To prepare a temporary mount of onion cells. (LAB REPORT)

Aim: - To prepare a temporary mount of onion cells.

Materials Required:- Onion, Knife ,Forceps ,Blade ,Slides ,Watch glass ,coverslip ,brush, compound microscope, blotting paper, a clean piece of cloth,
Iodine solution, Safranine, Glycerine and water.

Introduction:- Onion is a plant that belongs to the genus allium.  Its binomial term is allium cape.  Commonly known as garden onion, the rounded edible bulb of the onion plant cultivated globally develops underground. The onion plant has hollow leaves and it should not be mistaken with tuber, which it is not.



Procedure:-

• Take a piece of onion scale and bend it towards the concave side until it breaks into two. When it breaks, it will be notice that a thin membranous structure still connecting the two bits. This membranous structure is called onion peel or epidermis.
• Carefully tear off one of the bits from the epidermis hold the freed epidermis with a forceps and peel it from the other bit.
• Take some water in a watch glass and put the epidermis in it Make certain that it is not folded or rolled.
• Add 1-2 drops of Iodine solution or Safranine solution.
• After about 2-3 minutes take the peel and wash in acid water if Iodine solution is used or in plain water if Safranine is used.
• Take a clean glass slide and put a drop of glycerine almost in the middle of the slide.
• Place the stained piece of the peel in the glycerine and put a cover slip on it.
• Soak the overflowing fluid from the corners of the coverslip with the help of the blotting paper and clean the side.
• Observe the wet mount under the low power of the microscope and then under high power

Observations:-

{Under Low power of the microscope} 

1. The rectangular cells of onion epidermis are seen. The regularly arranged components like cells have clear outline. In this case, the outlines are formed by rigid walls known as Cell Wall.
2. A deeply coloured, round body is seen in side every cell. This is known as Nucleus.

{Under the high power of Microscope}

1. Nucleus with Nucleolus is clearly visible.
2. A thin layer of less deeply coloured substance along the inner surface of cell wall is seen. It is called Cytoplasm.
3. The central part of the cell, interior to the cytoplasm takes very little stain, this portion is known as vacuole.

Energy in food:- M3 ( LAB REPORT )

Aim: To determine energy content of food samples provided.

Introduction: Food is the most important way in which energy is taken into the body. It’s the energy in food that sustains us, and the effect of food energy on our body is the basis for the dietary practice. Carbohydrates, fibre, fats, proteins, organic acids, polios, and ethanol all release energy during respiration — this is often called 'food energy'. When nutrients react with oxygen in the cells of living things energy is released. A small amount of energy is available through anaerobic respiration. Fats and ethanol have the greatest amount of food energy per mass, 9 and 7 kcal/g (38 and 30 kJ/g) respectively. Proteins and most carbohydrates have about 4 kcal/g (17 kJ/g).

Requirements: clamp stand, Matches, Burner, Two food samples (Groundnut, Almond) , Needle to hold the food samples, water, Gas burner,  electronic balance, Thermometer.

Procedure: 1) Take water in the test tub and weigh it and take the temperature.

2) Then take the weight of test tub with water put it on the stand.

3) Then take the food samples and burn it till it doesn’t start to burn by its own.

4) Then take it down of the test tube and tell it does not distinguish.

5) Then again start to count the maximum temperature of water, weight of burnt food sample and

6) Record the observations.

Observation: When the food sample burn then it would start burning by its own and it was showing the energy and oil that was there in the food. In food samples of Almond and Groundnut the Almond burned for more time.

Data table
Measurements	Sample 1	Sample 2
Food used	Groundnut	Almont
Mass of measuring   cylinder	29.3	29.3
Mass of test tube plus water	39.8	39.8
Minimum temperature of water	30	30
Maximum temperature of water	69	70
Initial mass of food	0.7	1.0
Final mass of food	0.2	0.6

Floating Leaf Disk Assay :- ( LAB REPORT )

Aim: Investigation of Photosynthesis using the Floating Leaf Disk Assay.

