Digestive System

Amazing Facts  We make 1-3 pints of saliva a day. The average male will eat about 50 tons of food to sustain weight of 150 pounds A horse’s intestines are about 89 feet long

How is the digestive system like a post office?

ANALOGY The digestive system is like a post office it receives mail which is like the food in the digestive system, gets processed, and then is sent out.

FUNCTION Converts large complex molecules (food) into simpler molecules (nutrients) Absorbs nutrients into the bloodstream Removes food/waste out of the body

What gets released when food is broken down into smaller molecules? CELLULAR ENERGY used for cell activities

Organs that work together to break down food

Two Types of Digestion Mechanical digestion (physical change) Chemical digestion (chemical change)

Chemical or Physical change? Mouth (teeth): chewing and grinding – PERISTALSIS Enzymes in saliva (amylase) break down amylose (starch) into sugars Stomach: Pepsin breaks down proteins with the help of HCl Small intestine: Villi absorbs nutrients Bile (from liver) breaks down fats into smaller fat parts Other enzymes further break down fats into fatty acids Other enzymes further break down proteins into amino acids Lactase breaks down lactose into glucose and galactose Large intestine: absorbs water Liver: Catalase breaks down H2O2 (toxin) into water and oxygen Physical Chemical Chemical Physical Physical Digestion take place through the interactions of enzymes, stomach acid, hormones, bile from the liver, and a network of nerves and muscles. Chemical Chemical Chemical Physical Chemical

Where in the body are biomolecules digested? Mouth Salivary amylase breaks down starch into simple sugars-disaccharides Esophagus Muscles contract to push food through - PERISTALSIS Liver Produces bile that physically breaks down fat (lipids) Stomach Pepsin and HCl acid break down proteins Small Intestine Nutrients are absorbed into the blood (peristalsis) Lipids  Fatty acids Large Intestine Removes excess water and salt

If you ate a meal of spaghetti and meatballs, what type of digestion would occur? Biting and chewing Mechanical Digestion Amylase breaking down starch Chemical Digestion Pepsin breaking down proteins Chemical Digestion Lipids breaking down into fatty acids Chemical Digestion

Chemical or Physical Change? Mechanical or Chemical Digestion? Mouth Chewing & Grinding Salivary amylase breaks down starch  disaccharides (sugars) Stomach Smooth muscle contractions churn food Pepsin and HCl break down proteins Small Intestine Muscular contractions break down and mix food with digestive enzymes like bile Enzymes, bile finish digestion of sugars, proteins (amino acids) and lipids (fatty acids) PHYSICAL CHANGE CHEMICAL CHANGE MECHANICAL DIGESTION CHEMICAL DIGESTION

Why do our body systems interact with each other? To maintain homeostasis

Interactions with Circulatory System The circulatory system transports nutrients absorbed from the small intestine to all the body cells

In cells, nutrients are broken down into even smaller parts by lysosomes, which contain digestive enzymes

Interactions with Muscular System Muscles contract to help chew and swallow food Smooth muscles such as your stomach contracts to push food through

Interactions with Endocrine System Makes the hormone insulin to regulate blood sugar

Interactions with Excretory System Cells produce waste ↓ Enter the blood stream Travel to kidneys Kidneys filter the blood Turns into urine and exits

Interactions with Nervous System Sends messages to digestive system when hungry, full. Signals peristalsis in digestive tract. Signals enzymes/hormones to be released.

Interactions with Respiratory system Digestive system provides carbs for cellular respiration, which needs oxygen to convert it into ATP

Digestion of carbohydrates begins in the - stomach small intestine mouth pharynx

Salivary amylase breaks down _________ into _________ in the _________. Proteins; dipeptides; stomach Lipids; fatty acids & glycerol; small intestine Carbohydrates; sugars; stomach Carbohydrates; sugars; mouth

Proteins that catalyze biochemical reactions are? amino acids enzymes substrates chyme

Digestion of lipids begin in the? mouth small intestine stomach large intestine

Pepsin breaks down _______ in the _______? Proteins; small intestine Carbohydrates; mouth Proteins; stomach Lipids; stomach

Meat from a hamburger begins digestion in the? Mouth Stomach Small intestine Large intestine

Chemical digestion does not occur in the? Mouth Stomach Small intestine Large intestine

Pepsin and _______ chemically breaks down proteins in the stomach. Trypsin Amylase Hydrochloric acid Bile

Which of the following is an example of a chemical change? Absorption of water from your intestine into your bloodstream A pot of water boiling on the stove Adding chocolate chips to batter to make chocolate chip cookie dough Digesting a sugar cube Dissolving cherry Kool-Aid into a glass of water

Which of the following is not a physical change? Ice melting when its left out on a table Corn being ground to make a masa for tamales Dissolving of sugar into glass of ice tea Peristalsis in your esophagus and small intestines Saliva starting the breakdown of starch into sugars in your mouth