2 Nutrients…substances in food that provide energy and materials for cell development, growth, and repair.
3 Classes of Nutrient - Organic Carbohydrates: main source of energyProteins: used for growth. Fats: provide energy (stored)helps body absorb vitaminsVitamins: organic nutrients that help your body to use other nutrients.
4 Classes of Nutrients - Inorganic Minerals: Inorganic nutrients that regulate many chemical reactionsWater: Enables chemical reactions to take place in your cells.
5 Enzymes - Review speed up the rate of chemical reactions They do this without being changed or used up.speed up reactions by reducing amount of energy necessary for a chemical change to begin.
6 Digestive EnzymesAMYLASE secreted in the mouth; breaks down carbohydrates (starches).PEPSIN, found in the stomach, breaks down proteins.Lipase made in pancreas; breaks down fats
7 Additional Chemical Digestives Gastric Juice – found in stomach; very acidic; (3 million times more acidic than your bloodstream) a combination of HCL and Pepsin; breaks proteinsBile – made in liver; first process in breaking fats.
8 Digestion ProcessesChemical: chemicals in the body break large molecules into smaller onesMechanical: physical, using teeth or muscle to help break food down
9 The Alimentary Canal Mouth - chemical digestion glands in mouth produce saliva, which contains amylase, which breaks down starch
10 Mouth Mechanical Digestion: Teeth and tongue break food into smaller pieces
11 Digestive System Esophagus: muscular tube connects throat to stomach. Moves food down by squeezing (peristalsis)
12 Peristalsis Rhythmic contraction of esophagus to move food to stomach.
13 Your Digestive System Stomach: muscular bag Chemical Digestion: pepsin; gastric acidMechanical Digestion: stomach contractions; food stays here ~2-6 hours,End Product:chyme: afood sludge
14 Digestive System Liver: produces bile; stored in gallbladder. Bile breaks up large particles of fats into smaller particles.
15 Some of Liver’s Jobs filters the blood coming from the digestive tract detoxifies chemicals and metabolizes drugs.secretes bile (breaks down fats)makes proteins important for blood clotting
16 Your Digestive SystemGall Bladder: small sac that stores bile produced by liver (breaks down fats)
17 Your Digestive System Pancreas: produces substances that stop the action of stomach acidproduces lipase which breaks fats
18 Pancreas’ Other Jobsexcretes enzymes to break down the proteins, lipids, carbohydrates, and nucleic acids in food.as an endocrine gland, secretes the hormones insulin and glucagon to control blood sugar levels throughout the day.
19 Digestive SystemSmall Intestine: digestive juices from liver and pancreas are addedvilli increase surface area for absorption of nutritents from chyme
21 Small Intestinesabsorbs about 90% of the nutrients from the food we eat.only 1 inch in diameter, making it less than half the diameter of the large intestine.
22 3 Parts of Small Intestine - FYI duodenumconnects to the pyloric sphincter of the stomach.Partially digested food, or chyme, from the stomach is mixed with bile from the liver and pancreatic juice from the pancreas to complete its digestion in the duodenum.
23 3 Parts of Small Intestine - FYI The jejunum is the middle section; primary site of nutrient absorptionThe ileum is the final section and completes the absorption of nutrients that were missed in the jejunum.
24 Digestive SystemLarge Intestine: absorbs (removes) water from undigested food;unabsorbed materials become more solid (waste - poop).
25 Your Digestive SystemRectum: where muscles control the release of wastes from the body