L12: DNA EXTRACTION

1. INTRODUCTION

Deoxyribonucleic acid (DNA) is a nucleic acid that encodes the genetic instructions used in the development and functioning of all known living organisms and many viruses. Nucleic acid are biopolymers formed by simple units called nucleotides. Each nucleoide is composed of a nitrogen- containig nucleobase ( G,T,C,A) as well as a monosacharide and a phosphate group.
These nucleoides are joined to one another in a chain by covalent bonds between the sugar of one nucleoide and the phospate of the next. Most DNA molecules consist of two strands coiled around each other to form a doble helix. Hydrogen bonds bind the nitrogenous bases of the two separate strands.
The two strands run iin opposite directions to each other and are therefore anti-patallel. Moreover the bases of the two opposite strands unit according to base pairing: A-T and C-G.
Within cells, DNA is organized into structures called chromosomes.

2. OBJECTIVES

- Study DNA structures.
- Understand the process of extracting DNA from a tissue.

3. MATERIAL

- 1L Erlenmeyer flask
- 100mL beaker
- 10mL graduated cylinder
- Small funnel
- Glass stirring rod
- 10mL Pipet
- Knife
- Safety goggles
- Cheesecloth
- Kiwi
- Pineapple juice
- Distilled water
- 90% Ethanol ice-cold
- 7mL DNA buffer
- 50mL dish soap
- 15g NaCl
- 900mL tap water

4. PROCEDUCE

1. Peel the kiwi and chop it to small pieces. Place the pieces of the kiwi in one 600mL beaker and smash with a fork until it becomes a juice pure.

2. Add 8mL of buffer to the mortar.

3. Mash the kiwi puree carefully for 1 minute without creating many bubbles.

4. Filter the mixture: put the funnel on top of the graduated cylinder. Place the cheesecloth on top of the funnel.

5. Add beaker contain carefully on top of cheesecloth to fill the graduated cylinder. The juice will drain through the cheesecloth but the chucks of kiwi will not pass through in to the graduated cylinder.

6. Add the pineapple juice to the green juice ( you will need about 1mL of pineapple juice to 5mL of the green mixture DNA solution). This step will help us to obtain a purer solution of DNA . Pineapple juice contains an enzyme that breaks down the proteins.

7. Tilt the graduated cylinder and pour in an equal amount of ethanol with an automatic pipet. Put the ethanol through the sides of the graduated cylinder very carefully. You will need about equal volumes of DNA solution to ethanol.

 8. Place the graduated cylinder so that it is eye level. Using the stirring rod, collect DNA at the boundary of the ethanol and kiwi juice; only the stir in the above ethanol layer!

9. The DNA precipitate looks like long, white and thin fibers.

10. Gently remove the stirring rod and examine what the DNA looks like.

5. OBSERVATIONS/ CONCLUSION

We can observe the fibers of DNA.

6. QUESTIONS

1. What did the DNA looks like?

The DNA looks like white  and thin fibers.

2. Why do you mash the DNA? Where it is located inside the cells?

The crush to extract the liquid from the kiwi, the DNA is in the nucleus of cells.

3. DNA is soluble in water, but not in ethanol. What does this fact have to do with our method of extraction?

We can see the DNA in the part of ethanol because, if we touch the water the DNA can dissolve.

L11: PROTEIN AND EVOLUTION

1. INTRODUCTION

Genes are made of DNA and are inherited from parent to offspring. Some DNA sequences code for mRNA wich, in turn, codes for the amino acid squence of proteins, Cytochrome C is a protein involved in using energy in the cell. Cytochrome C is found in most, if not all, known eukaryotes. Over time, random mutacions in the DNA sequence occur. As a result, the amino acid sequence of Cytochrome C also changes. Cells without usuable C are unlikely to survive.

2. OBJECTIVES

To compare the reladness between organisms by examining the amino acid sequence in the protein, Cytochrom C.

3. PROCEDUCE

 The image is from Ignacio, because I can not find my photocopy.

