ONION / MICROSCOPE

OBJECTIVES:

• Using a microscope
• See the differences between animal and plants cells
• See and onion in a microscope

ONION MATERIAL:                                                                    

• 
• Microscope
• Knife
• Safranina tint
• H2O
• Forceps
• Onion

MICROSCOPE MATERIAL:

• Microscope
• Samples of animal and plants cells

ONION PROCEDURE:

1. Make an epidermis cut at the onion
2. Clean the piece of onion
3. Tint the piece with safranina
4. Clean the piece with H2O
5. Put it in ???

MICROSCOPE PROCEDURE:

1. Put the samples in different microscope and observe the difference of the animal and plants cells

QUESTIONS:

• Parts of a microscope

                                   

• Differences between a microscope and a loupe: The fundamental difference is the increase. A magnifying glass increases what you are looking between 10 and 100 times. At an optical microscope allows to see structures like cells and single-cell parasites or bacteria and fungi.
• How the microscopes of the lab augment? 
• Diferences between an animal and a plant cell. The plant cells have geometrical forms, and they are disposed in an organized way, however, the animal cells have different forms among them.

        

DNA

OBJECTIVE: See the DNA of a banana and a kiwi

MATERIAL:

•                 
• Mortar
• Strainer
• Filter paper
• Spatula
• Beaker
• 100g of banana
• Microscope
• Alcohol
• Pineapple juice
• Funnel
• 1/2 kiwi
• Sodium chloride
• H2O
• Ethanol 96º
• Pestle
• Balance
• Graduated cylinder
• Pipette

PROCEDURE: The same for the banana and the kiwi. I'm going to explain the procedure of the banana.

1. We have to weigh 100g of banana
2. In a mortar we grind the banana up to the point that the banana becames juice
3. In a beaker we put 100mL of H2O, 10 mL of soap and 3g of sodium chloride and add the banana.
4. We strain the mixture with the strainer. We use a spatula to make it easier.   
5. We strain the mixture again with the filter paper and with the funnel in a 200mL graduated cylinder. 
6. With the pipette add 1mL of pineapple juice.
7. Then add 6mL of ethanol 96º. When we put it into the test tub, the ethanol 96º has to touch the side of the test tube.
8. We will see that the DNA separates from the cell. 
9. We catch the DNA with a spatula and we put it in the microscope. We will see the DNA.

               

QUESTIONS:

Com s'aconsegueix alliberar el DNA de les membranes que l'envolten.

S'aconsegueix afegint sabó

Per a què s'utilitza el suc de pinya?
Serveix per trencar les proteïnes anomenades histones

Com aconseguim la precipitació del DNA dispers?

Afegint ethanol 96º, que separa el DNA i això fa que el poguem veure.

MILK

- OBJECTIVE: Watch the properties of the milk
- PROCEDURE:

1. First we take a beaker and inside the beaker we put 200ml of milk and we put the beaker a 40 degrees.

• The density of the milk is 1,03g and with this information we need to calculate which quantity of caseind we need

LLET	PROVA	RESULTAT
PH	Papers de PH	6-7
Proteïnes	Test biuret	+
Midó	Lugol	-
Greixos	Sudan III	+
Glúcids reductors	Fehling	+

Catalasa

OBJECTIVE: Know the functions of catalasa and the quantity
MATERIAL:

• Liver's pieces
• Potato's pieces
• H₂O₂
• Two test tubes
• Four beakers
• Two thermometers
• Knife
• Wire gauze
• Bunsen burner

PROCEDURE:

1. We cut the liver and the potato into pieces. We have to add some H₂O_2. Then we put some pieces of each material in two different beakers. Observe what is happening
2.                      
3. We have to repeat the same but in a closed container. We use a test tube with a cork, this cork has a hole to put a thermometer in it. We write the temperature variation every 30 seconds, during 3 minutes.                                                         
4. We put some pieces of liver and potato together in a beaker with hydrogen peroxide and we boil it using a wire gauze and a bunsen burner. We will see that hydrogen peroxide doesn't poduce bubbles, that happens because catalasa enzymes are not reacting. We have denatured the enzyme and thats because catalasa doesn't react.

                                                  
RESULTS:

As we can see in the board, the liver's temperature goes up and the potato's doesn't.

                                          

Test biuret

OBJECTIVE: Know the quantity of protein of  full-cream, skimmed milk, soy milk, egg white and yolk

MATERIAL: 

• 5 Beaker of 250mL
• 5 Test tubes 
• Test tube rack
• Weighing machine
• NaOH
• CuCo4
• Distilled water
• Pipet 
• Skimmed milk
• Full-cream
• Soy milk
• Egg white
• Yolk
• Spatula
• Electronic balance
• Glass stirring
• Dropper

PROCEDURE: This experiment is divided in two procedures

• Procedure 1

1. We indicate in each beaker the name of the substance that we are going to put on it, and we add 100mL of distilled water
2. We add, in one beaker, 10mL of soy milk, in another beaker 10mL of skimmed milk, in another, 10mL of full-cream, in another, 10mL of yolk and in another 10 mL of egg white
3. We stir the mixture with a glass stirring

                                     

• Procedure 2

1. We indicate in each test tube the name of the substance that we are going to put on it. This substance is going to be the mixtures that we have done in the beakers
2. We add 2mL of the substance of each beaker in one test tube
3. We put 2 mL of Na OH dissolution 20% -> 20 g of NaOH and 80 g of distilled water
4. We add 5 drops of CuCO4 1% dissolution -> 1 g of CuCO4 and 99 g of distilled water

                                        

                                  

RESULTS:

• Final colours:

• Full-cream: blue-4
• Skimmed milk: a mixture of blue and grey-5
• Soy milk: Purple-2
• Yolk: dark purple-1
• Egg white: dark blue-3

The substances are ordered depending of the quantity of proteins. The number 1 is that have more proteins and the number 5 is that have less number of proteins.
                            
