Friday, February 12, 2010
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 the plant or combined with nitrated in the leaf to form amino acids. this allows the plant to build proteins in order to grow.
Structures of the leaf
Other than the vascular tissues, there are other structures of the leaf which help in photosynthesis.
4. Vascular Bundle 7. Sieve tube
The vascular tissue system is important in transport. The vascular tissue system is composed of the xylem, which transport water and dissolved minerals, and phloem, which transports sucrose, nitrogen containing compounds and hormones.
The phloem is found on the lower side of the vascular bundle. The xylem in the vascular bundle is found on the upper side of the vascular bundle so that water transported to the leaf cells can diffuse into the chloroplasts faster.
The vein is supported by fibres also known as sclerenchyma, which keeps the shape of the leaf flat.
Waxy Cuticle: It covers the whole leaf and being transparent, it allows light to enter the leaf for photosynthesis. Also, it reduces evaporation through the leaf.
Upper epidermis: It is one-cell layer thick and does not contain chloroplasts for photosynthesis.
Palisade mesophyll cells: It contains the most chloroplasts, lying just below the upper epidermis of the leaf. They are closely packed to allow more cells and more chloroplasts to be near the surface. The small intercellular spaces in between them allow gaseous exchange to occur.
Spongy mesophyll cells: It has less chloroplasts than the palisade mesophyll cells and larger intercellular spaces. They store carbohydrates which are products of photosynthesis. Dissolved carbohydrates diffuse into the phloem to be transported to the rest of the plant.
Lower epidermis: It has guard cells that form stomata which allow gaseous exchange to occur. The gaseous exchange which is the intake of carbon dioxide and the release of oxygen is essential for photosynthesis. In addition, the guard cells regulate the water balance in the plant.
4. Vascular Bundle 7. Sieve tubeThe vascular tissue system is important in transport. The vascular tissue system is composed of the xylem, which transport water and dissolved minerals, and phloem, which transports sucrose, nitrogen containing compounds and hormones.
The phloem is found on the lower side of the vascular bundle. The xylem in the vascular bundle is found on the upper side of the vascular bundle so that water transported to the leaf cells can diffuse into the chloroplasts faster.
The vein is supported by fibres also known as sclerenchyma, which keeps the shape of the leaf flat.
Why is the leaf so thin?
When the leaf is thin, there will be a large surface area to volume ratio - making it ideal for diffusion and absorption. The large surface allows more sunlight to be absorbed. The leaf is thin so that the mesophyll cells are closer to the surface. This reduces the diffusion distance of carbon dioxide from the surrounding to the palisade mesophyll cells.
Leaves and leaf structure
Miss Sing showed us a picture like this today. 
This is the cross section of a leaf, showing the features important to the study of photosynthesis.
This is the cross section of a leaf, showing the features important to the study of photosynthesis.
[see video]
Chlorophyll
Yay! Today, we learned all about chlorophyll!
Chlorophyll absorbs blue and red light most strongly. Green and yellow light are not effectively absorbed by photosynthetic pigments in plants. Light of these colors are either reflected by leaves or passes through the leaves. That is why plants are green. The chlorophyll is stored in the chloroplast. The stroma is a fluid inside of the chloroplast where reactions occur and starches (sugars) are created. One thylakoid stack is called a granum. The thylakoids contains chlorophyll which captures light for photosynthesis.
This is some extra facts that Ms Sing told us.
Chlorophyll absorbs blue and red light most strongly. Green and yellow light are not effectively absorbed by photosynthetic pigments in plants. Light of these colors are either reflected by leaves or passes through the leaves. That is why plants are green. The chlorophyll is stored in the chloroplast. The stroma is a fluid inside of the chloroplast where reactions occur and starches (sugars) are created. One thylakoid stack is called a granum. The thylakoids contains chlorophyll which captures light for photosynthesis.
This is some extra facts that Ms Sing told us.
EXTRA: The stacks of sacs are connected by stromal lamellae. The lamellae act like the skeleton of the chloroplast, keeping all of the sacs a safe distance from each other and maximizing the efficiency of the organelle.
Okay, gotta go! There is more to come though!
Photosynthesis carried out by other oraganisms
http://www.kscience.co.uk/animations/photoequation.swf
Today, we had a bio and we are currently on the topic of Photosynthesis. Here are some things I learnt today!
Photosynthesis is carried out by many different organisms, ranging from plants to bacteria.
The best known form of photosynthesis is the one carried out by higher plants and algae, as well as by cyanobacteria and their relatives, which are responsible for a major part of photosynthesis in oceans. All these organisms convert carbon dioxide to organic material by reducing this gas to carbohydrates in a rather complex set of reactions.
Today, we had a bio and we are currently on the topic of Photosynthesis. Here are some things I learnt today!
Photosynthesis is carried out by many different organisms, ranging from plants to bacteria.
The best known form of photosynthesis is the one carried out by higher plants and algae, as well as by cyanobacteria and their relatives, which are responsible for a major part of photosynthesis in oceans. All these organisms convert carbon dioxide to organic material by reducing this gas to carbohydrates in a rather complex set of reactions.
By the way, in case you did not know, cyanobacteria might grow in rivers, lakes, seas and oceans. If the place it is growing in has too much nutrients, cyanobacteria will get extra nutrients and multiply!
Look at the results of my experiment!
The thing in the middle is a plant and the red thing is cyanobacteria!
The thing in the middle is a plant and the red thing is cyanobacteria!
Photosynthesis
Today is the first biology lesson for this year and we are starting of with photosynthesis!
Basically, photosynthesis is the process by which plants, some bacteria, and some protistans use energy from sunlight to produce sugar, which cellular respiration converts into ATP, which is used by all living things. The conversion of unusable sunlight energy into usable chemical energy, is associated with the actions of the green pigment chlorophyll. The photosynthetic process uses water and carbon dioxide and releases oxygen and glucose.
Basically, photosynthesis is the process by which plants, some bacteria, and some protistans use energy from sunlight to produce sugar, which cellular respiration converts into ATP, which is used by all living things. The conversion of unusable sunlight energy into usable chemical energy, is associated with the actions of the green pigment chlorophyll. The photosynthetic process uses water and carbon dioxide and releases oxygen and glucose.
Here is a simplified version of what I have just explained on photosynthesis:
http://www.kscience.co.uk/animations/photosynthsis.swf
http://www.kscience.co.uk/animations/photosynthsis.swf
Hello
HI! This blog is dedicated to my favourite topic of biology, Nutrition in Plants. I am a student who absolutely LOVES biology. I mean, how can you hate such an interesting subject?? Well, needless to say, my favourite part of Nutrition in Plants is photosynthesis. That is why most of my posts on this blog will be about photosynthesis:)
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