Animal Digestion & Nutrition

Flashcards covering key vocabulary related to animal digestion and nutrition.

Animal Nutrition

The process where food is taken in, broken apart, and absorbed by animals.

Herbivores

Animals that primarily consume plants or algae.

Carnivores

Animals that primarily consume other animals.

Omnivores

Animals that regularly consume both animals and plants or algae.

Opportunistic Feeders

Animals that feed on whatever food source is available.

Diet

The combination of food and liquid ingested by an organism for survival, growth, and health.

Metabolism

The sum of all metabolic activities of an organism or cell.

Catabolism

The breakdown of macromolecules into monomers, utilizing hydrolysis.

Anabolism

The synthesis of macromolecules from monomers, utilizing dehydration synthesis.

Carbohydrates

Organic molecules that store energy, provide structural support, and are based on the formula (CH2O)n.

Starch & Glycogen

A compact form of long-term energy storage.

Cellulose

An important structural polysaccharide used for cellular structures, primarily in plant cell walls.

Chitin

A polysaccharide occurring in the cell walls of fungi, some algae, arthropods, and cephalopods.

Monosaccharides

Simple sugars that provide chemical energy to cells and serve as building blocks for larger molecules.

Glucose

The primary energy currency in the cell, converted from glucose during cellular respiration.

Carbohydrate Polysaccharides

Used for energy storage, structural support, cell recognition, and synthesis of other molecules.

Lipids

Hydrophobic molecules consisting primarily of carbon and hydrogen.

Lipoproteins

Transport cholesterol through the bloodstream.

High-density lipoprotein (HDL)

Transports cholesterol from the tissues to the liver for excretion.

Low-density lipoprotein (LDL)

Carries cholesterol from the liver to the tissues.

Triglycerides (Fats)

Store chemical energy; also called triacylglycerols or triglycerides.

Glycolysis

Breaks down glucose into two molecules of pyruvate.

Pyruvate oxidation

Turns pyruvate into Acetyl CoA.

Electron Transport chain

Accounts for most of the ATP synthesis.

Cellular respiration

The breakdown of food resources to produce ATP.

Anaerobic

Occurs after glycolysis when oxygen is not present.

Electron transport chain

Transports Electrons from food.

Filter feeders

Sift small food particles from the water.

Substrate feeders

Consume foods on which they live.

Fluid feeders

Drink nutrient-rich fluids.

Bulk feeders

Ingest large pieces of food.

Ingestion

bringing food resources into the digestive system

Digestion

breaking down the food resources into units small enough for the body to be able to utilize

Absorption

transfer of the nutrients from the digestive tract into cells and/or other body organs/systems

Elimination

removal of any indigestible, unusable or excess food resources

Mechanical digestion

Increases the surface area of food during digestion.

Chemical digestion

Splits food into small molecules that can pass through membranes.

Intracellular digestion

Occurs within cells, involving phagocytosis or pinocytosis.

Gastrovascular cavity

System for external digestion with one opening.

Alimentary canal

System for external digestion with two openings.

Stomach / Crop / Gizzard

Site for storage and mechanical digestion

Small Intestine / Intestine / Gastric Cecae

Site for enzyme digestion & the site of absorption of nutrients

Large Intestine / Hindgut / Rectum / Anus

Site for absorption of excess H2O

Oral cavity (mouth)

Where food enters; involves teeth mastication and saliva secretion.

Pharynx

opening between the oral cavity and esophagus

Epiglottis

prevents bolus from entering trachea

Esophagus

moves food to stomach through peristalsis

Stomach

Major site of mechanical and chemical digestion with gastric juice.

Parietal cells

Secrete hydrogen and chloride ions separately into the lumen (cavity) of the stomach

Chief cells

Secrete inactive pepsinogen, which is activated to pepsin when mixed with hydrochloric acid in the stomach

Mucus

Protects the stomach lining from gastric juice

Small Intestine

Site of nutrient absorption (water, amino acids, fatty acids, monosaccharides, vitamins and minerals).

Digestion & Absorption of nutrients Small intestine

Pancreatic secretions and liver bile are secreted into the duodenum

Digestion & Absorption of nutrients

Nutrients absorbed = monomers (monosaccharides, amino acids, fatty acids) and vitamins and minerals

Pancreas

Has exocrine role which includes secreting amylase, protease, and lipase. also has endocrine role which includes secreting insulin, glucagon

Gall bladder

Stores bile from liver which emulsifies lipids

Insulin

Acts on nearly all body cells to stimulate glucose uptake from blood

Large intestine

Colon is connected to the small intestine to recover water that has entered the alimentary canal.

Colon

Bacteria (e.g., Escherichia coli) lives on unabsorbed organic material and produces vitamins

Dentition

An animal’s assortment of teeth is one example of structural variation reflecting diet

Crop

Reservoir with past esophagus: stores and moistens food

Gizzard

Stomach compartment that grinds food

Gastroliths

Stones in the stomach or gizzard that aid in grinding action

Bacteria

Involves mutualistic symbiosis

Microbiome

The collection of the microorganisms living on the body

Duodenum

First portion of the small intestine where digestion primarily takes place.

Jejunum

Second portion of the small intestine where absorption primarily takes place.

Ileum

Third portion of the small intestine where absorption primarily takes place.

Amylase

Enzyme in saliva that digests starch and glycogen.

Pepsin

Enzyme that cleaves proteins into smaller peptides in the stomach.

Pepsinogen

Inactive form of pepsin, activated by hydrochloric acid in the stomach.

Hydrochloric acid (HCl)

Acid secreted by parietal cells in the stomach to kill bacteria and denature proteins.

Gastric juice

Substances secreted by cells in the stomach, including hydrochloric acid and pepsin

Enzymatic Hydrolysis

The process of enzymatic hydrolysis splits bonds in molecules with the addition of water

Pharynx

Opening between the oral cavity and esophagus

Epiglottis

Prevents the bolus from entering the trachea (windpipe)

Protease

A protease, or protein-digesting enzyme, that cleaves proteins into smaller peptides

Ruminants

First fermented by bacteria in the rumen after ingestion and then regurgitated for further chewing and enzymatic digestion

Earthworm digestive organs

Esophagus, crop, gizzard

Grasshopper digestive organs

Midgut, esophagus, crop, mouth, stomach, gizzard, intestine, anus

Bird digestive organs

Anus, rectum, esophagus, crop, hindgut, foregut, mouth, gastric cecae

Earthworm crop

Stores and moistens food

Earthworm gizzard

Stomach compartment that grinds food

Pancreatic trypsin and chymotrypsin

Produce smaller polypeptides in the small intestine

Omnivore digestive system

Digestive system is intermediate between herbivores and carnivores, reflecting a mixed diet