RESUMEN DE LA PELICULA CONTAGIO

Biology Onion Lab

1. Why do we have to chop up the onions?

a. Because it breaks the plant’s cell walls with the intention of allows the cytoplasm to become manifest.

2. What is the purpose of the grinding?

a. Grinding assist to keep on the physical breakdown of the tough cell wall.

3. What does the detergent do in this experiment?

a. The detergent breaks the fats in the phospholipids BIlayers of the cell membrane and nuclear membrane. That way the nuclear material is released from the cell and the chromosomes that contain DNA.

4. Why do we have to filter the mixture? What do we use for filtering?

a. We filter the mixture in order to collect the liquid rich in DNA and to take apart it from the big pieces and the other tissues of the onion.

5. Why can not we shake the mixture? When is it important to not shake the mixture?

a. Because it can cut of the DNA strands.

6. What are enzymes? Why do we use them here?

a. Enzymes are proteins that are involved in all metabolic reactions and accelerating them to form molecules. Enzymes break down the histone proteins that way the DNA is released.

7. What does the heat do/ the ice bath?

a. Heats increase the speed of chemical response. Cooling slow the action of the enzymes prior the DNA is destroyed.

8. What does the ethanol do?

a. Ethanol forms a separate layer on top. It helps to precipitate the process.

9. Why use a stick to gather DNA?

a. Because is long and it wraps around it.

10. On the back Draw a diagram of DNA. Show and label the nitrogenous base pairing, sugar, phosphate, hydrogen bonds. Use your textbook for help necessary.

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