U NIT 14: N UTRITION & D IGESTION C H. 9 & C H. 10 In the first unit we talked about the characteristics of life…. Which one(s) relates to this unit? How do organisms get that energy? How do organisms get food? What do they do to food so that the nutrients can get into their cell(s)? What about multicellular organisms??? How do nutrients get to all of their cells?

N UTRIENTS What are nutrients? complex & simple substances required for life processes What must be done to large molecules (carbs, fats, & proteins) that doesn’t need to be done small molecules (water, vitamins, & minerals)? Why? large molecules need to be digested (broken down) so that they can diffuse through cell membranes Are undigestable materials considered nutrients? Why is water important?

W HAT IS DIGESTION ? What is digestion? breakdown of complex organic molecules into simple molecules polymers  monomers/building blocks Why is this necessary? so molecules can diffuse through cell membranes 2 types of digestion? mechanical (ex. chewing) Why is this necessary? to increase surface area & make chemical digestion faster chemical involves enzymes Organic Biological Macromolecule PolymerMonomer (building blocks) Function Carbohydrates (sugars, starches, cellulose) polysaccharide (such as starch & cellulose) monosaccharide (simple sugars such as glucose) Energy source, energy reserve, plant cell walls Lipids (fats, oils, & waxes) Not applicableFatty acids & Glycerol (Built from 2 types of simpler molecules… NOT monomers.) Energy reserves, cell membrane, hormones, insulation, nerve transmission ProteinPolypeptidesAmino acids (20 different A.A.) Structure, enzymes, transport materials in & out of cells hormones, muscle Nucleic Acids (DNA & RNA) Polynucleotide (Nucleic Acids) Nucleotides (sugar-phosphate backbone & nitrogenous bases) Carries genetic code (“blueprint for organism) & directs protein synthesis

H UMAN NUTRITION & DIGESTION Examples of complex nutrients? proteins fats (lipids) carbohydrates Do complex nutrients require digestion? Why/why not? Yes, b/c too big to diffuse through cell membrane. Examples of simple nutrients? vitamins minerals water Do simple nutrients require digestion? Why/why not? No, b/c small enough to diffuse through cell membrane

H UMAN D IGESTIVE S YSTEM

enzyme (salivary amylase) starch maltose sugar (polysaccharide ) (disaccharide) What type of digestion takes place in the mouth? physical chewing Why do we chew food? increases surface area & speeds up chemical digestion chemical enzymes (starches  sugars) What does saliva do? moistens food contains enzymes Human Digestion

What do the pharynx & esophagus do? connect mouth to stomach How is food moved? peristalsis alternating contraction & relaxation of smooth muscle move food to stomach Human Digestion

What is the epiglottis? flap of tissue that protects trachea (windpipe) while swallowing

peristalsis

What happens in the stomach? physical digestion How? churning chemical digestion of protein into polypeptides begins How? gastric juices made of enzyme (pepsin) & hydrochloric acid storage stomach slowly releases chyme into small intestine Human Digestion What is the function of rugae? Why doesn’t your stomach digest itself??? rugae

accessory organs What does the pancreas do? secretes pancreatic fluid containing enzymes into the small intestine What does the liver do? produces bile breaks fats into tiny drops What does the gall bladder do? stores bile Human Digestion Does food actually go through these accessory organs?

What happens in the small intestine? pancreatic enzymes & bile are added to chyme digestion of starches, proteins, & fats is completed nutrients absorbed thru walls of villi into bloodstream What do villi “add” to the small intestine?/Why is this important? add surface area which increases the efficiency of absorption of nutrients Human Digestion How is structure related to function in the digestive system?

What does the large intestine (colon) do? reabsorbs water & salts forms solid feces Where is feces stored? rectum Which part is used to eliminate feces? anus Human Digestion

Let’s See What You Remember…

Let’s See What You Remember…