4. CONCLUSION

As far from each other and are more differences further evolutionarily amino acids. Are grouped by groups of animals.

5. QUESTIONS

1. How many Cytochrom C amino acid sequence differences are there between chickens and tukeys?

0.

2. Make a branking tree, or cladrogram for chikens, penguins and turrrkeys?

chicken- penguin: 0
turkey-penguin: 3

3.a Predict the number of Cytochrom C amino acid sequence differences you would expect to see between.

Horse-Zebra: 1-2

Donkey-Zebra:1-2

b) What other information did you use to make this prediction?

If they can repoduce and the offpring is festile.

5. List three other things used to determine how organisms are related to each other.

Comparing the organs, anatomic prove, embrions,,,

6.  Explain why more closely related organisms have more similar Cytochrome C.

Evolutionarily not so long ago parted hence have not so many mutations.

7. Other data, including other genes, suggest that fugi are more closely related to animals than plants. What are some reasons that the Cytochrome C data suggest that fugi, plants, and animals are equally distantly related?

If you have more than 40, suffered a lot of mutations and can not be compared. 

L10: PROTEIN DESNATURALITION I

1. INTRODUCTION

Desnaturation is a process in which proteins or nucleic acids lose the quaternary, tertiary and secondary structure that is present in their native state. Desnaturation is the result of the application of some external stress ( heat and pH change) or base, a concentrated inorganic salt or organic solvent.

If proteins in a living cell are denatured, this results is disruption of cell activity and possibly cell death. Denatured proteins can exhibit a wide range of ring characteristics, from loss of solubility to communal aggregation.
This las effect results from the bonding of the hydrophobic proteins to reduce the total area exposed to water. In very few cases denaturation is reversible and proteins can recuperate their native state when the denaturation is reversible and proteins can recuperate their native state when the denaturing factor is removed. This process is called renaturation.

2. OBJECTIVES

- Study the relation between the structure and the function of proteins,

- Understand how temperature, pH snd salinity affect to the protein structure.

3. MATERIAL

- 2X50 mL beaker
- 4 test tubes
- Test tubes rack
- 10 mL pipet
- Knife
- Glass marking pen
- Potato
- Distilled water
- Hydrogen peroxide
- NaCl
- HCl

3. PROCEDUCE

In this experiment we are going to test the catalase activity in different environment situacions. We are going to measure the rate of enzyme activity under various conditions, such as different pH values and temperatures. We will mesuare catalase activity by observing the oxygen gas bubbles when H2O2 is destroyed. If lots of bubbles are produced, it means the reaction is happening and the catalase enzyme is very active,

-  Prepare 30 mL of H2O2 10% in a beaker ( use a pipet).
-  Prepare 20 mL of HCl 10% in a beaker.
-  Prepare 30 mL of NaCl 50 % in a beaker.
-  Peel a fresh potato tuber and put the tissue.
- Label 5 test tubes (1,2,3,4,5).
- Immerse 10 minutes your piece of potato inside HCl and NaOH beaker, and mashed up the potato.
- Add 5 mLH2O2 10% in each test tube.
- With a glass- marking pen mark the height of the height of the bubbles.
- Compare the results of the 5 test tubes.

4. OBSERVATIONS 

- Independent variable: treatment of each potato.
- Dependent variable: the height of the bubbles.
- Experimental Group(s): the rest.
- Control Groups: treatment of each potato.
- Constants: size, amount of H2O2, time...

5. CONCLUSION

Mashed > Raw > NaCl > HCl > Potato boiled.

6. QUESTIONS

1. How did the temperature of potato affect the activity of catalase?

The enzime X of the catalase.

2. How did the change of the Ph of the potato affect the activity of the catalase?

The pH change for acid the catalase no activity while ppH change for a basic the catalase activity.

3. In wich potato treatment was catalase the most active? Why do you think this was?

The mashed up potato , because when we mashed up the potato break the enzyme X.