Biology Catalyst- Friday, 12/20/13 – PERIOD 3 EMAIL ME YOUR LAB REPORT (email@example.com) p3 Subject. Save File As “LastName.FirstName.StepUpLabReport” during the first 5 minutes of class.
Biology Agenda 12/20/13 • Catalyst • Announcements • Study all topics that have been covered. You will have a unit test on homeostasis next week • Acids, bases, and pH Discussion • Homeostasis Disturbance Project
Disturbing homeostasis – DUE JANUARY 3rd • Assume the role of a healthcare provider (physician, nurse, health educator, etc.) whose job is to educate today’s youth on a cardiovascular, respiratory, or renal disease. Create one of the following to inform today’s youth on the disease, what type of treatment is available, and what lifestyle changes they can adopt to prevent this disease. Know your audience (young folks like yourselves) so figure out a way to catch your peers’ attention! • Brochure • Commercial • Pamphlet • Poster • Other? ( must be approved by teacher)
Your product MUST include • Normal physiology • Pathophysiology • How body responds to disease • Be sure to mention HOW homeostasis is disrupted • Risk Factors • Treatment Options • Prevention Tips • Include visual aids and a works cited page
Evaluation criteria • Creativity (50 points) • Scientific Accuracy (100 points) • Organization and Neatness (50 points) • 4. Includes all required elements (50 points)
GPoints P3: P7: Your class can earn class points if: everyonein class: Comes to class quietly and on time Stays focused and on task during class Leaves classroom neat and organized Students are teaching other students Majority of class participates Follows all classroom expectations and procedures And more…
Objectives 12/19/13 We will be able to • Compare and contrast characteristics of acids and bases • Describe the pH scale • Explain the importance of maintaining acid-base homeostasis
Brainpop video – Period 3 • http://www.brainpop.com/science/matterandchemistry/phscale/ • Pay close attention. Take notes if you’d like.
Acids, Bases, and pH • The separation of water molecules into ions causes solutions to be acidic, basic, or neutral. • The pH scale measures how acidic or basic a solution is. • pH of 7—Neutral: Equal concentrations of H+ and OH- • pH below 7—Acidic: Relatively high concentration of H+ • pH above 7—Basic: Relatively high concentration of OH-
ON ACIDS…An acid is a substance that ionizes in water to give hydrogen ions (H+) Arrehenius Theory
Arrehenius Theory ON BASES…A base is a substance that ionizes in water to give hydroxide ions (OH-)
An example of the reaction of Hydrochloric Acid: HCl + H2O H3O+ + Cl- When the HCl breaks apart the free H+is attracted to the H2O and forms a HYDRONIUM ION
So who is the Arrhenius Acid given: HCl + H2O H3O+ + Cl- HCl Why? Because it produces H+
An example of the reaction of Potassium Hydroxide: KOH + H2O K+ + 2OH- When the KOH breaks apart it forms the HYDROXIDE ION (OH-)
So who is the Arrhenius Base given: KOH + H2O K+ + 2OH- KOH Why? Because it produces OH-
Why care about acids and bases? • Acid Rain – • Changing the pH of lakes and stream waters can affect aquatic life • Damages trees and building • Respiration Rates are regulated by pH of blood
Characteristics of Acids • Taste Sour • Affect indicators (red=acid) • Neutralize Bases • Often produce hydrogen gas • pH between 0 and <7
Examples of Acids • HCl, hydrochloric acid • CH3COOH, acetic acid
Characteristics of Bases • Taste Bitter • Feel Slippery • Neutralize Acids (Antacids) • Affect indicators (base=blue) • pH between >7 and 14 • Dissolve grease (Drano, Windex)
Examples of Acids • HCl • H2SO4 • HNO3 • HF • Juices
Real Life Examples of Bases NaOH, sodium hydroxide CaCO3, calcium carbonate NH4+, ammonia
Ph Lab Overview • Part A • Testing the pH of common household products • Part B • Systematically Increasing/Decreasing the Acidity of a Liquid
PROTOCOL • At this time, carefully read pages 184 – 188. • Summarize the “NEED TO KNOW” Background on Buffers found on page 188.
Pre-lab instructions • 1. IN YOUR LAB NOTEBOOK, create a table that looks like the following:
Pre-lab instructions • 2. Using the graph paper provided, create a graph similar to that on page 186. (Figure 5.9) • Use a ruler if you need to
Pre-lab instructions • 3. Create a table that looks like the one on page 187. (figure 5.10)
Lab comments • Only the sink by my desk will work. BE CAREFUL WHEN TURNING IT ON. • Read the labels VERY carefully.
Lab safety precautions GOGGLES AND GLOVES MUST BE WORN AT ALL TIMES!
This “air-blood barrier” (the respiratory membrane) is where gas exchange occurs • Oxygen diffuses from air in alveolus (singular of alveoli) to blood in capillary • Carbon dioxide diffuses from the blood in the capillary into the air in the alveolus
Microscopic detail of alveoli • Alveoli surrounded by fine elastic fibers • Alveoli interconnect via alveolar pores • Alveolar macrophages – free floating “dust cells” • Note type I and type II cells and joint membrane
Lungs and Pleura Around each lung is a flattened sac of serous membrane called pleura Parietal pleura – outer layer Visceral pleura – directly on lung Pleural cavity – slit-like potential space filled with pleural fluid • Lungs can slide but separation from pleura is resisted (like film between 2 plates of glass) • Lungs cling to thoracic wall and are forced to expand and recoil as volume of thoracic cavity changes during breathing
Neural Control of Ventilation • Reticular formation in medulla • Responsible for basic rate and rhythm • Can be modified by higher centers • Limbic system and hypothalamus, e.g. gasp with certain emotions • Cerebral cortex – conscious control • Chemoreceptors • Central – in the medulla • Peripheral: see next slide • Aortic bodies on the aortic arch • Carotid bodies at the fork of the carotid artery: monitor O2 and CO2 tension in the blood and help regulate respiratory rate and depth The carotid sinus (dilated area near fork) helps regulate blood pressure and can affect the rate (stimulation during carotid massage can slow an abnormally fast heart rate)
Peripheral chemoreceptors regulating respiration • Aortic bodies* • On aorta • Send sensory info to medulla through X (vagus n) • Carotid bodies+ • At fork of common carotid artery • Send info mainly through IX (glossopharyngeal n) + *
Overview: Major functions - Uptake of O2, loss of CO2 Respiration gas exchange pathway Overall gas exchange consists of 4 steps in series: • Ventilation • Diffusion between gas and blood • Circulation • Diffusion between blood and cells
nose mouth pharynx larynx trachea lung right bronchus left bronchus bronchiole alveoli diaphragm
Oxygen binds to the iron atom in hemoglobin that is in the ferrous (Fe2+) form. Each Hb molecule has 4 iron atoms and they bind oxygen cooperatively; i.e., binding of the first increases the affinity of the second, etc.