Chapter 41: Animal Nutrition

1
Chapter 41 Animal Nutrition

• Why do we eat?
• Fuel (chemical energy)
• To get organic material for biosynthesis (carbon
  skeletons)
• Essential nutrients (substances that cant be
  made from scratch)
• What are the 4 main feeding mechanisms of
  animals?
• Suspension feeders
• Substrate feeder
• Fluid feeders
• Bulk feeders

2
Figure 41.2 Four Main Feeding Mechanisms of
Animals
SUSPENSION FEEDERS
SUBSTRATE FEEDERS
Feces
Baleen
Caterpillar
FLUID FEEDERS
BULK FEEDERS
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Chapter 41 Animal Nutrition

• Why do we eat?
• What are the 4 main feeding mechanisms of
  feeding?
• When our bodies need energy, what is the order of
  fuel usage?
• (fat- protein-
  carbs- )
• How is appetite regulated in the body?
• Hormones
• source fcn
• PYY S. intestine suppresses appetite
• (after meals)
• Insulin pancreas suppresses appetite ?blood
  sugar?insulin
• Ghrelin stomach triggers hunger ?weight
  ?ghrelin
• () makes dieting difficult
• Leptin adipose suppresses appetite
• ? Fat ? leptin ? appetite
• ? Fat ? leptin ? appetite

1st
2nd
3rd
4
Figure 41.5 A few of the appetite-regulating
hormones
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Chapter 41 Animal Nutrition

• Why do we eat?
• What are the 4 main feeding mechanisms of
  feeding?
• When our bodies need energy, what is the order of
  fuel usage?
• (fat- protein-
  carbs- )
• How is appetite regulated in the body?
• Hormones
• source fcn
• PYY S. intestine suppresses appetite
• (after meals)
• Insulin pancreas suppresses appetite ?blood
  sugar?insulin
• Ghrelin stomach triggers hunger ?weight
  ?ghrelin
• makes dieting difficult
• Leptin adipose suppresses appetite
• ? Fat ? leptin ? appetite
• ? Fat ? leptin ? appetite
• What happens if there is a mutation in the leptin
  system?

1st
2nd
3rd
6
Figure 41.6 A ravenous rodent
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Chapter 41 Animal Nutrition

• Why do we eat?
• What are the 4 main feeding mechanisms of
  feeding?
• When our bodies need energy, what is the order of
  fuel usage?
• How is appetite regulated in the body?
• What happens if there is a mutation in the leptin
  system?
• What are essential nutrients what are the 4
  classes?
• Nutrients our bodies cannot make
• Essential amino acids (8)
• Essential fatty acids certain unsaturated FAs
  linoleic acid
• Vitamins
• Minerals

8
Figure 41.10 Essential amino acids from a
vegetarian diet
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Table 41.1 Vitamin Requirements of Humans
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Table 41.2 Mineral Requirements of Humans
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Chapter 41 Animal Nutrition

• Why do we eat?
• What are the 4 main feeding mechanisms of
  feeding?
• When our bodies need energy, what is the order of
  fuel usage?
• How is appetite regulated in the body?
• What happens if there is a mutation in the leptin
  system?
• What are essential nutrients what are the 4
  classes?
• Nutrients our bodies cannot make
• Essential amino acids (8)
• Essential fatty acids certain unsaturated FAs
  linoleic acid
• Vitamins
• Minerals
• What is the difference between malnourished
  undernourished?
• Under get all essentialsjust not enough
• Mal missing some essentials
• 8. How is food processed?

12
Figure 41.12 The four stages of food processing
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Chapter 41 Animal Nutrition

• Why do we eat?
• What are the 4 main feeding mechanisms of
  feeding?
• When our bodies need energy, what is the order of
  fuel usage?
• How is appetite regulated in the body?
• What happens if there is a mutation in the leptin
  system?
• What are essential nutrient what are the 4
  classes?
• What is the difference between malnourished
  undernourished?
• How is food processed?
• What is the path that food takes through us?
• Mouth?esophagus?stomach?small intestine?large
  intestine?rectum?toilet

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Figure 41.15 The human digestive system
Parotid gland
Sublingual gland
Submandibular gland
Stomach
Rectum
A schematic diagram of the human digestive system
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Chapter 41 Animal Nutrition

• Why do we eat?
• What are the 4 main feeding mechanisms of
  feeding?
• When our bodies need energy, what is the order of
  fuel usage?
• How is appetite regulated in the body?
• What happens if there is a mutation in the leptin
  system?
• What are essential nutrient what are the 4
  classes?
• What is the difference between malnourished
  undernourished?
• How is food processed?
• What is the path that food takes through us?
• Mouth?esophagus?stomach?small intestine?large
  intestine?rectum?toilet
• 10. Lets find out what happens along the way?

