Fun facts! brief intro on Photosynthesis!

http://www.youtube.com/watch?v=mpPwmvtDjWw&feature=related

http://www.youtube.com/watch?v=1gLa5EWn9OI&feature=channel

(A BETTER UNDERSTANDING OF HOW LIGHT ENERGY IS CAPTURED BY CHLOROPHYLL)
http://www.youtube.com/watch?v=1wtzfheLvZc&feature=related

credits: youtube.com

Hmm, what are the differences between Respiration and Photosynthesis then?

Pics taken from Google. Info from group.

Comparing between photosynthesis and respiration

Photosynthesis	Respiration
Requires sunlight	Does not need sunlight
Occurs in cells with chlorophyll	Occurs in all living cells
Uses water	Gives off water
Uses carbon dioxide	Releases carbon dioxide
Gets energy from sun	Releases energy from sugar
Makes sugar	Breaks down sugar
Releases oxygen	Uses oxygen

So what happens after Photosynthesis?

The product of Photosynthesis is GLUCOSE.

Glucose can be :

- Used immediately by the leaf cell for respiration to provide energy

- Converted to starch for storage within the leaf

-Converted to sucrose for transport to other parts of plant for example the roots and flower

- Combined with nitrates in the leaf to form amino acids thus allowing the plants to build proteins in order to grow.

                                            Starch stored in cells.





Pics taken from google. Info from group.

Fun facts on Photosynthesis(; TO DO EXPERIMENTS!

WHAT IS CHLOROPHYLL??!!??
As you know, chlorophyll is the green pigment located in thylakoid discs which is contained in chloroplast.This captures the light energy, combines it with carbon dioxide and water and turns it into glucose. But what and how does it contain?

Materials you would need:

-Chromatography paper

-A Pencil

-A leaf (Prefably Dark Green)

-A cork

-A test tube

-Water

-Aluminum foil

- Solvent - Ethanol, Isopropanol, Acetone, Hexan

1.) Firstly, boil water and pour it into a cup. Leave the leaf for about 5 minutes.Dry them.

Boiling water kills the cells and destroys enzymes which can promote chlorophyll degradation. It also breaks chloroplasts which makes chlorophyll extraction easier. 

2.) Cut the veins and grind the rest up till it is consistent and able to flow freely.Spread it on an aluminum foil evenly and bake in the oven at 40 degree Celsius.

3.)Grind it in a mortar till it is of a uniform yellowish green colour. Put it in a test tube and add a few ml of solvent, close the lid and shake it.

4.) There should be emerald-green slightly opalescent liquid on top of dark green powder (which will sink to the bottom of the test tube)Right now it's diluted and solution contaminated with fine debris from the broken cells. Remains of chloroplasts and other cell components are floating in liquid making it slightly foggy. 

To wrap this nicely...

we do SEDIMENTATION OF LEAF CELL DEBRIS!:D

-leave the solution to sit after 10minutes and let the powder sit, pour the liquid out EXTREMELY carefully.

-Pour the top 90% into a third test tube. Leave it in a well ventilated place for a few days and check it from time to time. You would be able to see the different colours and layers in it 

AND YOU'RE DONE!(:

AND YOU ARE DONE!!!!:D

Leaf Structure In Relation to PHOTOSYNTHESIS!

LEAF STRUCTURE In Relation to PHOTSYNTHESIS!!!

The leaf has several layers of cells:

1.     The topmost layer is a waxy cuticle covering the upper epidermis.

2.     The palisade mesophyll layer lies below the upper epidermis.

3.     The spongy mesophyll layer lies below the palisade mesophyll layer.

4.     The vascular bundles, which consist of the xylem and phloem are dispersed throughout the leaf.

5.     The lower epidermis is the last layer in the leaf . Stomata are usually present on the lower epidermis. 

 

Why is the leaf so thin?                    ---large surface area to volume ratio making it ideal
                                                                for absorption and diffusion

                                                           --- Large surface area allows more sunlight
                                                                to be absorbed 

                                                           ---Thin leaf- mesophyll cells closer to surface,
                                                               thus reduce diffusion distance of carbon dioxide

                                                               from surroundings to palisade mesophyll cells.

                                                             

 Structure                     Function

                                                       

1.Waxy Cuticle                         --Covers the whole leaf to protect the underlying cells.

                                               --Transparent to allow light to enter leaf for 
                                                  Photosynthesis.

                                               -- Prevents leaf from excessive water loss because it 
                                                 is impermeable to water.

2.Upper Epidermis                    --Only one cell layer thick 

                                               --Has No Chloroplasts

                                               -- Allows  sunlight to reach mesophyll cells containing  
                                                  chloroplast so that these photosynthesizing cells can  
                                                  photosynthesize.

