Lecture #10 - Animal Nutrition and Digestion

Lecture #10 - Animal Nutrition and Digestion

Lecture #10 Animal Nutrition and Digestion 1 Key Concepts: Animals are heterotrophic! Nutritional needs what animals get from food Food processing The human digestive system

2 Critical Thinking Is this animal approaching the fruit or the flower??? Why??? 3 Critical Thinking Is this animal approaching the fruit or the flower???

Why??? 4 Animals are always consumers Only photosynthesis can convert solar energy to usable chemical energy Plants store chemical energy Animals eat plants (or other animals) .of course this is somewhat simplified. but NO animals are autotrophic

5 Critical Thinking Why do we eat??? Specifically, what do we get from food??? 6 Critical Thinking Why do we eat??? Specifically, what do we get from food???

7 Why we eat energy Animals generate ATP by aerobic respiration Main substrate is carbohydrates Fats are also used Proteins are used as a last resort Digestion converts consumed polymers to the monomers used in respiration

8 Remember bioenergetics Managing the energy budget is essential to maintaining animal function ATP powers basal metabolism, other activities; maintains homeostasis; etc Animals must eat to

make ATP Diagram bioenergetics and the fate of food 9 Why we eat carbon skeletons Animals need organic carbon scaffolds to build our own organic molecules such as???

10 Why we eat carbon skeletons Animals need organic carbon scaffolds to build our own organic molecules such as 11 Why we eat essential nutrients Molecules that animals cannot make at all Do not have the right biosynthetic pathways

Must be eaten in pre-assembled form Some common to all animals; some specialized Essential amino acids Essential fatty acids Vitamins Minerals 12 Essential Amino Acids Most animals use the same 20 amino acids

to make what??? 13 Essential Amino Acids Most animals use the same 20 amino acids to make Most animals can only synthesize about half Remaining amino acids must be consumed All animal proteins are complete contain all the essential amino acids

All plant proteins are incomplete missing some of the essential amino acids 14 Human vegetarian diets must mix plant groups to obtain all essential amino acids Chart essential amino acids; overlap between grains and legumes 15 Grains and legumes mixed provide all essential amino acids cultural traditions prevent protein deficiencies

Essential Fatty Acids Some unsaturated fatty acids cannot be synthesized Most animals (especially humans!) get adequate essential fatty acids from their diet We use fatty acids for???? 16 Essential Fatty Acids Some unsaturated fatty acids cannot be

synthesized Most animals (especially humans!) get adequate essential fatty acids from their diet We use fatty acids for 17 Vitamins Organic molecules used in small quantities Water soluble vitamins usually function as coenzymes

Fat soluble vitamins function in nutrient absorption, as antioxidants, etc.. Deficiencies are rare with an adequate, balanced diet 18 Critical Thinking Which category of vitamin is more likely to accumulate and become toxic water soluble or fat soluble??? Why???

19 Critical Thinking Which category of vitamin is more likely to accumulate and become toxic water soluble or fat soluble??? Why??? 20 Table essential vitamins; sources and functions Study

table in text for a general understanding 21 Minerals Inorganic elements Some required in small amounts; some in larger

Requirements vary by taxon Many different functions Some metabolic; some structural Know top 8 minerals and their main functions 22 Mineral Functions???

Calcium Phosphorous Sulfur Potassium Chlorine

Sodium Magnesium Iron 23 Some Mineral Functions

Calcium Phosphorous Sulfur Potassium Chlorine Sodium Magnesium Iron 24

Food Processing Absorptio n Eliminatio Diagram food procession in a small mammal n Ingestion Digestion 25

Evolution of Compartmentalization Food digestion must be contained Why??? Earliest containment structures are food vacuoles Sponges digest entirely intra-cellularly Most animals digest at least partly outside the cells Simplest body plans have a digestive sac with one opening

More complex animals have a digestive tube with an opening for ingestion and one for elimination 26 Evolution of Compartmentalization Food digestion must be contained Earliest containment structures are food vacuoles Sponges digest entirely intra-cellularly Most animals digest at least partly outside the cells

Simplest body plans have a digestive sac with one opening More complex animals have a digestive tube with an opening for ingestion and one for elimination 27 Evolution of Compartmentalization Food digestion must be contained Earliest containment structures are food vacuoles Sponges digest entirely intra-cellularly

Most animals digest at least partly outside the cells Simplest body plans have a digestive sac with one opening More complex animals have a digestive tube with an opening for ingestion and one for elimination 28 Sponges digest food in vacuoles that fuse with lysosomes containing hydrolytic enzymes Diagram sponges and their choanocytes

