Marine Biology Do Now 9 26 18 Directions

Marine Biology Do Now 9 -26 -18 Directions: Take out your Do Now sheet and begin the Do Now. • Explain how polar molecules can dissolve other polar or ionic molecules. You can use the example of H 2 O and Na. Cl (Table Salt). • What is the name of the reagent I used yesterday to test for the presence of simple sugar? • What is the name of the reagent I used yesterday to test for the presence of protein? • What are the four categories of macromolecules? • What is 1 function of carbohydrates? • What is 1 function of proteins? • What is 1 function of lipids? • What is 1 function of nucleic acids? • Building up macromolecules (requires, releases) energy. • Digesting macromolecules (requires, releases) energy.

Marine Biology Do Now 9 -26 -18 (KEY) • • • The water molecules pull the salt apart into sodium and chloride ions. The positively charged sodium ions are surrounded by the negatively charged oxygen atoms and the negatively charged chloride ions are surrounded by the positively charged hydrogen atoms. Benedict’s reagent was used to test for the presence of sugar. Biuret’s reagent was used to test for the presence of protein. Carbohydrates, lipids, proteins and nucleic acids Carbohydrates provide energy to living things. Proteins provide protection, structure, support, speed up reactions in living things. Lipids provide energy to living things. Nucleic acids determine the proteins an organism lakes which determines the traits the organism expresses. Building up macromolecules (requires, releases) energy. requires Digesting macromolecules (requires, releases) energy. releases

Tonight’s Homework • Research 5 ways scientists use DNA.

Engage • Students will watch “Strawberry DNA Extraction” on You. Tube. • Source: https: //www. youtube. com/watch? v=v. PGKv 53 z. SRQ

Explore • Students will read background information on strawberry DNA extraction. • Source: https: //www. scientificamerican. com/article/s quishy-science-extract-dna-from-smashedstrawberries/

Explain – Strawberry DNA Extraction Lab • Background: The long, thick fibers of DNA store the information for the functioning of the chemistry of life. DNA is present in every cell of plants and animals. The DNA found in strawberry cells can be extracted using common, everyday materials. We will use an extraction buffer containing salt, to break up protein chains that bind around the nucleic acids, and dish soap to dissolve the lipid (fat) part of the strawberry cell wall and nuclear membrane. This extraction buffer will help provide us access to the DNA inside the cells.

Extend – Strawberry DNA Extraction Lab • Pre-lab questions: – 1. What do you think the DNA will look like in a strawberry? – 2. Where is DNA found?

Extend – Strawberry DNA Extraction Lab • Procedure: – 1. Place one strawberry in a Ziploc bag. – 2. Smash/grind up the strawberry using your fist and fingers for 3 minutes. Careful not to break the bag!! – 3. Add the provided 30 m. L of extraction buffer (salt and soap solution) to the bag. – 4. Knead/mush the strawberry in the bag again for 3 minute. – 5. Assemble your filtration apparatus (cheesecloth over beaker). – 6. Pour the strawberry slurry (juice) into the filtration apparatus and let it drip directly into your test tube. – 7. Slowly pour cold ethanol into the tube. OBSERVE � – 8. Dip the plastic dropper into the tube where the strawberry extract and ethanol layers come into contact with each other. OBSERVE

Conclusions & Analysis of Strawberry DNA Extraction Lab #1: MATCHING Procedure Function • A. Filter strawberry slurry through cheesecloth • B. Mush strawberry with salty/soapy solution • C. Initial smashing and grinding of strawberry • D. Addition of ethanol to filtered extract • ___ To precipitate DNA from solution • ___ Separate components of the cell • ___ Break open the cells • ___ Break up proteins and dissolve cell membranes

Conclusions & Analysis of Strawberry DNA Extraction Lab #2 - #6 • 2. What did the DNA look like? Relate what you know about the chemical structure of DNA to what you observed today. • 3. Explain what happened in the final step when you added ethanol to your strawberry extract. (Hint: DNA is soluble in water, but not in ethanol) • 4. A person cannot see a single cotton thread 100 feet away, but if you wound thousands of threads together into a rope, it would be visible much further away. Is this statement analogous to our DNA extraction? Explain. • 5. Why is it important for scientists to be able to remove DNA from an organism? List two reasons. • 6. Is there DNA in your food? ____ How do you know?

Extend - Now extract your DNA from your buccal (cheek) cells • Follow the directions on the lab. • After completing the cheek cell DNA extraction, determine which cells (strawberry or human cheek) released more DNA. Why?