Digestive System Quiz PDF

Digestive system quiz 10.1 - 10.2 MACROMOLECULES: LARGE molecules made up of smaller molecules that are linked together. Macromolecules are known as “ESSENTIAL NUTRIENTS,” (must be obtained from our foods). - RAW materials our bodies need to provide energy, to regulate cellular activities and...

Digestive system quiz 10.1 - 10.2 MACROMOLECULES: LARGE molecules made up of smaller molecules that are linked together. Macromolecules are known as “ESSENTIAL NUTRIENTS,” (must be obtained from our foods). - RAW materials our bodies need to provide energy, to regulate cellular activities and to build and repair tissues. - Provide energy and matter that are used to maintain the body’s METABOLISM, which is the SUM total of all the chemical reactions that occur in an organism. FOUR MAJOR CATEGORIES OF MACROMOLECULES 1. CARBOHYDRATES: provide materials to build cell membranes and provide QUICK ENERGY for use by cells. a. MONOSACCHARIDES: ONE simple sugar. Ex. Glucose, fructose. b. DISACCHARIDES: TWO simple sugars. Ex. Lacoste. c. POLYSACCHARIDES: Complex carbs made of MANY linked monosaccharides. Ex. starch, cellulose, glycogen. 2. LIPIDS: STORE energy reserves for later use by cells, cushion and insulate internal organs, and provide MATERIALS to build CELL membranes. Ex. Fats, oils, waxes. 3. PROTEINS: Provide structure + support for blood cells, body tissues & muscles. Aid muscle movements. Provide immunity against infections and transport ions in cell membranes. a. Insulin, hemoglobin, enzymes. 4. NUCLEIC ACIDS: Contain the organism’s genetic information and also DIRECT the organism’s growth. Ex. DNA and RNA HYDROLYSIS: chemical reaction in which WATER breaks apart macromolecules into smaller molecules. Macromolecules must be chemically broken down into smaller functional molecules that can be absorbed by the cells lining in the small intestine. ENZYMES: help break down macromolecules. They act as a CATALYST, increasing the rate of reaction, without being used up. Enzyme names end in “ase” IMPORTANCE OF WATER IN THE BODY: Vital for maintaining body’s fluid balance, where the amount of water lost from the body equals the amount of fluid gained. - Transports dissolved nutrients. - Removes waste from cells. - Lubricates tissues and joints. - Main component of body fluids. - Regulates body temp. - Eliminates waste materials. ANIMALS OBTAINING FOOD 1. FILTER FEEDERS: filter SMALL organisms from sucked water. Ex. tube worms 2. SUBSTRATE FEEDERS: live on/in a food source and eat it as they develop. Ex. earthworm or caterpillar. 3. FLUID FEEDERS: consume nutrient rich fluids from plants. Ex. butterfly 4. BULK FEEDERS: ingest large chunks of food. Ex. humans FOUR STAGES OF FOOD PROCESSING 1. INGESTION: taking in or eating food. 2. DIGESTION: breakdown of food by MECHANICAL or CHEMICAL means into smaller molecules. 3. ABSORPTION: transportation of products of digestion from the digestive system into the CIRCULATORY system, which distributes them to the rest of the body. 4. ELIMINATION: removal of undigested solid waste matter from the body. THE ALIMENTARY CANAL: a long open tube, where food passes through and is processed (starts at the mouth and ends at the anus). DIfferent organs process the food in different ways. 1. MECHANICAL DIGESTION: PHYSICAL breakdown of food from large chunks to small pieces. Ex. by teeth, muscular contractions of tube.  2. CHEMICAL DIGESTION: breakdown of macromolecules into functional units, done by enzymes. Herbivores and omnivores have longer canals. - Plant tissue is much more difficult to digest so a LONGER digestive tract means more time/chances to extract energy and nutrients from a meal. THE HUMAN DIGESTIVE SYSTEM 1. THE MOUTH: both mechanical and chemical digestion. a. Teeth take large chunks of food and grind them into small pieces, exposes more surface area for saliva to act on the food b. SALIVA can be produced by three sets of glands: parotid, sublingual, and submandibular i.CHEMICAL DIGESTION: salvia is full of amylase: enzyme that helps break down a complex carb into simple sugars ii.LUBRICATION: soaks and coats food to facilitate swallowing iii.DISSOLVES water soluble nutrients iv.STIMULATES: taste buds 2. TONGUE AND CHEEKS: helps with mechanical digestion. Flex & force food that squeezes out between the molars back under them for further grinding. a. Tongue helps chewed food form a BOLUS: soft rounded mass of chewed food, and forces it to the back of the throat where it is swallowed. 