29 Evolution of Compartmentalization Food digestion must be contained Earliest containment structures are food vacuoles Sponges digest entirely intra-cellularly Most animals digest at least partly outside the cells Simplest body plans have a digestive sac with one

opening More complex animals have a digestive tube with an opening for ingestion and one for elimination 30 Jellies and flatworms start digestion in gastrovascular cavities; finish in food vacuoles Diagram two cell layers in cnidarians Images a jellyfish and a flatworm

31 Jellies and flatworms start digestion in gastrovascular cavities; finish in food vacuoles Problem ??? 32 Evolution of Compartmentalization Food digestion must be contained Earliest containment structures are food

vacuoles Sponges digest entirely intra-cellularly Most animals digest at least partly outside the cells Simplest body plans have a digestive sac with one opening More complex animals have a digestive tube with an opening for ingestion and one for elimination 33

Hands On Be sure to examine specimens and comment on structure-function relationships Be sure to examine Cnidarians at the aquarium and comment on structurefunction relationships 34 Evolution of Compartmentalization Food digestion must be contained Avoids digestion of body cells and tissues

Earliest containment structures are food vacuoles Sponges digest entirely intra-cellularly Most animals digest at least partly outside the cells Simplest body plans have a digestive sac with one opening More complex animals have a digestive tube with an opening for ingestion and one for elimination 35

Critical Thinking The 2-hole tube body plan processes food sequentially no mixing of incoming food and outgoing waste Can you think of another advantage for the 2-hole tube plan??? 36 Two hole tube digestive plan essentially an open tube that passes through the body

37 Critical Thinking The 2-hole tube body plan processes food sequentially no mixing of incoming food and outgoing waste Can you think of another advantage for the 2-hole tube plan??? 38

Tubular system allows for specialization and efficiency Specialization based on habitat and diet Both divergent and convergent patterns have emerged Diagram development of specialization in 2-hole tubular digestive tracts in

earthworms, insects and birds All mammals have a cecum Both earthworms and birds have developed crops 39 The Human Digestive System Relatively straightforward adaptations to an omnivorous diet

Tube running from mouth to anus with specialized regions for food processing, absorption, and elimination of wastes Accessory glands supply lubrication, digestive enzymes and other secretions Schematic diagram the human digestive system

40 Diagram the human digestive tract 41 Oral cavity, pharynx and esophagus allow for chewing and swallowing food Teeth cut and grind Tongue mixes and pushes bolus to back Saliva lubricates

food, protects the mouth lining, buffers pH, kills bacteria, and begins the digestion of carbohydrates Diagram the oral cavity, pharynx and esophagus; same diagram on next two slides 42

Oral cavity, pharynx and esophagus allow for chewing and swallowing food Epiglottis tips down to direct food from pharynx to esophagus (so you dont breathe your food) Diagram specifically the function of the epiglottis 43 Oral cavity, pharynx and esophagus allow for chewing and swallowing food Peristaltic contractions in

esophagus push food to stomach Food does not fall by gravity remember our quadruped ancestors Sphincter (ring) muscles also control passage of food 44 Stomach continues the action Stores food (very folded and stretchy)

Muscle contractions mix food Lining secretes gastric juice Very acidic (pH ~2) hydrochloric acid dissolves cell matrices and denatures proteins in swallowed food; also kills many ingested bacteria Pepsin begins protein hydrolysis Stomach lining protected from self-digestion by thick mucus and secretion of inactive pepsin precursor Controls passage of food into small intestine 45

Stomach continues the action Stores food (very folded and stretchy) Muscle contractions mix food Lining secretes gastric juice Very acidic (pH ~2) hydrochloric acid dissolves cell matrices and denatures proteins in swallowed food; also kills many ingested bacteria Pepsin begins protein hydrolysis Stomach lining protected from self-digestion by thick mucus and secretion of inactive pepsin precursor

Controls passage of food into small intestine 46 Diagram the somach lining and secreting cells 47 Ulcers.. Stomach lining replaces itself by mitosis about every 3 days Lesions still sometimes occur

Ulcer risk factors??? 48 Ulcers.. Stomach lining replaces itself by mitosis about every 3 days Lesions still sometimes occur Ulcer risk factors 49

Other animals can get ulcers, too From a students extra credit Causes include stress, diet, genetic abnormalities, microbial infections, very finely ground grains, heredity, bile reflux that destroys stomach lining 50 Stomach continues the action Stores food (very folded and stretchy) Muscle contractions mix food

Lining secretes gastric juice Very acidic (pH ~2) hydrochloric acid dissolves cell matrices and denatures proteins in swallowed food; also kills many ingested bacteria Pepsin begins protein hydrolysis Stomach lining protected from self-digestion by thick mucus and secretion of inactive pepsin precursor Controls passage of food into small intestine 51

