Colors of leaves

Season changes
Leaves turns brown when it is autumn, but why is that so? Well, to find out the answer, we must first know what are the functions of leaves

Basically, leaves gets it's water throught the plant's root, and they also take in carbon dioxide throught their stomata. They then uses the sunlights to turn water and carbon dioxide into oxygen and glucose. The way plants uses the sunlights to turn carbon dioxide and water into oxygen and glucose is by photosynthesis. Chorophyll, which is present in chloroplast in the plant is involoved in photosynthesis. It is chloroplast which gives the plant it's green colour

As the summber ends, there somes autumn. The days also gets shorter and shorter. This is how the plants "know" to get prepared for winter.

During winter, there is very little water and sunlight for the plant to photosynthesis. Thus, the trees will rest, and live off the food they stored during the summer. They began to shut down their "food-making factory", and their green chlorophyll will disappear. As the greens fade, the leave will turn yellow-orange color. But why that color? These color is actually the actual color of the plant all along, we just can't see it during summer as the chlorophyll in the plant is still present for photosynthesis

In fall, we would usually see plants with bright red or puple color leaves. Glusoce in the leaves(Like the maple leaves) is trapped in the leaves as photosynthesis stops, and with the sunlight and the cool nights from the autumn, the leaves began to turn glucose into red color. The brown color of trees(Like the oak tree) is made from wastes left in the leaves-(More explaination on colors below)

Preparations for winter
In winter, the days are shorter and it is very hard to find water. But how do plants survive throught the winter? They have lots of method to doing so.

Some plants are called "annual" which means they would complete their life cycle in one growing season. They would die as the sinter approches, but their seeds remain, ready to germinate and sprout again in the spring. "Perennial"live for more then 2 years. This includes treesand shrubs and other herbaceous plant which have soft fleshy stems. When winter comes, their woody parts of these plants are able to survive the cold, but the above ground of the plant's part, which are the leaves and stems, will die, leaving the underground parts alive. Thus in the winter, these plants will rest and use the stored food until spring

As the plants get older, they tend to shed their older leaves and grow new ones. This is important as theis helps the plants to replace damaged leaves made by the insects, diseases, or weather. The shedding and replacments continues all the time. Thus, leaves like maple, will shed their leaves in preparations for the cold winter

"Evergreen" plants, however, keeps their leaves throught the winter. They have special leaves which are somehow resistance to the cold and moisture lost. many plants have different shape of leaves to adapt to the cold winter. Some leaves, like the pine and fir tree have long thin needle like leaves, while others, like the holly, have board leaves with tough waxy surfaces. This leaves somtimes reduce their exposed area by curling up. Evergreen plants may continue to photosynthesis, as long as they have enough water, but reaction occurs slower as the temperature is low.

During the summer, the leaves would make more food then it needs. The excess food are turned into starch. These starch are used for the autumn when daylight gets shorter. The plants will then shut down their food production
Many things occurs in the leaves of the deciduous trees before they finally fall off the branches. The leaves have always been preparing food for the trees since the start of spring. At the base of the leaves, there is a special layer called "abscission" or seperating layer. During the summer, small tubes which passes throught this layer is carrying water into the leaves, and the food back to the tree. Whereas in the fall, the cells of the abscission layer began to swell and form cork like material, reducing the cut off flow between the leaves and the trees. Glucose, as well as waste products, is trapped in the leave. Without water to renew it, the chlorophyll begin to fade off.

Does color matters?
The red and purple colors comes from anthocyanin pigments. These pigments are potent antioxidents common in many plants. For intense, red apple, purple grapes, and red wine, flowers like violets and hyacinths. In some leaves, like the maple, these pigments are formes during the autumn from the trapping of starch. But why would the leaves use energy to make these pigment even thought the leaves are going to fall off? Some scientist thought the pigments anthocyanin will help the trees keep their leaves abit longer. The pigments will protect the leaves from the sun and also lower their freezing point, thus giving frst protection. The longer the leaves remain on the tree, and more sugar, and other valuble substances can be remove from the leaves before they fall. There is another possible reason: When the leaves decay, the anthocyanin will seep into the ground, preventing other plants species from growing in the spring

The brown color comes from tannin, which is the bitter waste product. Other colors, which has been all along on the plant, become visible without the chlorophyll. The orange color come from carotene and the yellow from xantheophyll. They are all common pigments found in flowers, and even food like carrots, egg yolks, etc. We do not know their exact functions in the leae, but scientist do know that they are somehow involved in photosynthesis.