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Figure 41.16 From mouth to stomach the
swallowing reflex and esophageal peristalsis
(layer 1)
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Figure 41.16 From mouth to stomach the
swallowing reflex and esophageal peristalsis
(layer 2)
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Figure 41.16 From mouth to stomach the
swallowing reflex and esophageal peristalsis
(layer 3)
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Figure 41.21 Flowchart of enzymatic digestion in
the human digestive system
Carbohydrate digestion
Protein digestion
Nucleic acid digestion
Fat digestion
Oral cavity, pharynx, esophagus
Polysaccharides (starch, glycogen)
Disaccharides (sucrose, lactose)
Salivary amylase
Smaller polysaccharides, maltose
Stomach
Proteins
Pepsin
Small polypeptides
Lumen of small intes- tine
Fat globules (Insoluble in water, fats aggregate
as globules.)
Polypeptides
Polysaccharides
DNA, RNA
Pancreatic amylases
Pancreatic trypsin and chymotrypsin (These
proteases cleave bonds adjacent to certain amino
acids.)
Pancreatic nucleases
Bile salts
Maltose and other disaccharides
Fat droplets (A coating of bile salts prevents
small drop- lets from coalescing into larger
globules, increasing exposure to lipase.)
Nucleotides
Smaller polypeptides
Pancreatic carboxypeptidase
Pancreatic lipase
Amino acids
Glycerol, fatty acids, glycerides
Epithelium of small intestine (brush border)
Small peptides
Nucleotidases
Nucleosides
Dipeptidases, carboxypeptidase, and
aminopeptidase (These proteases split off one
amino acid at a time, working from opposite ends
of a polypeptide.)
Disaccharidases
Nucleosidases and phosphatases
Monosaccharides
Nitrogenous bases, sugars, phosphates
Amino acids
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Figure 41.17 The stomach and its secretions

• stomach epithelium secretes gastric juice
• parietal cells secrete HCl chief cells secrete
  pepsinogen
• pH 2

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Figure 41.19 The duodenum
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Figure 41.21 Flowchart of enzymatic digestion in
the human digestive system
Carbohydrate digestion
Protein digestion
Nucleic acid digestion
Fat digestion
Oral cavity, pharynx, esophagus
Polysaccharides (starch, glycogen)
Disaccharides (sucrose, lactose)
Salivary amylase
Smaller polysaccharides, maltose
Stomach
Proteins
Pepsin
Small polypeptides
Lumen of small intes- tine
Fat globules (Insoluble in water, fats aggregate
as globules.)
Polypeptides
Polysaccharides
DNA, RNA
Pancreatic amylases
Pancreatic trypsin and chymotrypsin (These
proteases cleave bonds adjacent to certain amino
acids.)
Pancreatic nucleases
Bile salts
Maltose and other disaccharides
Fat droplets (A coating of bile salts prevents
small drop- lets from coalescing into larger
globules, increasing exposure to lipase.)
Nucleotides
Smaller polypeptides
Pancreatic carboxypeptidase
Pancreatic lipase
Amino acids
Glycerol, fatty acids, glycerides
Epithelium of small intestine (brush border)
Small peptides
Nucleotidases
Nucleosides
Dipeptidases, carboxypeptidase, and
aminopeptidase (These proteases split off one
amino acid at a time, working from opposite ends
of a polypeptide.)
Disaccharidases
Nucleosidases and phosphatases
Monosaccharides
Nitrogenous bases, sugars, phosphates
Amino acids
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Figure 41.20 Protease activation
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Chapter 41 Animal Nutrition

• Why do we eat?
• What are the 4 main feeding mechanisms of
  feeding?
• When our bodies need energy, what is the order of
  fuel usage?
• How is appetite regulated in the body?
• What happens if there is a mutation in the leptin
  system?
• What are essential nutrient what are the 4
  classes?
• What is the difference between malnourished
  undernourished?
• How is food processed?
• What is the path that food takes through us?
• Lets find out what happens along the way?
• What hormones control digestion?
• CCK cholecystokinin
• Secretin
• Gastrin
• Enterogastrone

