STARCH

Introduction:
Starch is a polysaccharide, that is present in plants. Starch is synthesize with photosintesis.
The objectives of this lab experiment is to test the presence of starch in some leaves.
 
Materials:

-Bunsen burner
-Tripod stand
-Wire gauze
-250 cm3 beaker
-Boiling tube
-Forceps
-Test tube holder
-Leaf to be tested
-90% ethanol 
-Iodine or potassium iodine solution.

Objectives:

- Identify the presence of starch in leaves.

- Relate the presence of starch with photosynthesis.

- Identify the presence of starch in some food.

Procedure:

- Remove a green leaf from a plant that has been exposed to sunlight for few hours.

- Half-fill a 250cm3 beaker with water. Heat the water until it boils. Keep the water at boiling point.

- Use the forceps to place the leaf in the boiling water. Boil for 2 minutes.

- Turn off the Bunsen Burner.

- Place boiled leaf in a boiling tube containing 90% ethanol.

- Place the boiling tube in hot water and boil for 10 minutes or until the leaf decolourizes. (It may be necessary to replace the ethanol).

- Gently remove the leaf and wash with a fine trickle of cold tap water.

- Spread the leaf evenly on a white tile.

-Add a few drops of iodine/potassium iodine solution to the leaf and note any observations.

You could observer some starch spots more dark. Lugol stains specifically starch with a dark-blue.

 Questions:

1.Which is the origin of the starch that you can see in the leaf?

The origin is the photosynthesis.

2.Complete the reaction and write the name of this process?

CO₂ + H₂O-->C₆ H₁₂ O₆ + O₂     

3- Explain the significance of boiling the leaf in water. 
It losesthe turgent condition. 
4- Explain the significance of boiling the leaf in ethanol. 
It loses the color, so the chlorophyll dissapears.
5- Explain the significance of rinsing the leaf in water.
Beacuse the lugol isn't soluble with ethanol. 

SECOND PART:

Introduction:
The objectives of this experiment was to identify starch in differents food.

Material:

- Jam

- Hotdog

- Potato

- Iodine

- Knife

-Three watch glass

Procedure:

- Put each food in different watch glass.

- Open the hotdog in the middle and cut an small piece of potato.

- Then put one piece of hotdog, potato and jam in the watch glasses. 

- Use the dropper to put iodine.

- Finaly compare the potato with the rest.

Observations:

In the photo you can see the potatos colour is different of the rest, because the potato have a lot of starch.

 

FEHLING'S TEST: REDUCING SUGARS

Introduction:

Fehling's solution is a chemical test used to differentitate between reducing and non-reducing sugars. This test is based on the reaction of a functional group of sugar molecules with Fehling's reagent. Fehling's have two separate solutions:

Fehling's reagent has to separate solutions: Fehling's A and Fehling's B.

Fehling's A: is a blue aqueous solution of copper (II) sulphate.

Fehling's B: clear and colourless solution of potassium sodium tartrate and sodium hydroxide.

Materials:

-Test tube rack

-10mL Pipet

-Distilled water

-5 test tubes

-5 spatula

-Lactose

-Maltose

-Glucose

-Sucrose

-Starch

-Fehling's A and B solutions

-HCl

Objectives:

- Identify reducing sugars.

- Comprehend redox reactions.

- Understand the relation between structure and reducing ability of some sugars.

Procedure:

1. Take 5 test tubes and label: G, M, S, L, ST

2. Put 2mL of distilled water inside each tube.

3. With different spatulas put a small amount of each sugar. Dissolve the sugar.

4. Add 2mL of Fehling's A solution and then Fehling's B.

5. Place each test-tube in a boiling water bath (250 mL beaker on a hotplate stirrer).

6. Observe what is happening.

Starch Hydrolysis: 

7. Place 2mL of 1% starch in a test tube and add 0,5 mL of 3M HCL. Mix and place this mixture in a boiling water bath for 10 minutes.

8. After 10 minutes, remove the tube from the water bath and let it cool. Neutralize this solution with 1M NaOH and mix well.

9. Transfer 10 drops of this solution to a small test tube.

10. Add 1mL of Fehling's A solution and 1mL of Feghling's B.

11. Heat for a few minutes in a boiling water bath.

12. Record your observations. Compare the results of this test with your results for unhydrolyzed starch in the step 1 of this experiment.