Banana and autumn leaves...? What's there in common?
Do you know that while banana are still unripe, the color green is actually chloropyll? It is the same pigment that gives the green it's green color! However, as the banana becomes ripen, the chlorophyll will break down and disappear, revealing the yellowish color which has been the banana's real color form. During the autumn, the leaves also show off theit true colors as the chloroplast breaks down. There are also another changes in the banana as it ripen. The starch changes to sugar and the flesh soften as the pectin(a carbohydrate) breaks down.

Metabolism and its info

Metabolism can be split into 2 different processes such as anabolism and catabolism
Anabolism is s the set of metabolic pathways that construct molecules from smaller units.These reactions require energy. One way of categorizing metabolic processes, whether at the cellular, organ or organism level is as 'anabolic' or as 'catabolic', which is the opposite. Anabolism is powered by catabolism, where large molecules are broken down into smaller parts and then used up in respiration. Many anabolic processes are powered by adenosine triphosphate (ATP).

Anabolic processes tend toward "building up" organs and tissues. These processes produce growth and differentiation of cells and increase in body size, a process that involves synthesis of complex molecules. Examples of anabolic processes include the growth and mineralization of bone and increases in muscle mass.

Endocrinologists have traditionally classified hormones as anabolic or catabolic, depending on which part of metabolism they stimulate. The classic anabolic hormones are the anabolic steroids, which stimulate protein synthesis and muscle growth. The balance between anabolism and catabolism is also regulated by circadian rhythms, with processes such as glucose metabolism fluctuating to match an animal's normal periods of activity throughout the day.

Catabolism is

is the set of pathways that break down molecules into smaller units and release energy.^[1] In catabolism, large molecules such as polysaccharides, lipids, nucleic acids and proteins are broken down into smaller units such as monosaccharides, fatty acids, nucleotides, and amino acids, respectively. As molecules such as polysaccharides, proteins, and nucleic acids are made from long chains of these small monomer units (mono = one + mer = part), the large molecules are called polymers (poly = many).

Cells use the monomers released from breaking down polymers to either construct new polymer molecules, or degrade the monomers further to simple waste products, releasing energy. Cellular wastes include lactic acid, acetic acid, carbon dioxide, ammonia, and urea. The creation of these wastes is usually an oxidation process involving a release of chemical free energy, some of which is lost as heat, but the rest of which is used to drive the synthesis of adenosine triphosphate (ATP). This molecule acts as a way for the cell to transfer the energy released by catabolism to the energy-requiring reactions that make up anabolism. Catabolism therefore provides the chemical energy necessary for the maintenance and growth of cells. Examples of catabolic processes include glycolysis, the citric acid cycle, the breakdown of muscle protein in order to use amino acids as substrates for gluconeogenesis and breakdown of fat in adipose tissue to fatty acids.

There are many signals that control catabolism. Most of the known signals are hormones and the molecules involved in metabolism itself. Endocrinologists have traditionally classified many of the hormones as anabolic or catabolic, depending on which part of metabolism they stimulate. The so-called classic catabolic hormones known since the early 20th century are cortisol, glucagon, and adrenaline (and other catecholamines). In recent decades, many more hormones with at least some catabolic effects have been discovered, including cytokines, orexin (also known as hypocretin), and melatonin

ATP and ADP
ATP or Adenosine Triphosphate, is a molecule so central to microbial life that its measurement is directly related to biomass energy level. ATP is an energy carrier located within living biological cells that manages all biological functions, such as food consumption, maintenance, and reproduction. Like any living creature on Earth, microorganisms require ATP to survive – without it, there would be no life! ATP is found in any living life form, from a simple one–celled organism to you and I. Our kits use sophisticated techniques to detect the simplest natural product.
Bolded words gives out the explanation for ATP and its function
ADP
After a simple reaction breaking down ATP to ADP, the energy released from the breaking of a molecular bond is the energy we use to keep ourselves alive.
Relation of ATP and Glucose

Many ATP are needed every second by a cell, so ATP is created inside them due to the demand, and the fact that organisms like ourselves are made up of millions of cells.

