Chapter 41:

Chapter 41:Animal Nutrition

Katie Dulak and Jared PeytonA.P Biology 5th periodV. Vilardi1All animals eat other organisms!3 Types of Heterotrophs (organisms that dont create their own food)

Herbivores (consume autotrophs)CowsCarnivores (consume other heterotrophs)LionsOmnivores (Consume both autotrophs and heterotrophs)People

This exemplifies what animals USUALLY eat. All Animals are opportunistic, meaning theyll eat what they can get. (ie: cows will eat worms along with their grass)

2See this lion?When it consumes this zebra in its entirety, it will also be consuming the organic plant material in its stomach.

3Animals have 3 basic nutritional needs for their diets:Fuel (chemical energy) Organic raw materials (biosynthesis)Essential nutrients, like vitamins and minerals, that the body cannot make on its own.

4The 4 main feeding mechanisms of animals:

5Check for understandingWhat kind of feeder are you?

Can you think of another substrate feeder?

What are leeches considered?6Staying within budgetAnimals come naturally equipped with certain mechanisms that control how much energy an animal spends and where its spent.

The highest source of income for that budget is the production of ATP, which comes the metabolism of ingested foods via cellular respiration.

These foods provide, in descending order, the energy needed to make the body work: Fats, Carbohydrates, and Proteins.7Redistribution of CaloriesWhen an excess of calories is consumed, the extras can go towards biosynthesis (ever hear the growing boys adage?)If the animal is done growing, the calories are stored in depots (like the spare tire).The liver and muscles store energy as glycogen, a major fuel source for cells, and the metabolism of such is a great example of homeostasis!8Glucose Regulation

9Breaking into the surplusWhen less calories are consumed than burned, the body dips into the depots for energy. (Exercise, starvation)

Order of energy consumption (oxidation):Liver Glycogen->Muscle Glycogen/Fat

The average person can live off of .3 kilograms of fat per day (several weeks of starvation before the energy sources run dry.10A budget out of balanceUndernourishment the body runs out of fat and glycogen to run off of, so it begins breaking down its own proteins. Muscles decrease, and the brain becomes protein deficient.

This can be caused by starvation (seen in war stricken or impoverished nations, and places that suffer from drought).

It can also be caused by anorexia nervosa.The detrimental effects, even if they dont cause death of the organism, can be irreversible11Overnourishment (obesity) is the problem more common in the United States. When extreme excesses of the body stores it in the form of fat.In the case of carbohydrates, excesses increase rate of oxidation.

Fat cell12The obesity issue

13Obesity is proven to be a factor in diabetes, colon and breast cancer, and pulmonary (heart) problems.The body has homeostatic mechanisms designed specifically to regulate body weight.Among these mechanisms are hormones, which are excreted by different organs and tissues of the body, that control hunger.These hormones travel through the bloodstream to the brain to flip the switch between on and off in the satiety center14Stimulants: Ghrelin

Suppressants: PYY, Leptin, Insulin15One wrong chromosomeResearchers found that in some individuals, genetic mutations that causes abnormal leptin (from fat) production impact weight regulation greatly.

Which mouses genes are a little too tight?*Hint: its the fat one.Why? He is suffering from a genetic mutation in which his body doesnt produce enough leptin to maintain his hunger levels to keep that beach body.16Time for confusionThose deemed obese have very high levels of Leptin in their body.

Leptin comes from fat, so it makes sense that people with excess fat have excess leptin, even though its supposed to be an appetite suppresant.

Heres the deal: just like the case SHOULD be with people eating, the brain only accepts certain concentrations of Leptin before it just refuses.

*Someone hands you a piece of cake and you eat happily. Someone tries to force-feed you the entire cake, you shut your mouth and become extremely displeased.17The extremes

18Why is it that everything delicious is terrible for you?Hamburgers and Pizza: Foods we love that are bad for you. Why must this be so?At one point in time it might have been beneficial to stock up in foods high in fat. Back in the days when our ancestors ran around in loincloths and lived in caves, they were hunters and gatherers with limited access to high-fat foods. So when they were available, it was necessary for the body to store the fat so there was something to sustain them during the times when the only accessible foods were berries and nuts.Following Darwins Survival of the Fittest theory, those who had the capacity to store more fat had a higher chance of surviving, since they had that to live off of during times of famine.Today, however, the only hunting and gathering people do is in the grocery store19The difference between man and beastFor some animals, storing fat and becoming, by our standards, obese, can be beneficial. Animals that go through hibernation during the winter survive on their fat storages when food is scarce and the conditions do not favor locating food sources.Also, animals that bring food to their young need this privilege. Storing the energy as fat helps the young to survive when food is scarce, and it helps the parents by not requiring them to carry as much.

