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41 Cards in this Set
- Front
- Back
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What are the four processes needed to obtain energy from food?
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Four processes needed to obtain energy from food:Ingestion, digestion, absorption, and elimination
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What are the two basic requirements for animal life?
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1. chemical energy synthesize ATP 2. Carbon-containing molecules |
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Heterotrophs |
animals are * obtain energy and nutrients from other organisms rather than making their own food |
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Nutrients |
animals get chemical energy & carbon-containing building blocks from nutrients (e.g. carbs, proteins, fats) *fats provide most energy *compared to 4cal/g for proteins & carbs *food is any material that contains nutrients |
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Essential nutrients basic definition |
substances an organism needs to remain alive are known as essential nutrients: -cannot synthesize -e.g. amino acids, fatty acids, vitamins, minerals |
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Essential nutrients break down: |
of 20 amino acids, 11 can be made * 9 essential amino acids cannot be synthesized by humans; must be obtained by food; anything that provides energy Fatty acids: can synthesize all but two (found in plants, fish) Vitamins: organic, c-compounds vital for health; required only in minute; vitamins function as coenzymes Minerals (include Electrolytes) *imp components of cofactors or structural materials (e.g. Ca, Fe, Mg, Na, K, CI) *osmotic balance, memebrane function |
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Know how to calculate calories and which macromolecules provide the most energy |
First determine how many of the calories in the food will come from carbohydrates. In general, carbs contain 4 calories for every gram, so multiply the number of carbs listed on the label by 4
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Amino acids |
of 20 amino acids, 11 can be made* 9 essential amino acids cannot be synthesized by humans; must be obtained by food; anything that provides energy an essential nutrient; substances an organism needs to remain alive. *Amino acids are the building blocks of proteins. Proteins, in turn, are necessary for many of the structures and functions in our bodies.Our bodies require 20 different amino acids to accomplish all they need to do for us to live. Together, these amino acids are sequenced and folded to combine in almost endless ways. The resulting proteins are used to build our muscles, bones, hair, and nails, but that is only the beginning. |
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Vitamins |
organic, c-compounds vital for health; required only in minute; function as coenzymes *any of a group of organic compounds that are essential for normal growth and nutrition and are required in small quantities in the diet because they cannot be synthesized by the body. |
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Minerals |
(include Electrolytes)*imp components of cofactors or structural materials (e.g. Ca, Fe, Mg, Na, K, CI)*osmotic balance, membrane function *a chemical element required as an essential nutrient by organisms, other than carbon, hydrogen, nitrogen, oxygen and sulfur present in common organic molecules. *salts |
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Electrolytes |
Included with minerals *Common human electrolytes are sodium chloride, potassium, calcium, and sodium bicarbonate. Electrolytes control the fluid balance of the body and are important in muscle contraction, energy generation, and almost every major biochemical reaction in the body |
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what are the 4 main mouthpart structures in organisms? |
*NS has tightly matched structure of animal mouthparts to feeding methods *evolution is not progressive; animal mouthparts do not get "better" over time in the sense of being more complex 4 Main mouthparts; Incisors, canines, premolars, molars Carnivore: lg. canines, reduced molars Herbivores: Large and many molars Omnivore's:combo of all |
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what kind of feeders are there?
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1.Carnivore 2.Omnivore 3.Herbivore |
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what is the importance of the pharyngeal jaw in cichlids?
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fish that inhabit the Rift lakes of East Africa - Lake Victoria is home to 300 endemic (only found there) cichlids. - most feed on a specific item, but as a group they exploit almost every conceivable food source in the lake -they can exploit so many food sources because they have a set of Pharyngeal Jaws *cichlids use them to bite and they have a set of specialized tooth structures that are adapted to the type of food |
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Pharyngeal Jaws |
located behind the normal oral jaws and upper pharyngeal jaw attaches to skullI
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Ingestion:
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bring food into digestive tract
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Digestion: |
breakdown of food into small enough pieces to allow for absorption (nutrient uptake) - occurs in tube-like structure (gastrointestinal tract) - absorption takes place through cell membranes of GI tract - Along GI tract are glands, secrete enzymes that break down food into small molecules to be absorbed |
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Where does digestion take place?