Glucose, a sugar that is delivered via the bloodstream, is the product of the food you eat, and this is the molecule that is used to create ATP. Sweet foods provide a rich source of readily available glucose while other foods provide the materials needed to create glucose.

This glucose is broken down in a series of enzyme controlled steps that allow the release of energy to be used by the organism. This process is called respiration.

Posted by wilber

3THREE things that I DONOT understand/confused.

What is metabolism ?

What is required for the light independant stage ?

What is required for the light dependant stage ?

What must we remember for our exams ?!

3THREE things that I have LEARNT.

Learnt alot new terms like place mitochondria, that isthe ‘factories’ containing enzymes for the chemical process of respiration. You know it is capable of breaking down glucose ? [durhs. then how is it broken down? im madd]

In the dark stage, carbon dioxide is reduced not magically but by the help of enzymes

Enzymes plays a very importantt role in our lives. In our digestion, respiration and photosynthesis.

Not only plants photosynthesize but also some bacteria and uncommon animals.

And we learnt

Photosynthesis occurs in two stages. These stages are called the light reactions and the dark reactions. The light reactions take place in the presence of light. The dark reactions do not require direct light, however dark reactions in most plants occur during the day.Light reactions occur mostly in the thylakoid stacks of the grana. Here, sunlight is converted to chemical energy in the form of ATP (free energy containing molecule) and NADPH (high energy electron carrying molecule). Chlorophyll absorbs light energy and starts a chain of steps that result in the production of ATP, NADPH, and oxygen (through the splitting of water). Oxygen is released through the stomata. Both ATP and NADPH are used in the dark reactions to produce sugar.Dark reactions occur in the stomata. Carbon dioxide is converted to sugar using ATP and NADPH. This process is known as carbon fiction or the Calvin cycle. Carbon dioxide is combined with a 5-carbon sugar creating a 6-carbon sugar. The 6-carbon sugar is eventually broken-down into two molecules, glucose and fructose. These two molecules make sucrose or sugar.

to end of i wanna say from the bottom of my heart ...

ILOVEYOU ENZYMES!

maddglenn

HARLO HUMANS AGAIN! [i'm on theverge of insanity]

http://www.anaerobicrespiration.net/

Visit this web, its about respiration BUT it explains how it ties itself with digestion, in yeast, in fermentation or whatever.

ENJOY!
glenn.

Full explanation about anaerobic respiration and aerobic respiration,

Anaerobic Respiration

Anaerobic respiration is a way for an organism to produce usable energy, in the form of adenosine triphosphate, or ATP, without the involvement of oxygen; it is respiration without oxygen. This process is mainly used by prokaryotic organisms (bacteria) that live in environments devoid of oxygen. Although oxygen is not used, the process is still called respiration because the basic three steps of respiration are all used, namely glycolysis, the citric acid cycle, and the respiratory chain, or electron transport chain. It is the use of the third and final step that defines the process as respiration. In order for the electron transport chain to function, a final electron acceptor must be present to take the electron away from the system after it is used. In aerobic organisms, this final electron acceptor is oxygen. Oxygen is a highly electronegative atom and therefore is an excellent candidate for the job. In anaerobes, the chain still functions, but oxygen is not used as the final electron acceptor. Other less electronegative substances such as sulfate (SO₄), nitrate (NO₃), and sulfur (S) are used. Oftentimes, anaerobic organisms are obligate anaerobes, meaning they can only respire using anaerobic compounds and can actually die in the presence of oxygen.

