Questions and Answers
Ingested dietary substances must cross cell membranes to be used by the body, a process known as _____.
absorption
Animals that migrate great distances would obtain the greatest energetic benefit of storing chemical energy as what?
fats
Why are certain nutrients considered 'essential' in the diets of some animals?
These animals are not able to synthesize these nutrients
What is an advantage of a complete digestive system over a gastrovascular cavity?
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In what order does a fasting animal draw on its stored resources?
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What do earthworms, grasshoppers, and birds all have?
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What is peristalsis in the digestive system?
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What happens upon activation by stomach acidity in the secretions of the parietal cells?
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What can constipation result from?
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After ingestion by humans, what is the first category of macromolecules to be chemically digested by enzymes in the mouth?
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What pH level is characteristic of the stomach's digestive secretions?
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What enzyme has high activity in an acidic environment?
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What enables adult lampreys to achieve nutritional balance without a stomach?
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What would a hiatal hernia most likely increase the frequency of?
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What is typical of rabbits, horses, and herbivorous bears?
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What nutrients are required by cells and obtained through food?
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What are the four classes of essential nutrients?
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What does undernourishment refer to?
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What is malnourishment?
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What are the four main stages of food processing?
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Define intracellular digestion.
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What is extracellular digestion?
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What characterizes a gastrovascular cavity?
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What is an alimentary canal?
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What is peristalsis?
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What do sphincters do?
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What is the purpose of the oral cavity?
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What is the role of salivary glands?
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What is the main function of teeth?
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What does salivary amylase do?
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What is the pharynx?
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What is the function of the epiglottis?
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What is the esophagus?
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What is the role of the stomach?
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What is HCl (hydrochloric acid) and its role?
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What is pepsin?
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What protects the lining of the stomach from self-digestion?
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What are gastric ulcers?
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What is the major organ of digestion and absorption?
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What is the duodenum?
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What are the digestive juices produced by the pancreas?
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What is absorption?
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What is elimination in the digestive context?
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What is digestion?
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What is ingestion?
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What is the difference between undernourishment and malnourishment?
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What must vegetarians do to obtain essential amino acids?
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Where is bile produced, and where is it stored?
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What are lacteals?
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What is bile's role in digestion?
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What are non-enzyme digestive secretions?
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What involves enzymes in digestion?
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What are the two types of digestion?
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What is the function of bile?
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Why does pepsin not function in the small intestine?
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Does stress cause ulcers?
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What do monosaccharides and amino acids do after moving into capillaries in the villi?
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How can dentition of a mammal's skull indicate its diet?
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What is a major function of the colon?
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What is the role of the cecum in grazing animals?
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How are fats absorbed?
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What makes up feces?
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What is digested by lipase and packed into chylomicrons?
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What is the role of leptin?
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What is leptin?
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What is obesity?
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What are the two functions of the small intestine?
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What is the human appendix and what is its role?
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What are essential amino acids?
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What do your symbiotic bacteria do for you?
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Which category of vitamin is most likely to result in an overdose?
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In humans, how is additional energy stored once liver and muscle cells are full?
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What keeps food from entering the lungs when we swallow?
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What health problems are related to obesity?
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What was reported in the 2005 Nobel Prize about the cause of ulcers?
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What is the pH of the stomach?
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How does the structure of the villi of the small intestine fit its function?
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Why do herbivores have longer alimentary canals than carnivores?
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What is the pH of the small intestine?
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What must animals obtain from the food they eat?
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What does bicarbonate do in the digestive system?
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What does mechanical digestion involve?
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Explain the role of insulin and glucagon in glucose homeostasis.
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Study Notes
Digestive Process and Nutrient Absorption
- Absorption is the process where ingested dietary substances cross cell membranes for body use.
- Essential nutrients cannot be synthesized by certain animals and must be obtained through diet.
- Fats are the most efficient way for animals that migrate long distances to store chemical energy.
- A complete digestive system allows for specialized functions in different regions.
Energy Utilization
- In fasting states, energy is drawn from stored resources in the order: liver glycogen, muscle glycogen, and then fat.
- Undernourishment results from a calorie-deficient diet; malnourishment occurs when one or more essential nutrients are missing.
Digestive Anatomy and Physiology
- Earthworms, grasshoppers, and birds possess a crop for food storage.
- Peristalsis refers to smooth muscle contractions that push food through the digestive tract.
- The stomach secretes gastric juices that initiate protein digestion and contain hydrochloric acid (pH 2), essential for pepsin activation.
- The mucosal lining of the stomach is protected from self-digestion by mucus.
Digestive Disorders and Functions
- Gastric ulcers can arise from infections by Helicobacter pylori.
- The small intestine is the major organ for digestion and absorption, with its first section (duodenum) engaging in significant chemical digestion.
Nutrient Classes and Their Functions
- Essential nutrients include essential amino acids, essential fatty acids, vitamins, and minerals that are crucial for cell function.
- Chemical digestion utilizes enzymes, while mechanical digestion involves physical processes like chewing and stomach churning.
Nutrient Pathways and Energy Storage
- Monosaccharides and amino acids are absorbed through the villi and travel to the liver via the hepatic portal vein for nutrient regulation and detoxification.
- Chylomicrons carry triglycerides from the intestine, facilitating fat absorption.
Role of Gut Flora and Vitamins
- Symbiotic bacteria produce vitamins in the gut that supplement dietary intake.
- Fat-soluble vitamins can lead to toxicity due to storage in body fat, while water-soluble vitamins are excreted through urine.
Digestive Processes Across Species
- Herbivores have longer alimentary canals compared to carnivores, providing more time for nutrient absorption due to the complexity of plant material.
- The appendix in humans has a minor role in immunity and is a remnant of larger digestive structures in herbivorous ancestors.
Homeostasis and Hormonal Regulation
- Insulin and glucagon from the pancreas regulate glucose levels and glycogen synthesis, ensuring glucose homeostasis.
- Leptin is a hormone that regulates appetite, helping to maintain body fat levels.
Health Risks and Related Conditions
- Obesity arises from overnourishment and is associated with various health issues including type 2 diabetes, cardiovascular diseases, and certain cancers.
- Dietary adaptations can be inferred from the dentation of mammals, indicating their feeding habits (carnivorous vs herbivorous).
Miscellaneous Facts
- Digestive secretions include bile, bicarbonate, and non-enzyme substances, aiding in digestion and maintaining pH levels in the intestine.
- The villi structure maximizes surface area for absorption in the small intestine, crucial for nutrient uptake.
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Description
Test your knowledge on Chapter 33 of AP Biology with these flashcards. This chapter covers important concepts such as nutrient absorption, energy storage in animals, and essential nutrients. Perfect for reviewing key terms and definitions.