Diagram the cells lining the stomach, secretion of digestive juices 52 The Small Intestine Completes digestion and absorbs monomers Some absorption occurs in other parts of the digestive tract, but most in the SI

More than 6m long Multiple levels of folding increase SA Surface area about 600m2!! Most digestion occurs in the first 25cm of the small intestine Enzymatic hydrolysis Most absorption occurs in the latter 5.75m of the small intestine

53 Diagram the human small intestine 54 Four levels of folding function to increase surface area tube, interior folds, villi, microvilli Diagram levels of folding in the human small intestine

55 Increased surface area, especially of transport epithelia, is a hallmark of large, complex, multi-dimensional animals Factoids from humans: Lungs have 100 m2 of surface area (almost 1/2 as big as room) Small intestine has surface area of a tennis court 80 km of tubules in a single kidney

100,000 km of blood vessels = almost 3X circumference of earth 56 The Small Intestine Completes digestion and absorbs monomers Some absorption occurs in other parts of the digestive tract, but most in the SI

More than 6m long Multiple levels of folding increase SA Surface area about 600m2!! Most digestion occurs in the first 25cm of the small intestine Enzymatic hydrolysis Most absorption occurs in the latter 5.75m of the small intestine

57 Pancreas secretes enzymes and bicarbonate; liver secretes bile Diagram the pancreas, liver and gall bladder; structure and function 58 Digestive enzymes and substrates Chart digestive enzymes; point of secretion and substrate; same

on next slide 59 Most digestion in duodenum (1st 25cm) 60 The Small Intestine Completes digestion and absorbs monomers Some absorption occurs in other parts of the digestive tract, but most in the SI

More than 6m long Multiple levels of folding increase SA Surface area about 600m2!! Most digestion occurs in the first 25cm of the small intestine Enzymatic hydrolysis

Most absorption occurs in the latter 5.75m of the small intestine 61 Monomers cross into epithelial cells, then into interstitial fluid, then into the lymph or bloodstream Diagram close-up of villi and microvilli Some transport is

facilitated, some active Each villus includes lymph and blood vessels 62 Fat Digestion Diagram fat digestion process; same next

slide Fats are hydrophobic Bile salts emulsify large fat droplets into smaller droplets more surface area Lipase digestion produces fatty acids and monoglycerides These monomers form into micelles 63

Fat Absorbtion Micelles are tiny enough to diffuse into epithelial cells Monomers are recombined into fats in the epithelial cells Fats mix with cholesterol and are coated with proteins Resulting globules are transported into the lymph, and eventually into the

blood (at shoulder ducts) 64 Intestinal blood vessels drain directly into the hepatic portal vein Nutrients get sent straight to the liver for metabolic processing Diagram how blood vessels absorb nutrients; same next slide 65

Intestinal blood vessels drain directly into the hepatic portal vein From the liver, the blood goes straight to the heart for distribution throughout the body 66 Critical Thinking Where will the levels of blood sugar and other nutrients vary the most???

Diagram circulation patterns in humans showing relationship between circulation and major organs 67 Critical Thinking Where will the levels of blood sugar and other nutrients vary the most???

68 The large intestine, AKA the colon Connected to SI at T junction Dead-end of T is the cecum Appendix extends off cecum Cecum functions as fermentation chamber in many animals, especially herbivores Human cecum is small, relatively functionless Appendix contributes to immune function, but is dispensable

Appendix may function to repopulate intestines with beneficial bacteria after intestinal infections 69 Diagrams the cecum in omnivores (humans) vs. specialized herbivores (koalas) 70 The large intestine, AKA the colon Remainder of LI is ~ 1.5m

Main function is to absorb water 7l of fluid is secreted into intestinal lumen Additional water is consumed in diet SI and LI together absorb ~ 90% Inflammation of LI reduces water absorption diarrhea LI also houses both commensal and mutualistic bacteria Live on undigested or unabsorbed materials Produce important vitamins (K, Bs, folic acid, biotin) Some produce stinky gasses as a byproduct of metabolism 71

The large intestine, AKA the colon Final section of LI is the rectum Feces are produced as water is absorbed from waste organic materials Waste includes LOTS of bacteria; cellulose 40% of the dry weight of feces is bacteria Feces are stored in the rectum When the time comes, feces are eliminated through the anus Sphincter muscles control elimination

One is voluntary, one involuntary Some, but not complete control over defecation 72 Diagram the human digestive tract with the large intestine highlighted 73 Diet is a selection pressure Dentition Different tooth shapes for ripping and grinding

Length of small intestine Herbivores typically have much longer SI Other compartments and symbioses Fermentation chambers that house microorganisms that can digest cellulose (animals lack cellulases) Enlarged ceca (first feces are re-eaten) Esophageal pouches (crops in some birds, the stomachs of ruminants) 74