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Figure 41.22 Hormonal control of digestion
This ensures enzymes are only present when needed.
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Chapter 41 Animal Nutrition

• Why do we eat?
• What are the 4 main feeding mechanisms of
  feeding?
• When our bodies need energy, what is the order of
  fuel usage?
• How is appetite regulated in the body?
• What happens if there is a mutation in the leptin
  system?
• What are essential nutrient what are the 4
  classes?
• What is the difference between malnourished
  undernourished?
• How is food processed?
• What is the path that food takes through us?
• Lets find out what happens along the way?
• What hormones control digestion?
• How where are nutrients absorbed?
• Facilitated diffusion active transport of
  monomers
• Microvilli of small intestine

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Figure 41.23 The structure of the small intestine
Microvilli(brush border)
Vein carrying blood to hepatic portal vessel
Bloodcapillaries
Epithelialcells
Epithelial cells
Largecircularfolds
Lacteal
Villi
Key
Lymph vessel
Villi
Nutrientabsorption
Intestinal wall
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Chapter 41 Animal Nutrition

• Why do we eat?
• What are the 4 main feeding mechanisms of
  feeding?
• When our bodies need energy, what is the order of
  fuel usage?
• How is appetite regulated in the body?
• What happens if there is a mutation in the leptin
  system?
• What are essential nutrient what are the 4
  classes?
• What is the difference between malnourished
  undernourished?
• How is food processed?
• What is the path that food takes through us?
• Lets find out what happens along the way?
• What hormones control digestion?
• How where are nutrients absorbed?
• How where are fats absorbed?
• Fats are emulsified by bile salts
• Absorbed into the lacteal w/in the villi lymph
  system

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Figure 41.24 Digestion and absorption of fats
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Chapter 41 Animal Nutrition

• Why do we eat?
• What are the 4 main feeding mechanisms of
  feeding?
• When our bodies need energy, what is the order of
  fuel usage?
• How is appetite regulated in the body?
• What happens if there is a mutation in the leptin
  system?
• What are essential nutrient what are the 4
  classes?
• What is the difference between malnourished
  undernourished?
• How is food processed?
• What is the path that food takes through us?
• Lets find out what happens along the way?
• What hormones control digestion?
• How where are nutrients absorbed?
• How where are fats absorbed?
• Fats are emulsified by bile salts
• Absorbed into the lacteal w/in the villi lymph
  system
• 14. What is the purpose of the large intestine?
• Absorption of water makes feces solid
• Home of endosymbiotic bacteria

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Chapter 41 Animal Nutrition

• Why do we eat?
• What are the 4 main feeding mechanisms of
  feeding?
• When our bodies need energy, what is the order of
  fuel usage?
• How is appetite regulated in the body?
• What happens if there is a mutation in the leptin
  system?
• What are essential nutrient what are the 4
  classes?
• What is the difference between malnourished
  undernourished?
• How is food processed?
• What is the path that food takes through us?
• Lets find out what happens along the way?
• What hormones control digestion?
• How where are nutrients absorbed?
• How where are fats absorbed?
• What is the purpose of the large intestine?
• What are some evolutionary adaptations of the
  vertebrate digestive system?
• Teeth shape
• Intestinal length
• Symbiotic adaptations for fermentation in
  herbivores
• Storage chambers

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Figure 41.26 Dentition and diet
Incisors
Canines
Molars
(a) Carnivore
Premolars
(b) Herbivore
(c) Omnivore
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Figure 41.27 The digestive tracts of a carnivore
(coyote) and herbivore (koala) compared
Carnivore
Herbivore
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Figure 41.28 Ruminant digestion
Reticulum. Some boluses also enter the
reticulum. In both the rumen and the reticulum,
symbiotic prokaryotes and protists (mainly
ciliates) go to work on the cellulose-rich
meal. As by-products of their metabolism, the
microorganisms secrete fatty acids. The cow
periodically regurgitates and rechews the cud
(red arrows), which further breaks down
the fibers, making them more accessible to
further microbial action.
Omasum. The cow then reswallows the cud
(blue arrows), which moves to the omasum, where
water is removed.