Introduction: Leaf disks float, normally.  When the air spaces are infiltrated with solution the overall density of the leaf disk increases and the disk sinks.  The infiltration solution includes a small amount of Sodium bicarbonate.  Bicarbonate ion serves as the carbon source for photosynthesis.  As photosynthesis proceeds oxygen is released into the interior of the leaf which changes the buoyancy--causing the disks to rise.  Since cellular respiration is taking place at the same time, consuming oxygen, the rate that the disks raise is an indirect measurement of the net rate of photosynthesis. The standard procedures such as counting oxygen bubbles generated by an elodea stem. Over the years, these have found the floating leaf disk assay technique to be reliable and understandable.

Requirements: Sodium bicarbonate, Liquid soap hand wash, Plastic syringe, Punching machine, Plastic cup, Leafs, Timer, Light bulb.

Procedure:

1. Obtain enough sodium bicarbonate solution for each trial. You will be using a 0.2% solution, which has a trace amount of liquid soap in it.300 ml of bicarbonate solution for each trial. The bicarbonate serves as an alternate dissolved source of carbon dioxide for photosynthesis. The soap wets the hydrophobic surface of the leaf allowing the solution to be drawn into the leaf.
2. Utilizing a Punching machine cut 10 leaf disks for each trial. Avoid major veins.
3. Infiltrate the leaf disks with sodium bicarbonate solution until only a small volume of air and leaf disk remain in the barrel (< 10%).
4. Pull a small volume (~ 5 mL) of sodium bicarbonate solution into the syringe. Tap the syringe to suspend the leaf disks in the solution. Holding a finger over the syringe opening side, draw back on the plunger (~ 1 mL) to create a vacuum.
5. Hold this vacuum for about 10 seconds. While holding the vacuum, swirl the leaf disks to suspend them in the solution. Let’s off the vacuum. The bicarbonate solution will infiltrate the air spaces in the leaf causing the disks to sink.
6. Pour the disks and solution into a beaker. Add bicarbonate solution to a depth of about 20ml. Use the same depth for each trial. Shallower depths work just as well.
7. This one will be placed under a light source.
8. Place your first sample away for the supplemental light source and your second sample under the light source. Start timing as soon as your sample is set up. At the end of each minute, record the number of floating disks. Then swirl the disks to dislodge any that are stuck against the sides of the cups. Continue until all of the disks are floating.

Observation: noted all the things that were Observed and come to know that the disks come fast up in dark area.

Data table
Minutes	Disks(light)	Disks(Dark)
1	0	2
2	0	4
3	0	4
4	1	6
5	3	5
6	3	6
7	3	6
8	5	8
9	7	9
10	8	10
11	10	-

The Effect of Temperature on the Cell Membrane of Beetroot Cells :- ( LAB REPORT )

Aim: To investigate whether temperature will damage and denature the plasma cell surface membrane of beetroot cells.

Introduction: The purpose of a cell membrane is to control the transport of substances moving into and out of a cell. The membrane is an extremely thin layer (8 to 10 manometers (nm)) thick, which is partially permeable. It consists mostly of lipids and proteins. The lipids found in cell membranes belong to a class known as triglycerides, so called because they have one molecule of glycerol chemically linked to three molecules of fatty acids. In the cells of a beetroot plant, a substance called anthocyanin is contained within the plasma membrane. It is anthocyanin, which gives the beetroot its characteristic blue/purple colour. If a cell is damaged in a beetroot plant and the membrane is broken, the anthocyanin 'bleeds' from the cells...