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Digestive tract - it has two general designs: 1. Incomplete digestive tracts 2. complete digestive tracts |
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Incomplete Digestive tracts |
-one opening for both food and waste elimination -digestion takes place in a Gastro vascular Cavity *in more simplistic organisms
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Complete Digestive Tracts:
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-two openings, mouth for ingestion and anus for waste elimination - in addition, several accessory organs contribute to digestion |
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Digestive tracts: 7
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1.mouth: site of mechanical and chemical processing. tongue manipulates food so that teeth can chew food; saliva digests carbo's 2. Esophagus: Transports food 3. Stomach: site of mechanical processing (digests proteins) 4. Small intestine: site of chemical processing and absorption (digests proteins, fats, carbs; absorbs nutrients and water) 5. Lg. intestine: absorbs water and forms feces; contains symbiotic bacteria 6. Appendix: contains immune tissues: harbors symbiotic bacteria 7. Anus: eliminates feces |
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Accessory organs: 4
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1.salivitory glands: secretes enzymes that digest carbo's; supply lubricating mucus 2. Liver: secretes molecules that aid in fat digestion 3. Gallbladder: stores secretions from liver; empties into small intestine 4. pancreas: secretes enzymes and other materials into small intestine |
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what are the advantages of the complete digestive tract? Three |
1. animals can feed on large pieces of food 2. chemical and physical processes can be separated within the GI tract, so that they occur independently of each other and in a prescribed sequence 3. material can be ingested and digested continuously (unidirectional flow) |
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Mouth |
digestion begins here -salivary amylase: begins carbo breakdown - starches break down to sugar Salivary glands in mouth release saliva for lubrication - cells in the tongue secrete Lingual lipase (begins breakdown of lipids) |
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Esophagus |
food from mouth enters the esophagus - muscular tube connecting mouth and the stomach -propelled to stomach by a wave of muscle contractions (peristalsis) -the system is a reflex; an automatic reaction to a stimulus; that is stimulated by swallowing |
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The bird Crop: |
bird species have a prominent widened segment of esophagus (crop) where food can be stores and sometimes processed - often just a simple storage sac *(adaptations that allows individuals to eat a large amt in a short time, then retreat to a safe location while digestion occurs - Leaf Eating Birds: enlarged crop containing bacteria that helps them break down cellulose -from crop, food enters gizarrd |
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The Stomach:
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bracketed on both ends by sphincters - protein polypeptides; breakdown begins here - muscle contractions; mixing and breaking down food mechanically -churning mixes food with gastric juices, wh/ contains HCI (hydrochloric acid and pepsin (enzyme) to begin protein digestion -chief cells (special stomach cells) contains a pepsin precursor called pepsinogen that is converted to pepsin in presence of HCI -secretion of protein digesting enzyme in inactive form is imp.; prevents destruction of proteins in cells where enzyme is synthesized |
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which cells produce stomach acid?
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1. stomach epithelium contains several types of secretory cells (parietal cells) -source of HCI in gastric juices *helps to denature (unfold) proteins aiding in digestion 2. Mucous cells- secrete mucus, which lines gastric epithelium and protects stomach from damage HCI; ***Reason why stomach doesn't digest itself. |
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Parietal cells |
secretory cells in stomach; source of HCI in gastric juice *carbonic anhydrase is found in high concentrations in parietal cells -catalyzes formation of H2CO3, which immediately dissociates into HCO3- and a proton *protons formed by dissociation of H2CO3 are actively pumped into stomach lumen; proton combines with CI- from blood....transported into lumen via CI-channel |
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carbonic anhydrase |
carbonic anhydrase is found in high concentrations in parietal cells-catalyzes formation of H2CO3, which immediately dissociates into HCO3- and a proton ...catalyze carbon dioxide? |
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who is Dr. William Beaumont?
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Lumen of stomach is highly acidic; predominant acid in the stomach is hydrochloric acid (HCl) -Protein digestion begins in stomach -Much of knowledge of digestion in stomach came from Dr. William Beaumont (1785–1853), who nursed a gunshot victim (Alexis St. Martin: gunshot wound left a hole into his stomach) back to health |
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Ulcers are an infectious disease....
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Hole in an epithelium that damages underlying basement membrane and tissues -Ulcers were initially thought to result from excess acid in stomach -Ulcers were caused by a bacterium called Helicobacter pylori- This finding makes ulcers an infectious disease |
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What is a Ruminant stomach?
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complex 4 chambered stomach specialized for digesting cellulose rather than protein; cows - the largest chamber is a Rumen |
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path of food flow in a ruminant stomach
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1. food enters rumen and 2. reticulum - fermentaion occurs (cellulase in bacteria/protists breaks up cellulose into glucose. 3. food is regurgitated (cud) and chewer further than it enters omasum - water and minerals are absorbed 4. food enters the Abomasum- corresponds to true stomach and contains its own digestive enzymes (e.g. pepin) |
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describe the Avian modified stomach
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Gizzard: Another type of modified stomach -Birds do not have teeth & cannot chew -Many species swallow sand/small stones... pulverize food as muscular gizzard contracts -Gizzard (and cud) are both interpreted as adaptations allowing animals to ingest food quickly and digest it later (survival) |
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Where does major digestion take place?
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small intestine - 6 meters long; partially digested food passes from stomach into the small intestine -food mixes with secretions from pancreas & liver & begins to move thru tube. - end of SI = digestion is complete & most nutrients & H2O have been absorbed - enourmous SA for absorption of nutirents due to projections called Villi; *Villi have projections called microvilli *each villi conatins blood vessels, nutirents then pass quickly from epithelial cells into body's transport systems. |
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describe the digestion of proteins in the small intestine |
Pancreatic enzymes in small intestine (proteases) digest polypeptides to monomers Many types of proteases -Each specific for a different kind of polypeptide |
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Carbohydrate digestion and transfer
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Pancreas also produces enzymes for digestion of DNA, RNA, carbohydrates -Nucleases digest RNA and DNA Pancreatic amylase continues carbohydrate digestion (from mouth) |
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what is the function of the large intestine?
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When digested material reaches large intestine, a large amount of H2O & virtually all available nutrients have been absorbed Primary function of large intestine: Compact wastes that remain Absorb enough water to form feces Feces are held in rectum, final part of large intestine, until they can be excreted the transmembrane water channel Aquaporins, play a mj role in H2O movement in large intestine |
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what is the variation of function and form in the large intestine?
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Size and function of large intestine varies dramatically -Fishes have no large intestine -Plant-eating species have extremely large colons -In amphibians, reptiles, and birds, the urine and feces both empty into an enlarged portion of large intestine (cloaca) |
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what is the role of the cecum & appendix?
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In herbivores, the cecum is -An outpocketing of the digestive tract -Located at beginning of large intestine -Fermentation chamber for processing cellulose (contains symbiotic bacteria) -In humans, cecum is dramatically reduced in size -Because size & function differ from those of a cecum, it is called the appendix |
