Learning Objectives 2 Animal Digestion

1. Herbivores and omnivores- longer alimentary canals than carnivores
2. Microorganisms help herbivores digest plants
3. Mutualistic bacteria and protists in fermentation chambers of vertebrates have enzymes that digest things such as cellulose to simple sugars, etc.

1. Type 1- usually from birth, body does not produce insulin
2. Type 2- usually developed, body does not react properly to insulin and glucagon

1. Saliva
2. Tongue

Complete Digestion Tract/Alimentary Canal Food moves along in a single direction, tube can be organized into specialized compartments which carry out digestion and nutrient absorption in stepwise fashion Animals can ingest food while earlier meals are still being digested Gastrovascular Cavity Compartment with a single opening-pouch Most hydrolysis happens internally and undigested materials remain in cavity, usually excreted the same opening by which food entered Cannot eat more when food is still being digested Name three functions of saliva and three functions of the tongue

1. Amylase-hydrolyzes starch and glycogen into smaller polysaccharides
2. Mucin- lubricates food for easier swallow and protects lining of mouth
3. Additional components- buffers preventing tooth decay, antibacterial agents

1. Hydrolysis of food inside vacuoles
2. Cells engulfs solid food by phagocytosis or liquid food by pinocytosis
3. Newly formed vacuoles fuse with lysosomes with brings food together with enzymes so digestion can occur within protective membranes

1. Excesses of water-soluble vitamins are excreted in urine.
2. Excesses of fat-soluble vitamins are deposited in body fat so over-consumption may result in accumulation of toxic levels

1. Large folds, villi, have microvilli, brush-like appearance has large surface area to absorb nutrients

1. Humans store molecules in liver and muscle cells
2. Excess energy is stored in form of glycogen
3. Adipose fat cells also store energy

1. Food moves along in a single direction, tube can be organized into specialized compartments which carry out digestion and nutrient absorption in stepwise fashion
2. Animals can ingest food while earlier meals are still being digested

1. Ferments ingested material

1. Leads to anus and rectum
2. Reabsorbs water that enters alimentary canal

1. Fatty Acid
2. Amino Acid

1. Duodenum
2. Chyme from the stomach mixes with pancreatic, liver, and gallbladder juices
3. Hormones released by the stomach and duodenum control the digestive secretions into the alimentary canal

1. Fat globules turned into bile salts turned into fat droplets turned into pancreatic lipase turned into glycerol, fatty acids, and mono-glycerides

1. Creates bolus- easier to swallow
2. Tongue pushes bolus to back of oral cavity into pharynx
3. Distinguishes which food should be processed further (taste)

1. Proteins turned into pepsin turned into polypeptides turned into pancreatic enzymes turned into smaller polypeptides turned into pancreatic enzymes turned into amino acids

Vocabulary is a different note

1. Compartment with a single opening-pouch
2. Most hydrolysis happens internally and undigested materials remain in cavity, usually excreted the same opening by which food entered
3. Cannot eat more when food is still being digested

1. Chemical energy for cellular processes
2. Organic building blocks for carbohydrates and other macromolecules
3. Essential nutrients

1. Vegetation is more difficult to digest than meat
2. Longer digestive tract furnishes more time for digestion and more surface area for nutrient absorption

1. Breakdown of food compartments that are continuous with the outside of the animal's body
2. Allows animal to devour much larger sources of food than can be ingested by phagocytosis

1. Complete Digestion Tract/Alimentary Canal
2. Gastrovascular Cavity

1. Intercellular
2. Extracellular

1. Absorption
2. Digestion

1. Name the three nutritional needs that must be met by an animal?s diet.
2. Explain why megadoses of fat-soluble vitamins are more dangerous than equally large doses of water-soluble vitamins.
3. Compare intracellular and extracellular digestion
4. Distinguish between a complete digestive tract and a gastrovascular cavity. What advantage does a complete digestive tract afford over a gastrovascular cavity?
5. Name three functions of saliva and three functions of the tongue.
6. Compare the uptake of an amino acid and a fatty acid in the small intestine. Trace the path of each molecule following its uptake.
7. Explain how the small intestine is specialized for digestion and absorption.
8. Describe the major functions of the large intestine.
9. Describe the roles of symbiotic microorganisms in vertebrate digestion.
10. Explain where and in what form energy rich molecules may be stored in the human body.
11. Distinguish between alpha and beta cells in the pancreas and explain how their antagonistic hormones (insulin and glucagon) regulate carbohydrate metabolism.
12. Distinguish between type 1 and type 2 diabetes.