Anaerobic respiration is not the same as fermentation, which does not use either the citric acid cycle or the respiratory chain (electron transport chain) and therefore, cannot be classified as respiration.

Abstract Oxyanions of arsenic and selenium can be used in microbial anaerobic respiration as terminal electron acceptors. The detection of arsenate and selenate respiring bacteria in numerous pristine and contaminated environments and their rapid appearance in enrichment culture suggest that they are widespread and metabolically active in nature. Although the bacterial species that have been isolated and characterized are still few in number, they are scattered throughout the bacterial domain and include Gram-positive bacteria, beta, gamma and epsilon Proteobacteria and the sole member of a deeply branching lineage of the bacteria, Chrysiogenes arsenatus. The oxidation of a number of organic substrates (i.e. acetate, lactate, pyruvate, glycerol, ethanol) or hydrogen can be coupled to the reduction of arsenate and selenate, but the actual donor used varies from species to species. Both periplasmic and membrane-associated arsenate and selenate reductases have been characterized. Although the number of subunits and molecular masses differs, they all contain molybdenum. The extent of the environmental impact on the transformation and mobilization of arsenic and selenium by microbial dissimilatory processes is only now being fully appreciated.

Aerobic Respiration

Aerobic respiration requires oxygen in order to generate energy (ATP). Although carbohydrates, fats, and proteins can all be processed and consumed as reactant, it is the preferred method of pyruvate breakdown from glycolysis and requires that pyruvate enter the mitochondrion in order to be fully oxidized by the Krebs cycle. The product of this process is energy in the form of ATP (Adenosine Triphosphate), by substrate-level phosphorylation, NADH and FADH₂.

Simplified reaction:	C6H12O6 (aq) + 6 O2 (g) → 6 CO2 (g) + 6 H2O (l)
	ΔG = -2880 kJ per mole of C6H12O6

The negative ΔG indicates that the products of the chemical process store less energy than the reactants and the reaction can happen spontaneously; In other words, without an input of energy.

The reducing potential of NADH and FADH₂ is converted to more ATP through an electron transport chain with oxygen as the "terminal electron acceptor". Most of the ATP produced by aerobic cellular respiration is made by oxidative phosphorylation. This works by the energy released in the consumption of pyruvate being used to create a chemiosmotic potential by pumping protons across a membrane. This potential is then used to drive ATP synthase and produce ATP from ADP. Biology textbooks often state that 38 ATP molecules can be made per oxidised glucose molecule during cellular respiration (2 from glycolysis, 2 from the Krebs cycle, and about 34 from the electron transport system). However, this maximum yield is never quite reached due to losses (leaky membranes) as well as the cost of moving pyruvate and ADP into the mitochondrial matrix and current estimates range around 29 to 30 ATP per glucose.

Aerobic metabolism is 19 times more efficient than anaerobic metabolism (which yields 2 mol ATP per 1 mol glucose). They share the initial pathway of glycolysis but aerobic metabolism continues with the Krebs cycle and oxidative phosphorylation. The post glycolytic reactions take place in the mitochondria in eukaryotic cells, and in the cytoplasm in prokaryotic cells.

Any questions do post down the comments below ty.Wilber

What happens if we remove oxygen from a plant?
As plants respire aerobically , which is a form of respiration which requires oxygen , when oxygen is removed ,it may have to respire anaerobically to provide energy needed for its activities. However, while this may provide the plant with energy, it does not produce Carbon Dioxide(CO2) that is needed for photosynthesis. Without photosynthesis , the plant will not be able to produce food(glucose) , and it will eventually die. Other than that , the process of anaerobic respiration produces the toxic ethanol , in which excess of it may kill the plant as well.
from KKXRDHX

Disagree: Due to the fact that plants needs carbon dioxide,chances of anaerobic respiration is 0% as anaerobic respiration does not give much energy and the plants do not need much energy
Wilber

Disagree: "it does not produce CO2 that is needed for photosynthesis"

eh, I thought they did? This is the equation for ANAEROBIC respiration >
Glucose -> Ethanol + Carbon Dioxide + Energy
aka
C6H12O6 -> 2C2H5OH + 2CO2 + Energy
Carbon Dioxide is produced what .. Besides, the carbon dioxide can be obtained from other means like from the air, its not necessarily a must for the CO2 to be produced by the plant.
Glenn

Other blahs/weird facts :S
When an organism, such as yeast, runs out of oxygen, it produces ethanol instead of water
When human muscles run out of oxygen, they produce lactic acid instead of water.

