CHAPTER 41ANIMAL NUTIRITONEmily 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 C-required 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 The type of teeth differ between carnivores,

herbivores, and omnivores Stomach and intestinal adaptations

Carnivores have expandable stomachs Herbivores and omnivores have long stomachs

Symbiotic adaptations Elaborate adaptations in herbivores help them

breakdown cell walls