Heterotrophic Nutrition

Heterotrophic Nutrition• Organisms that obtain food are

heterotrophs• Ingestion- Taking in food• Digestion- Breaking down food

2 Types:1. Intracellular digestion- digestion inside a single cell (unicellular organisms)2. Extracellular digestion- digestion within a system (multi-cellular organisms). Ex) Inside the stomach and small intestine

• Egestion- Removal of undigested food (solid wastes)

Mechanical vs. Chemical Digestion

• Mechanical Digestion- Physical breakdown (teeth cut, tear, grind, and chew food in mouth)– Also occurs in stomach– provides large surface area for chemical digestion!

• Chemical Digestion a.k.a Enzymatic Hydrolysis- Chemical breakdown with water and enzymes.With enzymes, organic compounds like carbs, proteins, and lipids are broken into their USABLE NUTRIENTS!

Human Nutrition• Nutrition- Those activities by which

organisms obtain and process nutrients

• Nutrients- Usable parts of food• Nutrients Absorbed without digestion:

VitaminsMineralsWater

Six Main Nutrients

Absorbed without digestion: Water

Vitamins Minerals

Absorbed with digestion:

Carbs. glucose

Proteins amino acids Lipids

glycerol & fatty acids

Roughage- Fiber, indigestible food that contains celluloseEx) fruits, vegetables, whole grains

The Path of Food

Mouth – Salivary amylase – Carbohydrate digestion– Mechanical & chemical digestion

Esophagus –No digestion–Peristalsis starts-involuntary muscle contractions push food down

Stomach –Muscular–Acidic gastric juice–Protein digestion–Mechanical & Chemical

Small intestine– Chemical digestion– Carbs, Proteins & Lipids– Nutrient Absorption– Contain villi– Villi- Contain cappilaries, increase surface area

The Intestines

Large IntestineNo digestion hereWater is reabsorbed

Accessory OrgansFood does not pass through

• Liver- makes bile to emulsify fats/lipids

• Gall Bladder- Stores bile

• Pancreas- provides the small intestine with protease, lipase, amylase (enzymes)

• What kind of digestion does this organism perform?

• What substance produced by the liver performs emulsification?

• Is emulsification mechanical or chemical digestion?

• Where does all nutrient absorption occur?

• Name the finger-like projections surrounded by capillaries found in the Sm. Intestine?

• Name the process occuring here in the esophagus.

• Does digestion occur here?

• Which organ produces acidic gastric juice?

• What compound is broken down there?

Malfunctions of the Digestive System

HeartburnGastric juice enters esophagusTreat with medicine

GallstonesHardened Cholesterol

Ulcersopen sores inside of stomach

Treated with antacids, diet, surgery.

AppendicitisInflammation of Appendix.

Can be removed

• Constipation- Difficulty with egestion because too much water is reabsorbed by L.I.

• Diarrhea- Causes dehydration, not enough water is reabsorbed by L.I.

Indicators:Indicate the presence of a

substance in a mixture pH Paper/Litmus Paper:

Indicates pH Blue Benedict’s Solution:

Indicates presence of monosaccharides (glucose)

Color Change Blue Orange/Red

must heat

Lugol’s Iodine Solution:

Indicates polysaccharides (starch)

Color Change Brown Blue/Black

Unglazed Paper:

Indicates lipids

Turns translucent (clear)

Digestive System Journey

Digestive System