Requirements: Beetroot, thermometer, cork borer, white tile, scalpel, 2 x 250ml beakers, glass-marking pen, graduated pipette (10ml), 3 x test tubes and rack, mounted needle, stopwatch, Bunsen burner, tripod and gauze, colorimeter with blue filter, Ruler, blade, cuvette

Procedure: 

1. Using the cork borer cut 3 or 4 cylinders from your beetroots. Place these cylinders on the tile and use a scalpel to cut them into discs about 3 mm thick. You will need 12 discs
2. Put the discs in beaker and wash them for at least 5 minutes.
3. Label the 2 test tube, each with 40 or 70 using the graduated pipette place 10ml tab water in each one.
4. When the beetroot discs have been washed, put 6 of them on a mounted needle with a space between the discs.
5. Heat the water bath to 40⁰ C impale 6 discs, give them a water bath for exactly a minute and then put it in the labelled 40.
6. Repeat the procedure for temperature 70⁰C and leave it for 20 minutes
7. Fill a clean cuvette with tap water these will be blank.
8. Select the blue filter on the colorimeter, and use the blank to zero the colorimeter.
9. Shake the test tube of pigment and put in in cuvette and then take the reading from the colorimeter.

Observation:

The Colorimeter Readings are:

Temperature	Colorimeter Readings
40o C	0.25
70oC	1.42

Plant Pigment Chromatography:- M3 ( LAB REPORT )

Plant Pigment Chromatography

Aim: To separate pigments from leaves of a green plant using paper chromatography and to determine the wavelength at which energy is absorbed by the individual pigments using spectrophotometry.

Introduction: All cells must constantly consume fuel molecules to maintain themselves, grow, and reproduce. Fuel molecules such as glucose constitute an immediate source of energy for biological work that can be released by catabolic cell processes. However it is necessary that life on earth have a constant source of energy that can be harvested and used to generate complex fuel molecules from simple starting materials. The ultimate energy source upon which all life forms depend is visible light from the sun. There are four different pigment groups present in leaves of photosynthesizing plants. Studies indicate that only the chlorophyll IS involved in the actual absorption of light energy and later conversion to chemical energy of living cells. The other pigments also absorb light energy, but it is transferred to the chlorophyll for conversion to chemical energy.

Requirements: 2 or 3 fresh spinach leaves, wooden ruler, 600 mL beaker, plastic wrap, chromatography paper or filter paper, pencil, coin, 50 mL graduated cylinder, test tubes, scissors, stapler, goggles, cork stopper.

Procedure:

1.  Obtain a 50 ml graduated cylinder with 5ml of solvent in the bottom
   Cut a piece of filter paper or chromatography paper and the edges must be
   Straight that it should reach to the solvent
2. With a pencil lightly make a line 2 cm from the bottom edge of the paper.
3. Select large dark green spinach leaves.
4. Place a leaf over the pencil line leaving on each end to align the ruler.
5. Place the widest side of a wooden ruler (without metal edge) over the leaf so that it covers the pencil line on either end.
6. Using a coin, press down firmly and roll along the ruler edge several times to form a definite green line.
7. Allow the green line to dry
8. Move leaf down and repeat several times until the pencil line is covered completely with a narrow green band. Be careful not to smear this green line.  
9. Staple top and bottom to form a cylinder.
10. Place paper cylinder in beaker with the green band down.
11. The solvent should not touch the green line.
12. Cover the beaker tightly with a piece of plastic wrap being careful not to slosh solvent.
13. Allow to stand undisturbed for 5 minutes.
14. After five minutes lift up corner of wrap and reseal. This will reduce the vapour pressure inside the beaker.
15. Observe the solvent movement and band separation.
16. When the solvent front is within 1 cm of the upper edge of the paper, remove the cylinder from the beaker. Mark the edge of the solvent front with a pencil.
17. Measure distance from the first pencil line to the solvent front. Then measure the distance from the pencil line to the highest point of each colour band and the original pencil line band. Record your results.

Observation:

DATA TABLE
Band No.	Distance Moved (mm)	Band Colour
1	12 mm	olive green
2	21 mm	bright green
3	27 mm	bright yellow
4	53 mm	yellow-orange
Solvent front moved 53 mm