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.

STARCH

OBJECTIVE: Identify the quantity of starch there is in a frankfurt, in a potato, in the jam and in a leave

MATERIAL:

• 
• 1 Potato
• Jam
• Lugol
• Forceps
• 1 frankfurt
• 1 leave
• A knife
• Four watch glasses
• Wire gauze
• A lab burner
• Ethanol  
• A dropper

PROCEDURE:

Leave

1. Boil the leave with H2O (2 min)
2. Put the leave in a test tub with etanol and boil it again (10 min)       
3. We bring it out from the test tube and we pit it in a watch glass
4. We add lugol on the leave

                       

Food

1. Cut a piece of potato, a piece of frankfurt and a piece of jam
2. Put each one in a different watch glass
3. Add lugol at each one to reveal the starch presence

                   

                                                           
QUESTIONS:

1. Which is the origin of the starch that you can see in the leave? The starch came from the photosyntesis.
2. Explain the significance of boiling the leave in water.The significance is to interrupt the photosyntesis.
3. Explain the significance of boiling the leave in ethanol. We boil the leave in ethanol to extract the clorophill.
4. Explain the significance of rising the leave in water. We rise the leave in water to extract any remains of ethanol.

Lugol / Fehling

OBJECTIVES:

1. Identify different sugars
2. Understand the relation between structures

MATERIAL:

• 10 test tubs
• Beaker
• Spatula
• Bunsen burner
  
• 3 pipets
• Wire brush
• Distilled water
• Fehling A
• Fehling B
• Lugol
• Glucose
• Maltose
• Sucrose
• Lactose
• Starch

PROCEDURE: We put 5 test tubs in a test tube-rack, each one with each glucid, and we do the same with the other five test tubs in another test tube-rack. In one grup we will put Fehling and in the other Lugol.

Lugol: 

1. First put a little bit of each glucid in each test tube
2. Add 5ml of distilled water in each test tub
3. Observe what happens
4. Add 2 drops of Lugol
5. Observe the colour 

1. 
   

Fehling:

1.  Put a little bit of each glucid in each test tube
2. Add 2ml of distilled water
3. Add 2ml of Fehling A and 2ml of Fehling B
4. Put the test tube in a boiling water bath (beaker)
5. Observe the colour

RESULTS:

                     Glucose      Maltose      Sucrose      Lactose      Starch

Sweet            sweet          sweet           sweet         sweet          no sweet

Solubility      soluble        soluble        soluble       soluble        no soluble

Lugol            negative      negative       negative     negative       positive
Fehling         positive       positiva       negative     positive        negative

• In Lugol experiment: The Lugol reacts when in the substance there is starch, so when we do the experiment, only the solution with starch it's positive. The others are negative because don't have starch.

• In Fehling experiment: The Fehling reacts with the aldehydes, not with the ketones. So glucose, maltose, and lactose are positive in this experiments becouse are aldehyds. 

Osmosis

OBJECTIVE:
See what happens when we put NaCl and distilled water in a potato and when we put an egg in a vinegar solution and then in a distilled water solution.

MATERIAL:

• 1 egg
• Vinegar
• 1 potato
• Deistilled water  
• NaCl
• Spatula
• Beaker
• Knife

PROCEDURE:
Egg: This experiment is divided in two days.
1st Day:

1. Weight the egg
   
2. Take a 600mL beaker and put inside the egg
3. Cover the egg with vinegar
4. Once the egg's shell is removed, clean and dry the egg 
5. Weight the egg again and write down the number.
6. Put the egg in another beaker 
7. Cover it with distilled water. 

2nd Day:

1. Left the egg one day in the distilled water. After about a day rinse the egg with water and let it dry.
2. Weight again the egg and write it down.
3. Break the egg

Potato: 

1. Lay out three watch glass.
2. Slice the potato in three parts lengthwise. Each slice must be of 1,5cm thick.
   
3. Place each slice onto a watch glass and make a hole in the middle of each slice. The hole does not have to cross the slice.
4. In the first slice hole, don’t put anything. The second fill it with salt and the third with distilled water.
5. Left this preparation 30 minutes.