20Check for understandingWhat does your body use to control hunger?No having enough fat/glycogen leads to a condition called?And the opposite of that, having WAY too much is?What can obesity lead to?

21Carbon Skeletons and essential nutrientsBiosynthesis: Formation of a chemical compound by a living organism

The raw materials of biosynthesis come from organisms diets.

An organism takes these materials, called carbon skeletons, and uses them to create the complex molecules needed for growth.

Carbohydrates, proteins, and lipids are formed from the combination of organic carbons (like sugar) and a source of nitrogen (usually amino acids derived from the digestion of proteins).

22Essential nutrients: substances obtained from the diet that the body cant make on its own thats necessary for health and development.Some that are essential for certain animals arent for others.Human beings have to obtain their vitamin C from their body, while goats make it on their own.An animal lacking an essential nutrient is said to be malnourished.

23The fantastic fourThere are four classifications of essential nutrients:Essential amino acidsEssential fatty acidsVitaminsMinerals

24Amino AcidsAnimals require 20 amino acids to synthesize proteins, but only make about half on their own. There are 8 essential amino acids for human beings, and the same is the case for most animals.These are obtained through the diet.A diet proividing an insufficient amount of any of these 8 amino acids leads to a form of malnutrition called protein deficiency.The side effects of which include mental and physical retardation.

Effects of protein deficiency!

25Kwashiorkor

Due to protein deficiency, this little boys blood lacks the capacity to absorb water from the body properly.

26Where to get itThe best sources of essential amino acids are meats, eggs, and cheese.Animal proteins contain the perfect balance of pretty much all of the essential amino acids.Plants individually have some amino acids, so the best way to make sure to get a sufficient amount of each is to figure out which plan has each amino acid, and arrange the diet accordingly

27Meeting high demandsSome animals have adaptations that help them in times of great need.Penguins, for instance, use muscle protein as amino acids to replace the proteins used during molting.

28Fatty acidsAnimals can produce MOST of the fatty acids they need, but not ALL.(Those with double bonds)Linoleic acid, for instance, is required for the production of some of the bodys phospholipids found in membranes, and is obtained through the diet.Human and animal diets are usually overstocked in essential fatty acids, so deficiencies are rare.

29VitaminsCompared to essential amino and fatty acids, the required amount of vitamins for the body is fairly small.These, however, follow by the rule of speak softly but carry a big stickVitamin deficiencies can cause HUGE problems.13 Essential vitamins have been identified and categorized as either water-soluble or fat-soluble.An overdose in water-soluble vitamins is generally harmless, but overdosing in fat-soluble vitamins can lead to a build-up of toxic proportions.30

31MineralsMinerals are inorganic materials needed in the animal diet.Like vitamins, small amounts are needed, with exceptions like calcium* and phosphorous** (for bone development).*also necessary for the normal functioning of nerves and muscles,**also an ingredient of ATP and nucleic acids.

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33Warning!: Consuming minerals in excess can be potentially harmful!The average human being consumes over 20 times the amount of salt required by the human body.This much salt can upset the homeostatic balance and lead to bad side effects, like high blood pressure.Iron too can be harmful, causing liver damage when overdosed on.34Check for understanding:What are the 4 classifications of essential nutrients?What is caused by insufficient amounts of essential amino acids?What is the creation of internal chemical compounds from raw organic material called?

35Food Processing: 4 easy stepsIngestion: put food in your mouth. Chew it. Swallow it. You have ingested food.

36Digestion:In digestion, hydrolytic enzymes break down the food molecules small enough to be absorbed by the body.The material in the foods are sorted out and shipped to their appropriate division:Polysaccharides and disaccharides are split into simple sugars, fats are digested to glycerol and fatty acidsproteins are split into amino acidsnucleic acids are cleaved into nucleotides37Absorption and ExcretionDuring absorption the materials sorted from digestion are sent to where they need to go.It is during this stage that the body receives its daily dose of vitamin C (and all the other essential vitamins, minerals, and acids) Excretion is the process by which the body eliminates the leftovers and waste through the digestive compartment. 38

Important Vocabulary:Peristalsis: contraction and relaxation of muscles that push food through the digestion process.Pepsinogen: Inactive enzyme Hydrochloric acid: Gastric juicePepsin: Active enzyme created by the combination of pepsinogen and hydrochloric acid39If we eat organic materialsand the digestion process is primarily involuntaryhow do we not eat ourselves?Digestive compartments is the answer to that.These specialized compartments safely house the food processing and ship the end result to where it needs to go.40Intracellular digestionFood vacuoles engulf food materials through either phagocytosis or pinocytosis, and fuse with lysosomes to break it down without digesting the cells own cytoplasm.This is the sponges only form of digestion, which is unusual in the animal kingdom.