3. THE ESOPHAGUS: hollow muscular tube that connects the mouth to the stomach. It has glands lining that secrete mucus to further facilitate passage. - ESOPHAGEAL SPHINCTER: end of the esophagus, muscular valve, “DOOR” to the stomach a. The bolus enters the pharynx (throat), which is the shared opening both to the esophagus and trachea. b. The bolus goes through the esophagus, and passes the larynx (opening to the trachea, which is covered by the epiglottis). c. PERISTALSIS: wavelike muscular contractions. 4. THE STOMACH:(secretions with a pH as low as 2) muscular, J-shaped organ. HOLDS FOOD while it undergoes further chemical and mechanical digestion. a. Muscle walls are highly folded, “rugage:” i.Increases surface area for digestion, provides expansion room for large means & are lined with glands that secrete gastric juices. (made up of hyrochloric acid, salts, enyzmes, water, mucus) b. The stomach releases “PEPSIN” to break down proteins into polypeptides. c. 3 layers of muscle, that contract and relax to break up food, & churn it with gastric juice. Which creates CHYME (undergoes both mechanical and chem digestion, therefore it better enables nutrients to be absorbed during digestion) (a thick liquid). d. PYLORIC SPHINCTER: controls flow of material out of the stomach + prevents backflow from the intestines. Bottom end of the stomach. e. Nerves control movement of materials out of the stomach, and causes contractions in the stomach that allow chyme to flow into the S.I. Once enough is released, the chyme is stored into the stomach until more can be released. 5. THE SMALL INTESTINE: where enzymes finish chemical digestion & ABSORPTION (monosaccharides, amino acids (by the blood stream, go to the liver) and glycerol + fatty acids are absorbed by the cells of SI. - Form TRIGLYCERIDES: coated with proteins, enter the bloodstream, then are broken down by lipase enzymes that are absorbed by cells for energy) (substance crosses a cell membrane) begins. a. Walls are HIGHLY folded. Each fold is lined with VILLI: small fingerlike projection; increases SA of intestines. i.Each villi is covered with MICROVILLI: GREATLY increases SA. b. Three main regions: i.THE DUODENUM: Tough, U-shaped with thick walls. Accessory organs act with this to further chemically digest food. +Begins absorbing nutrients. ii.THE JENJUM: most highly folded area. Lots of absorption of nutrients occurs, but still more chemical digestion. iii.THE ILEUM: fewer villi, but is the LONGEST portion. Absorbs nutrients, pushes unabsorbed particles into the large intestine.  6. ACCESSORY ORGANS: not part of the alimentary canal. a. PANCREAS: deposits pancreatic fluid containing protease, carbohydrase, and lipase enzymes into the duodenum to help with digestion. Has high concentration of bases to neutralize acidic chyme. Also releases insulin into the bloodstream, which allows glucose to enter cells. b. LIVER: LARGEST internal organ. Make bile, which is stored in the gallbladder until needed. i.BILE SALTS: essential to digest fats by breaking fat droplets into smaller ones that enzymes can work on. ii.BILE PIGMENTS: don’t help with digestion. Waste from destruction of old red blood cells. c. GALLBLADDER: stores bile produced by liver. When needed, gallbladder releases bile into a duct that leads to the duodenum of the SI. 7. THE LARGE INTESTINE: leftover material enters, also called the “colon.” a. Water is reabsorbed. b. Bacteria continue breakdown of undigested matter & produce vitamins that are absorbed. c. Waste forms feces and is stored in the rectum, when full feces exit from the anus. FACTORS THE AFFECT ENZYME ACTION: temperature and pH affect the rate at which an enzyme functions, since each enzyme functions best at a specific temperature and pH range. - When range is exceeded, the enzymes denature (the chemical bonds that hold enzymes together breakdown), and enzymes distort & no longer function.