What s the big deal with antibacterial soap? An inquiry lab on adaptation

Transcription

1 What s the big deal with antibacterial soap? An inquiry lab on adaptation

2 Did you know? There is some evidence that triclosan, triclocarban and the other chemicals can disrupt hormone cycles and cause muscle weakness. Consumers don't need to use antibacterial soaps, and some of them may even be dangerous Food and Drug Administration.

3 In September of 2016FDA Bans 19 Chemicals Used In Antibacterial Soaps Cloflucarban Fluorosalan Hexachlorophene Hexylresorcinol Iodine complex (ammonium ether sulfate and polyoxyethylene sorbitan monolaurate) Iodine complex (phosphate ester of alkylaryloxy polyethylene glycol) Nonylphenoxypoly (ethyleneoxy) ethanoliodine Poloxamer-iodine complex Povidone-iodine 5 to 10 percent Undecoylium chloride iodine complex Methylbenzethonium chloride Phenol (greater than 1.5 percent) Phenol (less than 1.5 percent) 16 Secondary amyltricresols Sodium oxychlorosene Tribromsalan Triclocarban Triclosan Triple dye

4 Data the cornerstone of science! o There s no data demonstrating that over the counter antibacterial soaps are better at preventing illness than washing with plain soap and water - the FDA. o Antibacterial soaps are no more effective than regular soap and water for killing disease-causing germs, according to the CDC. Regular soap tends to be less expensive than antibacterial soap and hand sanitizers. Regular soap won't kill healthy bacteria on the skin's surface. Jul 8, 2014 o So why do so many people (including you), use them? LET S DISCUSS!

5 o The FDA has banned these chemical and ordered the industry to change what ingredients go into their products. o It is also part of a boarder effort to encourage consumers to use regular soap and water. o But why? Where we are now o Because the manufacturers haven t proven that those ingredients are safe for daily use over a long period of time. Also, manufacturers haven t shown that these ingredients are any more effective o What is the harm in these chemicals? o Many of these chemicals can cause health issues such as interrupting hormones cycles and increasing resistance. laboratory studies have raised the possibility that triclosan (also used as a pesticide) contributes to making bacteria resistant to antibiotics. Some data shows this resistance may have a significant impact on the effectiveness of medical treatments, such as antibiotics. o Antibacterials may also kill bacteria that actually are helpful to the body because they keep other troublesome bugs in check, experts say.

6 Good bacteria??? o So what about those claims that products kill 99.9% of the bacteria. Isn t that a good thing? o What about that 0.1% o Well what happens to the bacteria that survive the antibacteria soap or sanitizer? o Thoughts ---- Questions? o Write your prediction in the Part A section of your page.

7 That 0.1% o The bacteria that survive are resistant to the bacterial killing chemicals. o How? Mutation? They then pass on these genes to the next generation o Those offspring become almost impossible to kill and what if they are harmful?

8 Fill in on your lab sheet 1.A population is a group of the same kinds of organisms living in the same area. 2.In any population, there is variation in traits among the organisms due to mutation 3. A mutation is a permanent change in the DNA sequence of a gene.

9 4.Some traits help an organism survive and some do not help survival. Some traits, like being left or right-handed, have no effect on survival. The environment determines which traits are favorable. 5. Selective pressure is something that changes the ability of an organism to survive in a particular environment. A selective pressure can be something that is living or something that is not living.

10 6. Organisms with favorable traits survive. We call the favorable trait an adaptive advantage because it helps the organism survive. Organisms with an adaptive advantage (favorable traits) pass the genes for those traits on to their offspring. By this mechanism, over time, more and more organisms in a population have the favorable traits. 7. We say the population has adapted to the environment.

11 8.The marshmallows and Skittles represent bacteria. Most of the bacteria (marshmallows) are the same (clones) due to asexual reproduction. They have a shell, are white, and are cylindrical in shape. soft 9.Some bacteria (the Skittles) are not like the other clones. They represent bacteria that had three mutations resulting in three different traits (colorful, hard shell, and disc shaped).

12 10. The toothpick represents antibacterial hand soap. When you use the toothpick to catch the bacteria (marshmallows and Skittles), it is like bacteria being destroyed by the chemicals in the hand soap.

13 Part C Modeling Natural Selection We will be doing a demonstration activity to show what can happen to a population of bacteria that is not killed by antibacterial soap. Expectations: Follow the steps exactly as written. Record all data Do not eat or taste the lab supplies! You will get a treat to eat while you do your post-lab questions.

14 Bacterial Reproduction Fission:

15 What to do now: o Gather materials as instructed o Read through the written procedure o Fill in the data chart o Answer all of the questions at the end of the lab o Choose one debatable question to respond to as your final step o Double check that you have completed every thing before turning in the lab pages!