41Extracellular digestionDigestion that occurs outside of the cells, which occurs in he gastrovascular cavity. This functions in breaking down foods AND distributing the materials throughout the body (hence the vascular part).

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Hydra digestion:Hydras sting their prey with nematocysts.Then they stuff the victim straight into their gastrovascular cavity.Specialized gland cells of the gastrodermis, the tissue layer that lines the cavity, then secrete digestive enzymes that break the soft tissues of the prey into tiny pieces. Other gastrodermal cells, called nutritive muscular cells, engulf these food particles.After a hydra has digested its meal, undigested materials remaining in the gastrovascular cavity are eliminated through the single opening, which functions as both mouth and anus.

43Different digestion for different critters

44The Digestive SystemDigestive systems in most mammals are very similar.Most have a digestive tube that extends from the mouth to the anus. This tube is called a complete digestive tract or an alimentary canal. 45Movement of food in the canalPeristalsis is the contractions of smooth muscles in the canal to move foodRing-like valves called sphincters act like a draw string to enable this function.

46Glands in the digestive systemSalivary Glands- secrete saliva into the oral cavity and help with swallowing food and other functionsPancreasLiver- produces bile and stores it in the gallbladderGallbladder- stores digestive juices47How we eat foodWhen food enters the mouth, or oral cavity, salivary glands secrete saliva into the oral cavity Saliva helps protect the mouth from abrasions and makes food easier to swallow. Saliva also neutralizes acid, and kills many of the bacteria that is in the food.Actual digestion of carbohydrates begins in the oral cavity by the saliva

48The tongueThe tongue plays a major role in eating foodIt manipulates the food to chew it and helps you to swallow by pushing the food into the back of your throat into the pharynx

49PharynxThe Pharynx is space between the oral cavity and esophagusIt opens to the esophagus and windpipeThe epiglottis is a flap that prevents food from going into the windpipe

50Then.Then the food goes down the esophagus by a process called peristalsisThe esophagus leads the food all the way down to where it spills into the stomachThe act of swallowing is voluntary, but peristalsis is involuntary51The StomachThe stomach holds the food and performs steps in digestion.The stomach is made of very elastic folds of tissueThe stomach secretes gastric juice which is a digestive fluid for the food.This digestive fluid breaks down the food and kills most bacteria52Continued..Also in gastric juice is an enzyme called pepsin.Pepsin hydrolyzes protein in the foodPepsinogen prevents Pepsin from destroying the cells of the stomach

53ContinuedThe opening from the stomach to the small intestine is called the pyloric sphincter

54The Small IntestineMost of the enzymatic digestion of food and nutrient absorption happens in the small intestineBile from the gallbladder is used in digestion in the small intestineA sphincter regulates the movement of material from the small intestine to the large intestine at a T-shaped junction55The Large IntestineThe large intestine is also called the colon. Waste products of digestion called feces move along the colon and end up in the rectumThe rectum stores the feces There are two sphincters between the rectum and anusContractions of the colon creates the urge to go to the bathroom and via relaxation of the anal sphincter, the feces exit the body56

57Check for UnderstandingWhat is the involuntary muscle action that moves food throughout the digestive system?What is the first substance added to food to begin the breakdown?

58We must adapt!Animals have many adaptations to their body that are there because of their diet.Lions have big ferocious fangs, birds have beaks, people have a combination of incisors and molars, all of which are used by each animal to eat what their diet consists of.59Dental AdaptationsDental adaptations are the shape of teeth that help animals eat their foodFor example carnivores have more sharp teeth to bite into meat while herbivores have duller teeth to mash plant food 60

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62Intestinal AdaptationsAdaptations arent just in the teeth.For example African lions can consume very large amounts of food because they dont eat very often, like the hunter gatherer thing with people back in the day, its survival of the fittest.63

64Symbiotic adaptationsCreatures that dont get all of their essential nutrients from animals like people and carnivores do have special adaptations to compensate for this.One issue? Plants consumed by herbivores store their energy in the cellulose of cell walls, and animals dont have the enzymes that can break this down.However, these animals have symbiotic microbes in their system that DO break them down, microbes that carnivores dont have.65The most impressive adaptation: ruminants

66Check for UnderstandingName another adaptation of an animal that is based around the diet?What do herbivores use to make up for the fact that they themselves cant break down the energy source in plants?

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