Animal Nutrition I Ch 41 Keywords Heterotroph Autotroph

Animal Nutrition I (Ch. 41)

Keywords • • Heterotroph Autotroph Herbivore Carnivore Omnivore Intracellular digestion Food vacuole Extracellular digestion • Gastrovascular cavity • Alimentary canal • Basic parts of alimentary canal • Roles of mouth and stomach in digestion

Some of the best known and fascinating adaptations of animals involve their feeding and digestion

Examples: • Reptile swallowing prey • Baleen whales

Python

Starfish

Chiasmodon niger

Cryptopsaras couesi

Eurypharynx pelecanoides

Categories • I. Autotroph • II. Heterotroph – A. Herbivore – B. Carnivore – C. Omnivore

Today we’ll focus on heterotrophs: Digestion • Basic principles • Invertebrates • Humans

Why is digestion necessary? • Macromolecules cannot easily enter cell COO- NH 3+ cytoplasm peptide Cell membrane

Small molecules such as amino acids can cytoplasm Peptide being digested Cell membrane

cytoplasm Peptide being digested Cell membrane

cytoplasm Peptide being digested Cell membrane

cytoplasm Peptide being digested Cell membrane

cytoplasm Digested peptide Cell membrane

Even if macromolecules are taken in… COO- NH 3+ cytoplasm peptide Cell membrane

Even if macromolecules are taken in… cytoplasm COO- peptide Cell membrane NH 3+

They cannot be readily incorporated cytoplasm COO- Food peptide Cell membrane NH 3+ New peptide

Unless broken down first cytoplasm Food peptide Cell membrane New peptide

Unless broken down first cytoplasm Food peptide Cell membrane New peptide

Unless broken down first cytoplasm Food peptide Cell membrane New peptide

This lecture will focus on how animals break down food • I. Intracellular digestion – A. food vacuoles • II. Extracellular digestion – A. outside organism – B. gastrovascular cavity – C. alimentary canal

I. Intracellular digestion • A. food vacuoles

Intracellular digestion without vacuoles

Intracellular digestion without vacuoles

Intracellular digestion with vacuoles

Intracellular digestion with vacuoles

Intracellular digestion with vacuoles

Digestion in Paramecium

Intracellular digestion vs. Extracellular digestion

Extracellular digestion • A. outside organism • B. gastrovascular cavities • C. alimentary canal

Extracellular digestion • A. outside organism • B. gastrovascular cavities • C. alimentary canal

Gastrovascular cavity: Hydra

Extracellular digestion • A. outside organism • B. gastrovascular cavities • C. alimentary canal

Gastrovascular cavity vs. Alimentary Canal

Alimentary canal: a simple view

Basic parts of alimentary canal Mechanical digestion mouth storage absorption anus

Alimentary canal: mammalian

Mouth • Mechanical • enzymatic

Stomach

Digestive mechanisms in stomach • Mechanical • Chemical • enzymatic