Digestive and Circulatory Systems Collaboration in Nutrient Transportation

1. Complete unit planner by writing today’s activities and homework in the appropriate spaces. Answer the following question as today’s bellringer: Think back over our study of the circulatory system. It’s major purpose was to transport needed materials to cells and tissues throughout the body. How might the circulatory system and the digestive system work together to accomplish this?

2. - Food and Energy Carbohydrates • In addition to providing energy, carbohydrates provide the raw materials to make cell parts.

3. - Food and Energy Fats • Many foods contain saturated, unsaturated, and trans fats. Unsaturated fats are considered to be more healthful than saturated fats and trans fats.

4. - Food and Energy Proteins • Proteins are needed for tissue growth and repair. They also play an important role in chemical reactions within cells.

5. - Food and Energy Vitamins and Minerals • Vitamins act as helper molecules in a variety of chemical reactions in the body.

6. - Food and Energy Vitamins and Minerals • Nutrients that are not made by living things are called minerals. • Minerals are present in soil and are absorbed by the roots of plants. • Thus, how do you obtain minerals in your diet?

7. - Food and Energy Water • Water is the most important nutrient because the body’s vital processes – including chemical reactions such as the breakdown of nutrients – take place in water.

8. - The Digestive Process Begins Functions of the Digestive System • The digestive system has three main functions. First, it breaks down food into molecules the body can use. Then, the molecules are absorbed into the blood and carried throughout the body. Finally, wastes are eliminated from the body.

9. - The Digestive Process Begins Methods of the Digestion • Mechanical digestion – foods are physically broken down into smaller pieces • Chemical digestion – chemicals produced by the body break down foods into their smaller chemical building blocks

10. - The Digestive Process Begins The Mouth • Both mechanical and chemical digestion begin in the mouth.

11. - The Digestive Process Begins The Mouth • The shape of an enzyme molecule is specific to the shape of the food molecule it breaks down. Here an enzyme breaks down a starch into sugars.

12. INDEPENDENT PRACTICE… Draw a Venn diagram comparing and contrasting mechanical and chemical digestion.

13. TICKET OUT… Which of the following activities represent mechanical digestion and which represent chemical digestion: 1. The teeth cut and grind food2. The stomach churns food3. Enzymes in saliva break down carbohydrates in food4. Enzymes break down proteins in food

14. - The Digestive Process Begins Protein Digestion • A scientist performed an experiment to determine the amount of time needed to digest protein. He placed small pieces of hard-boiled egg white (a protein) in a test tube containing hydrochloric acid, water, and the enzyme pepsin. He measured the rate at which the egg white was digested over a 24-hour period. His data are recorded in the graph.

15. Percentage of egg white digested Reading Graphs: What do the values on the y-axis represent? - The Digestive Process Begins Protein Digestion

16. About 14 hours Interpreting Data: After about how many hours would you estimate that half of the protein was digested? - The Digestive Process Begins Protein Digestion

17. About 70% Interpreting Data: How much digestion occurred in 16 hours? - The Digestive Process Begins Protein Digestion

18. From 13 to 16 hours Drawing Conclusions: During which four-hour period did the most digestion take place? - The Digestive Process Begins Protein Digestion

19. Complete unit planner by writing today’s activities and homework in the appropriate spaces. Answer the following question as today’s bellringer: Describe as best you can the process that turns food into nutrients that cells can use.A Great Illustration of Digestion

20. - The Digestive Process Begins The Epiglottis and the Esophagus • The epiglottis is flap of cartilage located in the throat behind the tongue and in front of the larynx. • When a person swallows the epiglottis folds backward to cover the entrance of the larynx so food and liquid do not enter the windpipe and lungs.

21. - The Digestive Process Begins The Epiglottis and the Esophagus • The esophagus is a muscular tube that extends from the neck to the abdomen and connects the back of the throat to the stomach. • The esophagus squeezes the mass of food with rhythmic muscle contractions called peristalsis. Peristalsis forces the food into the stomach. • Peristalsis Demo

22. - The Digestive Process Begins The Stomach • Most mechanical digestion and some chemical digestion occur in the stomach.

23. - Final Digestion and Absorption “The Stomach” Mechanical and chemical digestion takes place in the stomach. Tiny glands in the stomach produce enzymes and acid. Food is reduced to a soupy mixture called chyme. Food is squeezed by muscular contractions.

24. - Final Digestion and Absorption The Small Intestine • The small intestine is the part of the digestive system where most chemical digestion takes place.

25. - Final Digestion and Absorption The Small Intestine • Tiny finger-shaped projections called villi line the inside of the small intestine. Villi absorb nutrient molecules. The molecules pass from the villi into blood vessels.

26. - Final Digestion and Absorption “The Small Intestine” Chemical digestion takes place in the small intestine. Starches, proteins, and fats are digested chemically. Enzymes and secretions are produced by the small intestine, liver, and pancreas. Food mixes with enzymes and secretions.

27. - Final Digestion and Absorption The Large Intestine • Most commonly known as the colon…

28. Graphic Organizer In the mouth, the teeth break food into smaller pieces and saliva begins to break down starches. Esophagus pushes food from mouth to stomach. In the stomach, food is churned and mixed with digestive juices that break down protein. In the small intestine, almost all chemical digestion and absorption occurs. Large intestine absorbs water and eliminates waste.

29. TICKET OUT… Identify each of the following statements as true or false… 1. Digestion begins when food reaches the stomach.2. Breaking, crushing, and mashing food is an example of chemical digestion.3. Saliva contains enzymes, which begin the chemical digestion of food.4. The esophagus connects the mouth with the small intestine directly.