Critical Thinking How might diet affect tooth evolution? Carnivores Herbivores Omnivores 75

Critical Thinking How might diet affect tooth evolution? Carnivores Herbivores Omnivores

76 Ripping, crushing and shredding teeth Diagram differences in tooth structure Biting and grinding teeth Combo of teeth for biting, tearing, grinding and crushing

77 Diet is a selection pressure Dentition Different tooth shapes for ripping and grinding Length of small intestine Herbivores typically have much longer SI Other compartments and symbioses Fermentation chambers that house microorganisms that can digest cellulose (animals

lack cellulases) Enlarged ceca (first feces are re-eaten) Esophageal pouches (crops in some birds, the stomachs of ruminants) 78 Most plant material is tough and fibrous the longer digestive tract

in herbivores allows more time and space for digestion and absorption of both nutrients and water Diagram differences in the digestive tract of carnivore vs. herbivore

79 Cecum in magenta.. 80 Diet is a selection pressure Dentition Different tooth shapes for ripping and grinding Length of small intestine Herbivores typically have much longer SI

Other compartments and symbioses Fermentation chambers that house microorganisms that can digest cellulose (animals lack cellulases) Enlarged ceca (first feces are re-eaten) Esophageal pouches (crops in some birds, the stomachs of ruminants) 81 Extra compartments house symbiotic micro-organisms food is often regurgitated and / or re-consumed

Diagram the digestive system of a cow 82 Review Key Concepts: Animals are heterotrophic! Nutritional needs Energy Carbon skeletons Essential nutrients Food processing

The human digestive system Diet as a selection pressure 83 Hands On Begin your careful dissection of the rat Follow instructions in lab manual

Answer questions on lab handout Be careful, delicate and precise!!!! 84

Recently Viewed Presentations

  • COMPENSATION CONVERSATION TEACHER POSITIONS ONLY erPoint 1 of

    COMPENSATION CONVERSATION TEACHER POSITIONS ONLY erPoint 1 of

    Does the new hire scheduleapply to existing teachers?. TOOL FOR EXTERNAL APPLICANTS:The NEW HIRE schedule is a tool to assist applicants in estimating what they would earn if they join our Denton ISD family. TOOL FOR HR ADMINISTRATORS: Our team...
  • Application Security - eiti.uottawa.ca

    Application Security - eiti.uottawa.ca

    Did we get better? According to IBM X-Force, the annual growth rate in disclosed application vulnerabilities was 60% from 1996 to 2006, and is only 9% from 2006 to 2014.
  • Recherches en pathologie forestière et en génétique des ...

    Recherches en pathologie forestière et en génétique des ...

    Collaborateurs: C Breuil (SCF), DQ Yang (Forintek) Tanguay et al. 2006 Can.J. Microbiol. 52:501-507. La génomique, un outil puissant pour : Étudier le génome individuel ou cribler des populations entières Établir les liens entre des gènes et des caractères souvent...
  • Victorian Curriculum F-10: Drama 7 to 10

    Victorian Curriculum F-10: Drama 7 to 10

    Victorian Curriculum F-10. ... Street dance - structure - one group and then another group - comes from the 'dance-off', urban gangs, A and B, call and response. ... pathways to VCE, increasing specialisation, building on prior learning.
  • Teacher-Learner Relationship in Distance Education Delivery ...

    Teacher-Learner Relationship in Distance Education Delivery ...

    Designing a Mixed-Method Study to Investigate Post-secondary Education Program Participants' Social Inclusion in the Campus Community Seb MacKenzie Prohn, Academic Coordinator University Participant Program Western Carolina University Research questions: How do UP participants conceptualize social inclusion in their campus community?
  • Object movement in the double object construction in British ...

    Object movement in the double object construction in British ...

    Arial MS Pゴシック Calibri Verdana Wingdings 2 Wingdings Times Times New Roman Symbol Office Theme Aspect 1_Aspect 2_Aspect 3_Aspect 4_Aspect Object movement in the double object construction in British English Slide 2 Slide 3 Slide 4 If there is independent...
  • Industrialization 1865 - 1901

    Industrialization 1865 - 1901

    Injunction - a court order whereby one is required to do or to refrain from doing a specified act. ... How were the new industrial unions different from the older trade union? New Unions Emerge. Workers share same complaints about...
  • Quadruple Entendre - Peter Liljedahl

    Quadruple Entendre - Peter Liljedahl

    Quadruple Entendre . Lessons Learned from. NOT teaching in my 8-12 classroom. being in a classroom but NOT as the teacher. teaching in a way that is often considered as NOT teaching. ... the student work space. we are changing...