Observations: 

-Lactose: has reducing power

-Maltose: has reducing power

-Glucose: has reducing power

-Sucrose: doesn't have reducing power

-Starch: doesn't have reducing power

SACCHARIDES PROPERTIES

Introduction:
Saccharides are organic molecules consisting of C, H and O atoms. The empirical formula usually is Cn H2n On. Are divided in two groups:
    -Monosaccharides: formed by linear a carbon chain, are the building blocks of oligo and polysaccharides. They have a one functional group: cetone (C=O) or aldehyde (COH). 
    -Oligosaccharides: small polymer containing between 2 and 10 monosaccharides.
    -Polysaccharides: big polymers with more than 10 monosaccharides.

Materials:

-Test tube rack

-10mL Pipet

- 5 spatula

-5 test tubes

-1 dropper

-Distilled water

-Lactose
-Maltose
-Glucose
-Sucrose
-Starch
-Lugol's  iodine

Objectives: 

1- Identify different sugars from its properties.

2- Differentiate monosaccharides and disaccharides.

3- Understand the relation between structure and some proporties.

Procedure:

We started off by testing some physical properties of the saccharides we have in the lab, such as flavour, the structure and color.

To test the flavour we tasted a small part of each saccharide, and we asked ourselves wether it was sweet or sour?

And by obvserving a small amount of each saccharide under magnification we tested the crystal.

Lastly we tested the color of each element, was it creamy, white or transparent?

	GLUCOSE	MALTOSE	SUCROSE		LACTOSE	STARCH
Flavour	sweet	sweet	sweet		no sweet	no sweet
Clystalline	crystaline	no crystaline	crystaline		powder	crystaline
Colour	white	cream	white		white	white
Solubility	soluble	insoluble	soluble		soluble	insoluble
Lugol’s iodine	negative	negative		negative	negative	positive

TO TEST SOLUBILITY:

- Clean and dry 5 test tubes and label them: G, M, L, SU, S

-Pour 5mL of water in each test tube.

-With the help of a spatula, put a small amount of each saccharide inside the labelled test tube and test if they are soluble or insoluble.

- Observe is each saccharide forms a mixture called dissolution or a colloidal suspension.

- Finally, add 2 drops of Lugol's iodine to each test tube and test if the reaction is positive or negative. Lugol's is a solution of elemental iodine (I) and potassium iodine (KI) in water that is ise to test a saccharide. The reaction is positive if iodine reacts by turning from yellow to a purple, dark-blueish colour.

Ph

Introduction:
Ph is a measure of the acidity or basicity of a solution. Solutions with a Ph less than 7 are said to be acidic and solutions with a Ph greater than 7 are basic.

Materials:
-Distilled water               -Vinegar
-Milk                               -Strips (universal indicator paper)
-Wine                              -Ph-meter
-Lemon                           -Acetic Acid
-Tomato                          -Tongs
-Coffe                             -8*100 Ml Beaker                                      
-Carbonated beverage    -2 Clock Glass
-NaOH solution             -1*100 Ml Beaker
-HCl solution                  -5 test tubes
-Soup solution                -Funnel
-Test tube rack               -Graduated Cylinder
-10 Ml Pipet                   -Coca Cola
-Distilled water              -Soy milk

Objetives:
-Measure different Ph values of organic and inorganic solutions.
-Prove different metods of measuring Ph.

Procedure:
-Cut the lemon and tomato.
-Put this in two clock glasses.
-Take a piece of indicator paper and put this in the solution for a least 20 seconds.
-Remove the indicator paper.
-Compare its colour with appropriate colour chart.
-Record your results in a result table in your workssheet for compare with the class.
TABLE:

Lemon-2 acidic
Tomato-4 acidic
Milk-7 neutral
Vinegar-2 acidic
Wine-3 acidic
Coca Cola-2 acidic
Distilled water-7 neutral
NaOH-12 basic
HCl-1 acidic
Soap Solution-8 basic
Soy Milk-7 neutral




-Prepare a test tub rack with 5 test tubes (cleaned with distiller water).
-Mark the tubes with the labels; A, A1, A2, A3 and B.
-Add 10Ml of lemon juice to tubes A and B.
-Take the A tube and put 5Ml of its lemon juice to test tube A1.
-Take the A1 tube and put 2,5 Ml of its lemon juice to tube A2.
-Take the A2 tube and put 1,2 Ml of its lemon juice to tube A3.
-Add distilled water to each test tube until it has the same volume as test tube B (10Ml).
-Calculate the concentration and Ph of each test tube:
      Concentration   Ph
B-       50%             2,7
A1-     25%             2,8
A2-     13%             3,08
A3-     12%             3,08
A-       1%               3,08
The test tube B is the most acidic.

