Digestion Respiration Lab 6 101413 Photosynthesis Respiration Ev
Digestion & Respiration Lab 6 10/14/13
Photosynthesis, Respiration Ev ery thi ng res pir es! Digestion, ! Respiration
Digestion and respiration: • energy – the capacity to do work. All organisms need energy to live and do any activity beyond just living. • digestion –breakdown of food into smaller units that can be absorbed by organism (i. e. glucose). – hydrolysis: (-lysis: to separate) Decomposition of a chemical compound by reaction with water, such as the dissociation of a dissolved salt or the catalytic conversion of starch to simple sugars – digestion is hydrolytic
Digestion: more than food in your belly • Chewing (mastication) – Physical breaking-up of food • Salivary amylase – Enzyme that catalyzes production of simple sugars from starch in our mouths • From there, down the pipe
Respiration – 2 DEFINITIONS! …or at least a 2 part definition… • respiration – exchange of oxygen and carbon dioxide between organism and environment. – Humans: breathing; inhaling (O 2 in) and exhaling (CO 2 out) – Plants: gas exchange through stomata • respiration – nutrients converted into useful energy – Through a series of catabolic reactions, glucose (from digestion) is broken down and energy is released. – In a series of anabolic reactions, the energy is used to synthesize adenosine triphosphate (ATP), the primary source of energy for organisms. Catabolic = break down complex into simple Anabolic = combine simple to form complex
Respiration – aerobic and anaerobic
Today’s Lab has 3 parts: • Part A – Human Respiration • Part B – Bean Seed Respiration • Part C – Salivary Amylase Digestion of Starch Set up Part C first.
Part A – Human Respiration • Fill a test tube with water • Add 2 drops phenol red, swirl to mix Red=basic yellow=acidic • Insert a straw and gently blow (don’t suck) Predictions? think about the p. H scale and this equation… CO 2 + H 2 O → H 2 CO 3 → H+ + HCO 3−
Part B – Bean Seed Respiration • 3 types of seeds: 1. Killed with formaldehyde 2. Living but dormant, from seed packet 3. Germinating • Wear gloves when handling formaldehyde beans and DON’T breath in the fumes!!! Which groups do you predict to be capable of respiration? Which should respire most?
Bean Set-up • 4 test tubes – rinse with distilled water and dry 1. 2. 3. 4. Control (no seed) 1 killed seed (not 3) 1 dormant seed (not 3) 1 germinating seed (not 3) • Place seeds on top of straw piece in test tube • Record color of solution at time 0, 15, 30 minutes from start
Part C - Salivary Amylase Digestion of Starch • In humans, the first digestive reaction of starch produces a disaccharide called maltose. • catalyzed by amylase (an enzyme found in human saliva) starch amylase maltose
Enzymes • • Catalyze (speed up) chemical reactions Almost all reactions need enzymes All are proteins – specific for certain reactions Can be denatured (lose shape) at high temperatures
Observing Digestion… Starch + iodine = blue-black color Maltose + iodine = no color change As starch is digested into maltose the blue-black color will disappear.
Part C Set-up • Before you start read thoroughly!!! This is easy to mess up! • To give you a basis for test (in separate tubes) – 2 drops starch + 1 drop iodine – 2 drops maltose + 1 drop iodine • Collect 5 beakers, 5 eyedroppers, 4 test tubes, rinse with distilled water, dry
Clean ALL Glassware • Please wash and dry all glassware • Clean up area • Leave how you found it!
PART C REPEAT 3 TIMES @ 5 MINUTE INTERVALS – blue/black should disappear with time in beaker C “Saliva” A B + + + iodine + Starch 5 drops D - control + + Starch 5 drops C 5 drops iodine
Quiz next time: 1. Definitions 1. Respiration 1. Aerobic 2. Anaerobic 2. Digestion 3. Enzyme 4. p. H 2. Lab components 1. What happened in part A? Why? 2. What Happened in part B? Why? 3. What happened in part C? Why?
- Slides: 17