CHAPTER 41
ANIMAL NUTIRITON
Emily Moxie
THE NEED TO FEED

Three categories
Herbivores- eat only autotrphs (plants)
 Carnivores- eat only animals
 Omnivores- eat both autotrophs and animals


All animals will adapt to a change in diet if necessary
41.1 HOMEOSTASIS MECHANISMS MANAGE
AN ANIMAL’S ENERGY BUDGET

4 main feeding mechanisms;
Suspension feeders- sift small food particles from the
water
 Fluid feeders- live in or on their food source
 Bulk feeders- eat relatively large pieces of feed, uses
claws, fangs, jaws, and teeth to kill prey

ATP GENERATION

Nost ATP generation is based on the oxidation of
ebertu rich organic molecules
Carbohydrates
 Proteins
 Fats


Monomers of these can be used as fuel
GLUCOSE REGULATION AS AN EXAMPLE OF
HOMEOSTASIS

If the animal isn't growing or reproducing, there
tends to be surplus in energy department
In humans, the liver and muscles store energy ni the
form of glycogen
 Fuel may be taken out of storage depots and oxidized,
for weight loss

CALORIC IMBALANCE
Undernourishment- the diet of an animal is
chronically deficient in calories, body stores used
glycogen, and breaks down protein for fuel
 Overnourishment- the human body hoards fat in
the diet, so stores excess in molecules obtained
from food instead of using it for fuel.

OBESITY AS
A
HUMAN HEALTH PROBLEM
World Health Organization(WHO)- recognizes it
as a major global problem
 Percent of obese (very overseight) has doubled to
30%
 Obesity has many associated health problems

Diabetes
 Colon and breast cancer
 Cardiovascular complications, leading to heart
attacks and strokes
 Factored into 300,000 deaths a year

SOME USEFUL VOCABULARY
Leptin- suppresses appetite as its level increases,
and vice versa
 PYY- a hormone which is secreted in the small
intestine after meals, acts as an appetite
suppressant that counters the appetite stimulant
ghlerlin
 Gherlin-one of the signals that triggers hunger as
mealtimes approach

ANIMALS AND THEIR DIET
Excessive body fat may be beneficial for some
animals
 An animal’s diet must supply carbon skeletons
and essential nutrients
 animals need organic precursors (carbon
skeleton) from food
 Essential nutrients- musi be obtained
preasssembled because abimal’s cells cant make
them

ANIMALS AND THEIR DIET….CONTINUED
Malnourished- an anumal whose diet is missing
one or more essential nutirents
 Undernourished- caloric defiency
 An animal may be malnourished and
undernourished

ESSENTIAL AMINO ACIDS
Animals requie 20 amino acuds ot make proteins
(synthesize half)
 Essential amino acuds-obtained from food in
prefabricated form
 Insufficent of one or more amino acids is protein
deficient
 Kwoshiorkor-protein deficient but has enough
calories
 Amino rich foods- meat, eggs, cheese

ESSENTIAL FATTY ACIDS
Acids animals cannot produce, certain
unsaturated fatty acids (double bonds)
 Defieiencies with fatty acids are rare

VITAMINS
Vitamins are organic molecules requited in the
diet in amounts that are small compared to
quantities of essential amino acids and fatty
acids
 13 vitamins have been identified
 Recommended daily allowances(RDA)-nutrient
intakes proposed by nutritionalists to maintain
health

TYPES OF VITAMINS

Fat soluble


A,D,E,K they have many different functions
Water soluble

B-complex, coenzymes, metaboic process, vitamin Crequired for the production of connective tissue
MINERALS
Simple inorganic nutrients , usually required in
small amounts-from less than 1mg upto 2500mg
per day
 Mineral requirements vary from animal to
animal
 Most people have twenty times the amount of
salt than they need

THE MAIN STAGES OF FOOD PROCESSING AND
INGESTION, DIGESTION, ABSORPTION, AND
ELIMINATION
Ingestion- the act of eating, the fist stage of food
processing
 Digestion- the second stage of food processing, the
process of breaking food down into molecules small
enough for the body to absorb
 Enzymatic hydrolysis- the process of breaking bonds
with water in the splitting process

THE MAIN STAGES OF FOOD PROCESSING
CONTINUED

Absorption-after the food is digested, animal’s
cells take up small molecules (amino acids or
simple sugars) from the digestive compartment
the third stage of food processing
DIGESTIVE COMPARTMENTS

Animals reduce the risk of self digestion by
processing food in specialized compartments
INTRACELLULAR DIGESTION
Food vacuoles-cellular organelles where
nydrolyte enzymes work
 Intracellular digestion-deigestion within a cell,
mixes food with enzymes for safe digestion ina
protective membrane

EXTRACELLULAR DIGESTION

The breakdown of food outside cells
Occurs within compartments that are continuous
with the outside of the animal’s body
 Enables an animal to eat prey much larger that itself


Gastrovascular cavity- functions in both digestion
and distribution of nutrients throughout the body
EACH ORGAN OF THE MAMMALIAN DIGESTIVE
SYSTEM HAS SPECIALIZED FOOD-PROCESSING
FUNCTIONS
Peristalsis- rhythmic waves of contraction of the
canal, pushes the food along the tract
 Spincters- the ringlike alues, which closes off the
tube like drawstrings regulationf the passage of
material chambers of the canal
 Accessory glands of digestive system

Salivary glands
 Pancreas
 Liver
 gallbladder

THE ORAL CAVITY, PHARYNX AND
ESOPHAGUS
Oral cavity-triggers a nervous reflex that causes
the salivary glands to deliver saliva through
ducts to the oral cavity
 Salivary amlase- an enzyme that hydrolyzes
starch
 Bolus-the shape that the tongue makes cewed
food into
 Pharynx- a junction that opens to both the
esophagus and the windpipe (trachea)

THE ORAL CAVITY CONTINUED
Epiglottis- a cartilaginous flap which blocks the
blottis
 Esophagus- conducts food from the pharynx down
to the stomach by peristalsis

STOMACH
The stomach stores food and performs
preliminary steps of digestion, it has an
accordionlike folds, and an elastic wall
 Gastric juice- a digestive fluid secreted from the
stomach
 Pepsin- (in gastric juice)_ an enzyme that begins
hydrolysis of preteins, breaks down peptide
bands adjacent to specific amino acids, making
smaller polypeptides

STOMACH CONTINUED
Stomach’s second defense against self-deigestion
is mucus
 Acid chyme- a result of mixing and enzyme
actions, what begins in the stomach, becomes a
nutrient rich broth
 Pyloric sphincter- opening from the stomach to te
small intestine

THE SMALL INTESTINE
The small intestine is the longest section of the
alimentary canal
 Bile- a mix of substances that is stored in the
gallbladder until needed

EVOLUTIONARY ADAPTATIONS OF
VERTEBRATE’S DIGESTIVE SYSTEMS ARE OFTEN
ASSOCIATED WITH DIET

Dental adaptations


Stomach and intestinal adaptations



The type of teeth differ between carnivores, herbivores, and
omnivores
Carnivores have expandable stomachs
Herbivores and omnivores have long stomachs
Symbiotic adaptations

Elaborate adaptations in herbivores help them breakdown
cell walls