Observations:
Questions;
1.Which of the solutions gave an acid Ph?
Lemon,tomato, vinegar, wine, Coca Cola and HCl.
2.Which of thhe solutions was alkaline?
Soup solution and NaOH.
3.Which of the solution were neutral?
Milk and destilled water
4.How does a Ph of 3 differ from Ph of 4 in terms of H+ concentrations?
The ph3 has nine times more protons than the ph4
5.In the second part of the experiment, you have compared the Ph of the same product in different concentrations. In this case explain:
  a.Which is the dependent variable?
     Is the Ph
  b.Which is the independent variable?
      Is the concentration
  c.Which is the problem that we want to solve?
      Can lemon juice concentration variated the concentration?
  d.Which is the control of the experiment?
      B, because is only lemon and we can compare
6.Which Ph do you think that gastric juices might have? Why? Do you think that intestinal Ph has the same Ph? Why?
     Acid because hace acid cloridric.
7.Which Ph do you think that blood might have? Why?
Blood have 7,2 is neutral.
8.What is acid rain? Which are the consequences in the ecosystems and how is its fornation pattern? Is rain in Barcelona acid or Alkaline?
Is a rain that is unusually acidic, meaning that it have a low pH.
Acid rain is caused by emissions of sulfur dioxide and nitrogen oxide, which react with the water molecules in the atmosphere to produce acids.
Rarely happens in Barcelona, but if this happens is in industrial areas like Forum.

OSMOSIS

Introduction: 

Osmosis is the spontaneous movement of solvent molecules through a semipermeable membrane into a region of higher solute concentration (hypertonic), in the direction that tends to equalize the solute concentrations on the two sides. We did this experiment to understand the osmosi.

Materials:

-Potato

-Knife

-Spatula

-Three watch glass

-Distily water

-Salt

-Pen

Objectives: 

- Know about the osmosis phenomena. 

- Understand the process of osmosis in plasmatic membranes.

Procedure: 

- Take the potato and cut it in three picies

- Put it every picie in a watch glass. 

- Take the spatula and make an small hole in the middle of each picie of potato. 

-The first potato is for control de experiment, in the second we put salt and in the third we put distilled water. 

Observations: 

-The first potato- the potato is dry. 

-The second potato- the potato is with more water. 

-The third potato-  the potato absorbs the water. 

MINERAL SALTS IN ORGANISMS

Introduction: 

In this experiment we will be create the bones and shells more flexibles. 


Materials:
-Some shells

-Bone
-Water
-Acetic Acid
-Tongs
-2x600 Ml Beaker
-Mineral Sals
-Acid Clordric
-Safety goggles
-Gloves

Objectives: 

- Identify mineral salts in organisms.

- Understand the function of inorganic biomolecules in skeletal structures of organisms.

Procedure: 

BONES:

- Examine the flexibility of the bone to compare the result.

- We put the bones inside the beaker.

- We took a beaker and we put: 200ml of water and 200ml of acid acetic or vinegar.

- We cover the beaker to protect the solution with watch glass.

-We need to leave it 24 hores to know what happens to the bone.

SHELLS:

- We took another beaker and put water and calcium carbonate.

- We put inside some shells.

Observations:

BONES:

-The bone is more flexible because it is in contact with the acid and vinagre.
-Lose the ridigity.
SHELLS:

-The shells were floatingn because the shells are less dense than the water.
The reaction is HCL + CaCo3=CO2 + CaCl2

QUESTIONS: 

1. Write the reaction that takes place when the acid acetic reacts with the calcium carbonate?

It formed a single bubble.

2. What is happening the shells are soaking of acetic acid? What are the bubbles you can see?

Bubbles are formed. 

The bubbles 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 is more flexible, and leave it the ridigity. 

Because it is in contact with the acid and vinagre.

4. So, what is the function of the calium carbonate in the skeletal structures?

Rigidity.

5. Increases in carbon dioxide to the atmosphere from the burning fossil 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 affects corals reefs?

The reefs coral will be dissolve because the pH will be reduce of the corals.