Biology 2 Second Test Animal Nutrition

Front 1

Needs as hetertrophs

Back 1

i. Reduced organic compounds (can’t make their own)
ii. Essential nutrients – those that must be supplied in the diet

Front 2

Heterotrophs essential nutrients

Back 2

1. Are not the same for all animals
2. Amino acids – 9 – 10 cannot be synthesized by humans
3. Fatty acids – it is hard, but not impossible, to become deficient in the two essential (to mammals) fatty acids, linoleate and linolenate
4. Vitamins – nutrients needed for metabolism; usually act as coenzymes
5. Minerals

Front 3

Modes of acquisition

Back 3

Absorbtion: in medium that has nutrients present you can absorb nutrients; example tapeworm.


Filter Feeding: opens mouth and filters it. Filters large volumes usually of a liquid.
Fluid feeders: sucking mouth parts acess fluid meal
Substrate feeder: consumes substrate.

Swallowers. : animals that don’t have the components to bite eat only things that fit in mouth.

Biters: can tear into pieces to eat.

Pre-digesters: prey digested outside body.

Symbioses: bacteria.

Front 4

Alimentary Canals

Back 4

deal with processing, digestion and secretion

Front 5

Alimentary canals (processes)

Back 5

Oral Cavity - mastication, start of digestion

Stomach - storage, mixing, acidification, more digestion

Small intestine - i. Near – duodenum, secretion of many enzymes, lots of digestion, secretion of bicarbonate to neutralize stomach acid
ii. Far – jejunum and ileum, responsible for more digestion, uptake of nutrients


LArge Intestine - water absorbtion

rectum - feces storage.

Front 6

Mouth

Back 6

Mechanical and chemical processing
Chewing reduces size
siliva digests carbohydrates

Front 7

esophogus

Back 7

transports food

Front 8

Stomach

Back 8

Mechanical and chemical processing
(digestion of proteins)

Front 9

Small intestine

Back 9

Chemical processing and absorption
(digestion of proteins, fats, carbohydrates;
absorption of nutrients and water)

Front 10

large intestine

Back 10

Water absorption and feces
formation

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Rectum

Back 11

holds feces

Front 12

anus

Back 12

eliminates feces

Front 13

Digestion

Back 13

Breaks down polymers and macromolecules into monomers
to basic building blocks nothing less then five monomers

ii. All forms of life (that is, all kinds of food) share the same chemical structures, and therefore the same monomers

Each biologic polymer has a hydrolytic enzyme to break it down

Front 14

Carbohydrate digestion types

Back 14

polymers are starches, glycogen, and cellulose (and chitin). No animal can digest cellulose (without help)

Front 15

Carbohydrate digestion process

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ii. Salivary amylase starts to digest polysaccharides in mouth, continues in stomach

iii. Pancreatic amylase (more than salivary) continues to digest polysaccharides down to the disaccharide level. Secreted into small intestine

iv. Disaccharidases digest specific disaccharides into simple sugars

Front 16

Disaccharidases

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bound to S.I. endothelium (brush border)

2. Maltase for maltose, Sucrase for sucrose, Lactase for lactose, etc.

Front 17

Protein Digestion

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i. Proteins are polymers built up of 20 different amino acids
ii. Proteases are responsible for digestion. Can be specific or non-specific

Front 18

Protein Digestion Process step 1

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Starts in stomach Pepsin is secreated by chief cells, inactive form is pepsinogen

is a specific protease only cleaves to certain amino acids

Acidity plus pre-existing pepsin converts inactive to active form

Front 19

Protein digestion process step 2

Back 19

iv. Acidity in stomach due to secretion of gastric juice (containing hydrochloric acid) by parietal cells lowers pH to 2.
1. Kills bacteria
2. Denatures proteins, allowing easier access for hydrolytic enzymes and breakdown of ECM
3. Stomach wall protected by mucus coat, rapid turnover of cells

Front 20

Protein digestion process step 3

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v. After a few hours in the stomach, “acid chyme” is released by the pyloric sphincter, a small amount at a time, into duodenum.

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Protein digestion process step 4

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vi. Proteases secreted into small intestine (S.I.)

Front 22

Enzymes in small intestin

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1. Trypsin (from trypsinogen) specific protease, secreted by pancreas
2. Chymotrypsin (from chymotrypsinogen) specific protease, secreted by pancreas
3. Carboxypeptidase (from procarboxypeptidase), non-specific (attacks C-terminal), secreted by pancreas.
4. Aminopeptidase, non-specific (attacks N-terminal), secreted by S.I. epithelium.
5. Enteropeptidase – secreted by S.I. epithelium; activates trypsin, which activates others.
6. Dipeptidases – bound to epithelium, split dipeptides into single amino acids

Front 23

Fat Digestion

Back 23

i. Fats are not polymers – three fatty acids attached to glycerol via ester bonds.
ii. Digested by lipase (from pancreas), secreted into S.I.
iii. Fat needs to be emulsified for hydrolysis to occur
1. Bile salts are detergents that break up fat globules
2. Bile salts are produced in the liver and stored in the gallbladder

Front 24

Nucleic acid digestion

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in lumen of small intestine i. Nucleases (from pancreas) break down DNA, RNA

ii. Nucleotidases: nucleotide to nucleoside and phosphate
iii. Nucleosidases: nucleoside to bases and sugars

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Anatomy of Intestinal lining

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ii. Each villus contains capillaries, lacteal (lymph vessel), covered with carbohydrate-rich glycocalyx filaments
iii. Coated with bound digestive enzymes that produce monomers near point of uptake

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Absorbtion of nutrients in S.I.

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i. Simple diffusion -- fatty acids, monoglycerides through membrane, some sugars and alcohols through pores
ii. Carrier-mediated transport – hydrophilic, large molecules like amino acids and larger sugars
iii. Active transport – amino acids, glucose

Front 27

Lipid uptake

Back 27

i. After diffusion, fats are recreated in the epithelium from monoglycerides and fatty acids. These are packaged with cholesterol and coated with protein to form chylomicrons.
ii. Chylomicrons are transported by exocytosis from epithelium to lacteal, and enter the bloodstream from the lymphatic system

Front 28

uptake of nutrients in the blood

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i. Other than fats, nutrients mainly enter the blood in the capillaries of the villus
ii. These capillaries rejoin to form the hepatic portal vein, which empties into the liver.
iii. The liver modifies the composition of the blood, storing excess sugars and amino acids

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Reabsorption of water

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a. Large intestine reabsorbs water and inorganic ions from the lumen
b. Adds mucus to help form feces
c. Symbiotic bacteria in the L.I. form necessary vitamins (especially K), in many animals help in digestion through fermentation

Front 30

Hormonal control

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A complex mixture of possitive and negative feedback controls include:

b. Gastrin

Secretin

d. Cholecystokinin

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Gastrin

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is secreted by the stomach into the blood stream, in response to the presence of food, induces further secretion of HCl

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secretin

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is secreted by the duodenum, targets pancreas (release bicarb) and stomach (lower motility) in response to food

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cholecystokinin

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secreted by the duodenum in response to fatty acids or amino acids, targets pancreas and gallbladder

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Gastric inhibitory peptide

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in response to high levels of fatty acids, inhibits gastric activity

Front 35

Cellullous digestion

Back 35

can be digested by Rumimants.
which include cattle, shep, deer, giraffs

Front 36

Rummamint stomach structure

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i. Rumen – site of fermentation; rumination
ii. Rumen + reticulum = first division
iii.Omasum + abomasum = second division.
Abomasum is true stomach with digestive enzymes.