RESULTS:
Egg:
At the end of the experiment we saw that the distilled water entered into the egg through the sell. The egg increase his size and his weight and when we broke the egg there was lot of water. This is caused because of osmosis.

Potato: 
In the potato with distilled water, the water started to enter into the potato because the potato was hypotonic in relation to distilled water.
In the potato with NaCl, the water started to go out because the NaCl was Hypertonic in relation to potato.


QUESTIONS:
Egg questions:

1. What is happening when the shells are soaking of acetic acid? The shell is detached from the egg the CO2 is released.  
2. Write the results of the dimensions and weight of the egg before and after immersing it in distiller water. Write and draw a simple diagram of the water direction. Before immersing: 56'7g After immersing: 59'4g 
   

Potato questions:

1. Explain the results of this experiment. In the potato with NaCl, it appeared water and in the potato with distilled water, the quantity of water cut down.
2. Why have we left the first slice without any treatment (salt or distilled water)? For have a control.
3. Which are the dependent and independent variables? The dependent variable is the water that enter or leave into the potato and the independent variable is NaCl and distilled water.

General questions:

1. How can you explain (through osmosis) the ability of plant roots to draw water from the soil? The water has a lot of cohesion and the plants are an isotonic organism, so the roots can draw water from the soil.
3. What will it happen if a saltwater fish is placed in a freshwater (low concentration of salts) 
4. aquarium? The fish will absorb water and it will swell because of osmosis. 
Look the image you have below and explain what is happening to the erythrocytes in each situation. In the hypertonic solution the organism has more water than the solution, that has more salts and minerals, and the water leave the organism and it crease. In the isotonic solution the water that leaves the organism is the same quantity than the water that enter in the organism because the solution and the organism have the same quantity of minerals and salts. Finally in the hypertonic solution the organism has more salt and minerals and the water enter into the organism and it gets bigger.

pH

OBJECTIVES:
Know how much pH there's in a lemon and know how we indentify the pH of a lemon

MATERIAL:

• 4 tests tubes
• Water
• 1 lemon
• Beaker
• Destiller water
• Forceps

PROCEDURE: Put in different tubs this quantity of lemon and water

Tests tubes      H2O     Lemon    pH

       1                 1ml   +   5ml         ?

       2                 2ml   +   4ml         ?

       3                 3ml   +   3ml         ?

       4                 4ml   +   2ml         ?

RESULTS:
All the tubs with different solutions had the same quantity of pH, 3.

Tests tubes      H2O     Lemon    pH

       1                 1ml   +   5ml         3

       2                 2ml   +   4ml         3

       3                 3ml   +   3ml         3

       4                 4ml   +   2ml         3

QUESTIONS:

1. Which is the dependent variable? The dependent variable is the pH.
2. Which is the independent variable? The independent variable is the lemon.
3. Which is the control? The control are the tubs that only contains water ans lemon.
4. Which pH do you think that in blood? And in gastric juice? The pH of the blood is neutral because if it was acid the cells will die. And the pH of gastric juice is acid because it has to dissolve the aliments.

       

Mineral Salts in Organisms

OBJECTIVE:
We want to see how much CaCO3 there is in the bones and in the molusc's shells.

MATERIAL:

• Acid acetic 
• Chicken bones
• Mollusc's shells
• Baker
• Tongs
  

PROCEDURE:
Bones:

1. Carefully clean and cut ad much of the meat away from the chicken thin bone as possible.
2. Examine the flexibility of the bone by trying to bend it with yours fingers.
3. Take a beaker and make and add vinegar.
4. Take the bones and drop them in the vinegar.
5. Leave it 24 hours and see what happens to the bone.
6. Remove the bones from the vinegar with a tong and soak them with water.
7. Write the results in the blog.