                                               --Are tightly linked to each other to provide plant with 
                                                  mechanical strength and protection.

                                               -- None/very few Stomata because if gaseous exchange 
                                                   takes place, the guard cells will open and water will be
                                                   lost and made worse by the heat from the sun so if
                                                   stomata is found here, there will be direct heat from 
                                                   sunlight and excessive water loss.
                                                --However, desert plants with high surrounding
                                                  surrounding temperatures have sunken stomata
                                                  while aquatic plants have stomata on the upper
                                                  epidermis cause their lower epidermis is
                                                  in contact with water.

3.Palisade Mesophyll cells          -- Lying below the waxy cuticle

                                               --Closely packed thus allowing more cells and
                                                 more chloroplasts nearer surface for more light to be   
                                                captured.

                                               -- Contains most chloroplasts as it is an actively 
                                                    photosynthesizing cell.
                                             --  Produce Glucose and directs it to Spongy Mesophyll for 
                                                  storage

                                             --Small intercellular spaces between each other for gaseous
                                                exchange to occur.

4.Spongy Mesophyll                    -- Less chloroplasts and bigger intercellular spaces
                                                  to facilitate gaseous exchange and less chloroplasts 
                                                  to maximize storage of starch.

                                                -- For Storage of Carbohydrates produced from 
                                                   Photosynthesis like starch
                                               --Dissolved carbohydrates eg. sucrose, diffuse into 
                                                 phloem to be transported to rest of the plant.

5.Vascular tissues                        --Consists of xylem and phloem vessels.

                                                 --Xylem is at top of Phloem.They are near cells that are 
                                                   actively photosynthesizing because water can be      
                                                   transported to palisade mesophyll for photosynthesis.
                                                 --Phloem nearer to the spongy mesophyll as they 
                                                   transport sugars from the mesophyll cells to rest of
                                                  plant.

                                                --Both xylem and Phloem are vascular tissues situated in
                                                   leaf vein where fibres like collenchyma support it to
                                                  make leaf flat to maximize Photosynthesis.


                                                       
6.Lower Epidermis                    -- Guard cells that form stomata are found here.

                                              --  Stomata allows gaseous exchange to occur.
                                              --Gaseous exchange is the intake of carbon dioxide and 
                                                  the release of oxygen for Photosynthesis while 
                                                  respiration requires oxygen & releases carbon dioxide.

                                               --Guard cells control water balance by controlling the
                                                 amount of water loss through diffusion of water vapour
                                                from plant.

                                                --Guard cells are specialized epidermal cells. 

6.Stomata                         ---Guard cells control the opening and closing of the stoma, the
                                            pore where gaseous exchange takes place.

                                       ---- When the plant is photosynthesizing, the stomata will 
                                             buckle to open because of the high concentration of 
                                            sugar inside compared to outside environment thus the 
                                            thinner wall of the guard cell expands causing cell to buckle 
                                            at thicker wall. The pore is open and this is due to the 
                                           differential thickness of wall.
                                       --- Water will be lost as long as stomata opens.

                                       ----The pore (stoma) and the guard cells make up the stomata.
                                    

Pics taken from google. Info taken from Grace's notes.

So what is Chlorophyll all about?

The green pigment chlorophyll , a vital requirement of Photosynthesis that captures light for the process, is located in thylakoids which makes up stacks of grana which is plural for granum.The grana and stroma which is a fluid where reactions takes place and sugars are created. Both the stroma and grana make up a chloroplast, a feature in the leaf cell. The leaf where chloroplasts are mainly found is the primary site for Photosynthesis.

These thylakoids contain chlorophyll, which are sitting on & in the membrane of the thylakoids.Hence, we can say say that photosynthesis occurs on the thylakoid membrane.

The chloroplast Structure is very elaborate, so as to increase surface area to volume ratio. This will allow more chlorophyll to be packed into the thylakoid membrane.

Below is a 3D model of a chloroplast!

When absorbing light, chlorophyll absorbs strongly in the blue and red regions of the electromagnetic spectrum(EMS). It absorbs weakly in the green regions of the EMS because the green surface of the leaf will reflect green light.

 Chlorophyll plays a big part in Photosynthesis. Aquatic organisms like Cyanobacteria which is bluish-green and normally found at volcanic areas have chlorophyll that allows them to photosynthesize too. Thus, all photosynthetic organisms are not plants. However, while some photosynthetic organisms are plants, all plants are not photosynthetic like Rafflesia, Indian Pipe and the Balanophora species.These plants usually depends on the fungus in the ground soil that takes the other photosynthetic plant's nutrients and fuses it cells into the these non photosynthetic plants.       

Pic taken from GOOGLE IMAGES and info taken from Nicole's notes.

Indian Pipe

                                                            

Cyanobacteria

Energy Conversion video:)