCK)
Correct Answer: A
Rationale: The correct answer is A: bile. Bile acts as an emulsifier, breaking down fats into smaller droplets to aid in digestion and absorption. Trypsin is a digestive enzyme that acts on proteins, not fats. Lipase is an enzyme that breaks down fats, but it doesn't act as an emulsifier. Cholecystokinin (CCK) is a hormone that stimulates the release of digestive enzymes, including lipase, but it is not directly involved in emulsification.