                         

Soap

OBJECTIVE: Know how to do soap and produce it

MATERIAL:

• A beaker of 600 mL
• Gloves
• Goggles
• Glass road
• Spatula
• NaOH
• Distiller water
• Oil
• Tests tube
• Bunsen burner
• Clock glass

PROCEDURE: We have made three different experiments to produce soap

First procedure

  Material: 500 mL of oil, 183g of distilled water, 63g of NaOH, 35mL of an essence, a spatula and an      erlenmeyer

 Procedure: 

1. Firstly we have to weight out the necessary quantity of NaOH and then we dissolve it with the distilled water.
2. Secondly we add it in an erlenmeyer and we mixes with oil
3. Finally we add the essence that we want fou our soap.

                                                           

Second procedure

  Material: 50 mL of oil and 20g of NaOH of distilled water

  Procedure: 

1. We make a dissolution of NaOH and water
2. From this mixture we only take 50 mL
3. Then we add the oil and we mix it
4.  Finally we have to heat it. We can also add an essence

                                                           

Third procedure

  Material: 20g of NaOH, 80g of distilled water and 2mL of oil

  Procedure: 

1. We dissolve NaOH with distilled water
2. In a test tube we have put 2mL of that dissolution and 2mL of oil
3. We have made two test tubes like this
4. We can add an essence
5. We hit it in a "bany maria", a water bath

                                                 

QUESTIONS:

1. What is the soap? The soap is a chemical compound that is obtained when one makes react an oily acid with an alkali 
2. Which is the reaction that we have done? The reaction is called saponification
3. What capes we have produced? We have produced two capes. Above soap and below oil and glycerin that didn't react yet.
4. Formulate the reaction of it. 

   

                      

LIPIDS PROPERTIES

OBJECTIVES:

• Know the solubility of lipids
• Identify lipids
• Emulsion and effect of detergent

MATERIAL:

• Test tube rack
• 250mL beaker
• Water
• 6 test tubes
• Cellulose paper
• Dropper
• Scissors
• Glass rod
• Olive oil
• Soap
• Milk with different fat content: Full-cream, semi-skimmed and soy milk
• Petroleum ether
• Ethanol
• Sudan III

PROCEDURE:

Solubility of lipids:

1. Put 3 test tube in a test tube-rack, each one with a different mark
2. Put water in one test tube, ethanol in other test tube and ether in other. 
3. Put 1 drop of oil in each test tube
4. Observe the results 

                                     

Lipids identification:

   Translucent mark:

1. Cut one piece (10x10cm) of cellulose paper
2. Put 1 drop of water in a part of the squared piece. You will see a lucid spot.
3. Put 1 drop of olive oil in an other part of the squared piece of cellulose paper. You will see a translucent spot.  

                                   

   Sudan III dye: Sudan III is a red fat-soluble dye that is utilized in the identification of the presence of      lipids, triglycerides and lipoproteins in liquids.

1. Prepare three test tube: Each one with milk with different fat content (M1, M2, M3) 
2. Add 2 drops of Sudan III and observe the results.

                                                                       

Emulsion and effect of detergent:

1. Take a 250mL beaker and put 100mL of water
2. Add 1mL of olive oil. With a glass rod stir the mixture vigorously and let it satnd for a few minutes
3. Observe what is happening
4. Add 2 drops of soap and stir the mixture again. Let it stand for a few minutes and notice the differences between both mixtures

                                                                   

RESULTS:

Solubility of lipids: 

In the test tube with water, the oil didn't mix with it.
In the test tube with ethanol, the oil is more dense than ethanol
In the test tube with ether, the oil mix with it
Lipids identification:
   Translucent mark:
In the part of the paper with water you will see a lucid spot and in the part of the paper with olive oil you will see a translucent spot.  
  Sudan III dye:

• Semi-skimmed milk: The solution stain soft red
• Full-cream: The solution stain reddish
• Soy juice: The colour doesn't change

Emulsion and effect of detergent:
When in the beaker only there are water and oil, when you try to mix them, they didn't blend but when you put soap in the mixture, the soap capture the oil.

QUESTIONS:

1.  From your observation, which compounds can dissolve lipids? The compound that can dissolve lipids is ethanol.
2. Do the oil and water mix? What can you conclude about the polarity of the oil if you know that water is polar? No, they don't. I can conclude that the polarity of the oil is non-polar and more over water can't dissolve lipids.
3. Why is liquid the olive oil at room temperature? Because has a low melting point 
4. Why does a lipid leave a translucent spot on paper? Because is a fatty acid
5. Which type of milk contains more lipids? Why? Full-cream is fattier than the others so it contains more lipids
6. Did the oil and water mix when you added the soap? Yes, it did.