Mollusks shells:

1. Take another beaker and make the same vinegar solution.
2. Put inside some shells. 
3. Write the observations in your blog.

RESULTS:
The bones became flexible but not a lot because they have other substances. The mollusks shells became flexibles and someones desintegrated.

QUESTIONS:

1. Write the reaction that takes place when the acid acetic reacts with the calcium carbonate. 
   
   
   
2. What is happening when the shells are soaking of acetic acid? What are the bubbles that you can see? When the shells are soaking of acetic acid or vinegar there's reaction with the CaCO3 and the vinegar. The bubbles I can see are carbon dioxide.
3. What is happening to the bone after some days of soaking it in acetic acid? Why is the bone flexible now? The bone become flexible. Is flexible now because the CaCO3 is disolved and now the bone only have colagen.
4. So, what is the function of the calcium carbonate in the skeletal structures? The function of the calcium carbonate in the skeletal structures is make the structures strong
5. Increases in carbon dioxide to the atmosphere from the burning fossil fuels and deforestation threaten to change the chemistry of the seas. Evidence suggests that this increase in atmospheric carbon dioxide is lowering the pH of the oceans in a process called ocean acidification. How can acidification efects corals reefs? The acidification make the corals lose the CO2

Lab Equipment/Safety Labels

DEFINITIONS

• To protect the eyes: Safety googles 
• For measuring temperature: Thermometer
• For cleaning the inside of a test tube: Wire brush
• For measuring mass: Watch glass
• For removing and holding a hot beaker: Tongs
• To protect the bottom of a beaker or flask from the flame; to support a beaker or flask on a ring clamp: Wire gauze
• For holding a flask, a beaker, or a test tube on a ring stand: Iron ring
• For holding an individual test tube: Test tube holder
• For holding one or more test tubes: Test-tube rack
• For measuring and pouring liquids; NOT for heating or mixing substances: Erlenmeyer flask
• For measuring and pouring liquids; for heating or mixing substances: Beaker 
• To aid in pouring a liquid from a wide mouth container to a small-mouth container; to filter substances when filter paper is used: Funnel
• For heating a small amount of substance: Test tubes
• For measuring length or distance: Metric tape
• For transferring a small amount (drops) of liquid: Dropper
• For plucking or handling small objects: Forceps
• To mix or stir substances; made of glass to resist heat, stains, corrosion: Glass stirring 
• For heating, sterilization, and combustion: Bunsen burner
• For stirring: Spatula or pipet
• For pulling liquid into a pipette: Microipets
• For holding solids while being weighed, oras a cover for beaker: Spatula
• For making up solutions to a known volume: Gas bottle

SAFETY LABELS

1. Substances that made explode under definite conditions. Avoid shock, friction, sparks and heat: 
   
2. Substances that can ignite combustible material or worsen existing fires and thus make fire-fighting more difficuls. Keep away from combustible material:
   
   
   
3. Spontaneously flammable substances. Avoid contact with air. Highly flammable gases and flammable liquids. Keep away from open fires, sources of heat and sparks:
   
   
   
4. Substances that very hazardous to health when breathed, swallowed or in contact with the skin and may even lead to death. Avoid contact with the human body: 
   
   
   
5. Substances that can destroy living tissue as well as equipment. Do not breathe vapours and avoid contact with the skin, eyes and clothing: 
   
6. Symbol that designates substances that may have irritant effects on skin, eyes and respiratory organs. Do not breathe vapours and avoid contact with skin and eyes: 
   
7. Substances that when taken up by the body cause slight damage. Avoid contact with the human body, including inhalation of the vapours: 
   

WHAT WILL YOU USE FOR...?

1. Holding 100mL of water: Beaker
2. Measuring 27mLof líquid: Graduated cylinder
3. Measuring exactly 43mL of an acid: Dropper
4. Massing out 120g of sodium chloride: Buret