1. CHAPTER 3 Health, Nutrients, and Digestion Riley Kelfer B Block

2. Ch. 3-1 Overview  In food, the substances that provide energy and raw materials for the body’s use are called nutrients.  Without them, the body would not be able to carry out its essential functions and processes.  The 6 types of nutrients are carbohydrates, lipids, proteins, vitamins, minerals, and of course- water.  The amount of energy released by nutrients when used by the body is measured by calories.

3. Ch. 3-1 Carbohydrates  Hydrogen, oxygen, and carbon are the elemental constituents of carbohydrates.  All carbs provide energy and materials to the body, but because their chemical makeup may differ, they are ÷.  Complex carbs include starches and fibers, and are made of many sugar molecules linked in a chain.  Simple carbs such as the natural glucose and sugar substitutes like maltodextrin provide quick energy.

4. Ch. 3-1 Lipids  Lipids usually contain about twice the amount of energy as carbohydrates and are also made of C H O.  Fat tissue from lipids play an important role in protecting the body’s internal organs from injury.  One type of fat is unsaturated fat, and it includes mostly liquids like olive and canola oil.  Another type of fat is saturated fat, which includes mainly animal and dairy products as well as some oils.

5. Ch. 3-1 Proteins  Comprised of carbon, hydrogen, oxygen, and nitrogen, proteins help carry out various processes in the body.  Some examples of protein-rich foods are fish, meats, nuts, legumes, and dairy products.  Amino acids are the smalls structures that make up proteins. Some acids are necessary, while some aren’t.  Our body can only produce ≈half of the 20 amino acids, so we must get the others from foods.

6. Ch. 3-1 Vitamins  Vitamins come in many forms and provide various specialized functions within the body.  Vitamins are important in aiding chemical reactions that take place in the body.  Vitamins also come in many different forms- in fruit, vegetables, meats, eggs, dairy et cetera.  Although the body does not need much of a single nutrient, it is important to get some from each of them.

7. Ch. 3-1 Minerals  Some minerals that are essential to the body’s functions are calcium, potassium, sodium and so forth.  Minerals are not made by living things, but rather by the soil and earth.  In order to get these minerals, one has to eat plants that absorb the minerals along with water through roots.  Each mineral performs a specific job, so just like vitamins, the body needs a bit of all of them.

8. Ch. 3-1 Water  Water is the most copious substance in the body. It aids in chemical reactions and many other functions.  The breakdown of nutrients and and the body’s vital functions take place in water.  The body’s fluids, such as blood and lymph also contain a vast majority of water.  In addition, the other nutrients are dissolved in water making it very important in staying healthy.

9. Ch. 3-2 Overview  The Food Pyramid includes 6 categories of food; their size representing how much you should eat each day.  A healthy diet includes all the categories of the food pyramid with an emphasis of fruits, vegetables, and grains.  It is also important to read food labels so that you can be aware of your calorie intake. This also applies to excessive amounts of sugar and polyunsaturated fats.

10. Ch. 3-2 Food pyramid  One should eat the most amount of grains such as pasta to provide energy.  Although it is important to limit the intake of foods from the meats group, as they are high in fats.  Fruits and vegetable often have many vitamins and minerals in them, but fruits also have lots of sugar.  Instead of focusing on one food group, it is important to eat a varied diet across the groups.

11. Ch. 3-2 Food labels  Food labels are a way to look at the nutritional facts for a certain food.  In addition, one can compare two products using their individual nutrition facts.  When observing the ‘ingredients’ section, the first ingredient listed is the most abundant in the product.  A good rule of thumb for ingredients is: if you can’t pronounce it, it is probably not very healthy.

12. Ch. 3-3/Ch. 3-4 Overview  Function: It breaks down food into smaller molecules usable by the body.  Function2: Molecules are absorbed into the blood in the process of absorption in the small intestine.  Function3: Unusable wastes are eliminated from the body.  Food flows throughout each of the organs of the digestion system in peristalsis.

13. Ch. 3-3 The Mouth  All foods starts its journey through the digestive system in the mouth.  Different types of teeth help to mash up and tear food into manageable sizes.  Mastication is an example of mechanical (or physical) digestion.  Salivary glands secrete enzymes which break down food through chemical digestion.

14. Ch. 3-3 The Esophagus  After the tongue and palate roll the food into ball- shaped structure called a bolus, the esophagus pushes the food down through waves of muscle contractions called peristalsis.  The pharynx is where the nasal cavity and the back of the mouth meet in the esophagus.  The epiglottis is the flap of skin in the esophagus that keeps food from going into the trachea.

15. Ch. 3-3 The Stomach  The food that has been moved through the esophagus now lands in the stomach.  The stomachs physical churning of the food is a type of mechanical digestion.  Likewise, the various chemicals that engulf the food are an example of chemical digestion.  Without the thick lining of mucus on the inside of the stomach, the chemicals could digest the stomach itself!

16. Ch. 3-4 Small Intestine  The small intestine is where virtually all chemical digestion and absorption takes place.  The wall of the small intestine is lined with certain folds called villi that aid in absorption.  The small intestine is extremely long, strangely much longer than the large intestine.  Broken down molecules from food are absorbed through the walls of the intestine.

17. Ch. 3-4 Pancreas, Liver, Gallbladder  The liver is the largest and heaviest internal organ. It produces bile, a certain chemical compound that aids in the digestion of fat.  The gallbladder is the smaller organ underneath the liver that stores extra bile until it is needed.  The pancreas secretes special enzymes that aid in digestion. All these organs work together to help the process of digestion move more smoothly.

18. Ch. 3-4 Large Intestine  The large intestines main purpose is to eliminate excess water from undigested materials  Fiber, found in many types of fruits, is an example of one such material.  The large intestine readies these materials for elimination through the excretory system. END