Nutrition Module 8.1: Digestive System and Essential Fatty Acids

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Questions and Answers

What is the main function of essential nutrients in an animal's diet?

To synthesize macromolecules from simpler organic molecules

To provide energy for cellular processes

To maintain homeostatic balance

To catalyze biosynthesis reactions (correct)

Which of the following is NOT a class of essential nutrients?

Vitamins

Essential fatty acids

Essential amino acids

Proteins (correct)

What is a characteristic of fat-soluble vitamins?

They are essential for humans

They are synthesized by the body

They are required in large amounts

They are insoluble in water (correct)

What is the term for a failure to obtain adequate nutrition?

Malnutrition Signup and view all the answers

How many amino acids do animals require from their diet?

20 Signup and view all the answers

What is the term for animals that eat both plants and animals?

Omnivores Signup and view all the answers

What is the primary concern when individuals consume only plant proteins?

They may not get all the essential amino acids Signup and view all the answers

What is the benefit of consuming Golden Rice?

It is converted into Vitamin A in the body Signup and view all the answers

What is the process called when food particles are engulfed by phagocytosis?

Intracellular Digestion Signup and view all the answers

What is the term for the breakdown of food particles outside of cells?

Extracellular Digestion Signup and view all the answers

What is the result of a deficiency in essential nutrients?

Deformities, disease, and death Signup and view all the answers

What type of body plan is associated with a gastrovascular cavity?

Simple body plan Signup and view all the answers

What is the primary function of salivary glands in the mammalian digestive system?

To secrete digestive juices through ducts Signup and view all the answers

Which type of feeder sifts small food particles in water?

Suspension Feeders Signup and view all the answers

What is the term for the rhythmic contractions of muscles in the wall of the alimentary canal?

Peristalsis Signup and view all the answers

What is the term for the passage of undigested material out of the digestive system?

Elimination Signup and view all the answers

Which type of feeder eats relatively large pieces of food?

Bulk Feeders Signup and view all the answers

What is the term for the valves that regulate the movement of material between compartments in the alimentary canal?

Sphincters Signup and view all the answers

What is the primary function of the parietal cells in the stomach?

To secrete hydrogen and chloride ions into the stomach cavity Signup and view all the answers

What is the result of the swallowing reflex failing and food or liquids reaching the trachea?

Coughing occurs to expel the food or liquids from the trachea Signup and view all the answers

What is the name of the disease that occurs when gastric juices from the stomach flow back into the esophagus?

Gastroesophageal reflux disease (GERD) Signup and view all the answers

What is the function of the sphincters in the stomach?

To regulate the entry of chyme into the small intestine Signup and view all the answers

What is the name of the process by which the esophagus conducts food to the stomach?

Peristalsis Signup and view all the answers

What is the name of the enzyme that is secreted by chief cells in the stomach and breaks down proteins into smaller peptides?

Pepsinogen Signup and view all the answers

What is the primary function of the colon in the digestive system?

To reabsorb water and electrolytes from the waste material Signup and view all the answers

What is the role of the appendix in the human body?

It plays a minor role in immunity and aids in the digestion of cellulose Signup and view all the answers

Which of the following hormones suppresses appetite and plays a role in regulating body fat levels?

Leptin Signup and view all the answers

What is the primary function of the ruminant digestive system?

To ferment cellulose in plant material Signup and view all the answers

Which of the following systems helps to regulate the digestive process?

The enteric division of the nervous system Signup and view all the answers

What is the primary source of carbon skeletons for biosynthesis in the human body?

Glucose Signup and view all the answers

Study Notes

Nutrition

Essential fatty acids must be obtained from the diet and include certain unsaturated fatty acids.
Animals can synthesize most fatty acids needed, but deficiencies in fatty acids are rare.
Vitamins are organic molecules required in the diet in very small amounts, with 13 essential vitamins for humans.
There are two categories of vitamins: fat-soluble and water-soluble.
An animal's diet must provide chemical energy for cellular processes, organic building blocks for macromolecules, and essential nutrients.

Essential Nutrients

Essential nutrients are materials that an animal cannot assemble from simpler organic molecules.
There are four classes of essential nutrients: essential amino acids, essential fatty acids, vitamins, and minerals.
Essential amino acids are required by animals and must be obtained from food preassembled.
Meat, eggs, and cheese provide all the essential amino acids and are thus "complete" proteins.
Deficiencies in essential nutrients can cause deformities, disease, and death.

The Digestive Process

Intracellular digestion involves the breakdown of food particles inside cells.
Extracellular digestion occurs outside of cells in compartments continuous with the outside of the animal's body.
The alimentary canal is a digestive tube with two openings, seen in more complex animals.
The stages of food processing are ingestion, digestion, absorption, and elimination.
Strategies for extracting resources include suspension feeding, substrate feeding, fluid feeding, and bulk feeding.

The Mammalian Digestive System

The mammalian digestive system consists of an alimentary canal and accessory glands that secrete digestive juices.
The accessory glands include salivary glands, pancreas, liver, and gallbladder.
Food is pushed along by peristalsis, rhythmic contractions of muscles in the wall of the canal.
Sphincters are valves that regulate the movement of material between compartments.

Chemical Digestion in the Stomach

Gastric juice has a low pH of about 2, which kills bacteria and denatures proteins.
Pepsin cleaves proteins into smaller peptides.
Parietal cells secrete hydrogen and chloride ions separately into the stomach cavity.
Chief cells secrete inactive pepsinogen, which is activated to pepsin when mixed with HCI in the stomach.

The Small Intestine

The small intestine is the longest compartment of the alimentary canal.
It is where most nutrient absorption occurs.
The human cecum has an extension called the appendix, which plays a minor role in immunity.
Herbivores have fermentation chambers, where mutualistic microorganisms digest cellulose.

Regulation of Digestion

Each step in the digestive system is activated as needed.
The enteric division of the nervous system helps to regulate the digestive process.
The endocrine system also regulates digestion through the release and transport of hormones.
Insulin and PYY are hormones secreted by the small intestine after meals, which suppress appetite.
Leptin is produced by adipose tissue, which suppresses appetite and plays a role in regulating body fat levels.

Glucose Homeostasis

Glucose is a major fuel for cellular respiration and a key source of carbon skeletons for biosynthesis.
Insulin and glucagon are hormones that regulate the breakdown of glycogen into glucose.

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Description

Learn about the process of digestion and the importance of essential fatty acids in the diet. Discover how animals synthesize fatty acids and their roles in the body.