Digestion and Food Processing

Flashcards for reviewing digestive systems

Differentiate between herbivores, carnivores, and omnivores.

Herbivores eat only plants and have longer digestive tracts; Carnivores eat other animals and have shorter, acidic digestive tracts; Omnivores eat both plants and animals with combined digestive features.

What are the 4 steps of food processing? Define each.

Ingestion: eating; Digestion: breaking down food (mechanical & chemical); Absorption: nutrient uptake; Elimination: waste removal.

List feeding mechanisms & examples.

Filter feeding (whales): strain particles; Substrate feeding (caterpillars): live on/in food; Fluid feeding (mosquitoes): suck fluids; Bulk feeding (humans): eat large pieces.

Define digestion and contrast mechanical and chemical digestion.

Digestion is the breakdown of food. Mechanical digestion involves physical processes like chewing, while chemical digestion involves enzymatic breakdown of macromolecules.

What is the significance of compartmentalized processing in digestion?

Allows digestion to occur in specialized organs, increasing efficiency and avoiding self-digestion.

Compare intracellular and extracellular digestion.

Intracellular: food is digested inside cells (e.g., sponges). Extracellular: food is broken down outside of cells in a digestive cavity (e.g., humans).

What is the difference between a gastrovascular cavity and an alimentary canal?

Gastrovascular cavity has one opening for ingestion/elimination (e.g., cnidarians). Alimentary canal has two (mouth and anus) with specialized compartments (e.g., humans).

What is the first structure food enters during digestion and its function?

The mouth. It ingests food and starts mechanical digestion via teeth and chemical digestion via saliva (amylase for starch).

What are the main digestive enzymes in the stomach and their functions?

HCl denatures proteins and breaks down extracellular matrices. Pepsin cleaves peptide bonds in proteins.

Trace the path of food through digestion (Mouth -> Stomach -> Pancreas -> Small Intestine)

Mouth: carb digestion via amylase -> Stomach: protein digestion via pepsin -> Pancreas: produces enzymes & bicarbonate -> Small intestine: most digestion and absorption.

Why is the size of the small intestines different in herbivores and carnivores?

Herbivores need longer intestines for cellulose breakdown. Carnivores digest meat more quickly and have shorter intestines.

What is the final part of the digestive tract and its function?

Large intestine: absorbs water/electrolytes, compacts feces.

Describe the structure and function of the large intestine.

Includes cecum, colon, rectum, anal canal. It reclaims water and propels waste via peristalsis.