Ethanol and lactic acid are poisonous to yeast and humans, respectively, which is why anaerobic respiration cannot continue indefinitely in either organism.

QUESTION> So, is lactic acid harmful for plants ?
find out in 2 days ..
Posted By Glenn

Experiments

Here is the experiments we did on Thursday and Friday.

The MEALWORM experiment

Apparatus:
1 Tweezers
3 Test tube
1 Measuring cylinder [Smaller version for measuring small amount of liquid]
1 Test tube rack
3 Stoppers
3 Wire Gauze [Made into 'mini bowl' shape]
3 Copper Wires [Each about 10cm, to be attached to 'bowls' for convenience]

Materials:
70 Mealworms [Keep them in a container with holes for respiration and with bread for food]
5 Beetles
1 Bottle of Hydrogen Carbonate Indicator
1 Stopwatch

Steps:
1. Using the measuring cylinder, measure around 5ml of the Hydrogen Carbonate Indicator by gently pressing the bottle for the solution to drip out.
2. Pour the solution in the measuring cylinder into the test tube and immediately cover it with a stopper after the 'mini bowl' wire mesh have been placed inside and then place it at the test tube rack.
3. Repeat steps 1-2 for the next 2 test tubes. Once that is done, proceed to step 4.
4. Open a test tube and using the tweezers,slowly retrieving the mealworms inside the container,put 40 mealworms into the test tube. Do not tilt or shake the test tube as the solution might touch the wire mesh bowl and kill the mealworms in it. After all the mealworms are in, push in the stopper and start timing for 20 minutes and label it test tube 1.
5. Repeat step 4 but this time with only 20 mealworms and label it test tube 2.
6. The final test tube will be for us humans to breathe carbon dioxide into it. Place the last test tube near the mouth and exhale. After 10 minutes, push the stopper back in.
7. Make your observations.

Results:
Test tube 1 [40worms] >>> The Hydrogen Carbonate Indicator turns from purple to yellowish-red.
Test tube 2 [20worms] >>> The Hydrogen Carbonate Indicator turns from purple to distant yellowish-red.
Test tube 3 [Breathe] >>> The Hydrogen Carbonate Indicator turns from purple to distant yellowish-red.

Experimental error:
1. The timing for the mealworms to respire was too short to observe very obvious changes in the solution.
2. Another experimental error would be that some of us kept the test tube open while placing in the mealworms so, the solution might have turned yellowish-red due to us exhaling, not the mealworm.
3. We used 39mealworms and 1 beetle in Test tube 2. It makes it unfair as a beatle might have exhale more carbon dioxide compared to a mealworm maybe due to different respiratory needs or system.

BUSSTMEE> Did you know that limewater(saturated calcium hydroxide solution)(different from lime juice) can replace the Hydrogen Carbonate Indicator in this experiment but it would take a longer duration for the experiment to be carried out.

The Cobalt Chloride paper experiment

Materials:
Strips of Cobalt Chloride Paper [Required amount]
Ourselves

Procedure:

1. After the Cobalt Chloride paper is taken out from its container, place it near your mouth and exhale on to it. Remember not to hold it too close to prevent chloride poisoning.

Expected Results:
The cobalt chloride paper turned from blue to slightly pale pink.

Observed Results:
The cobalt chloride paper that was pale pink remained the same colour.

Experimental error:
1. The cobalt chloride paper was stored in a container that wasn't air tight.Thus, the water vapour in the air might have already change the paper from blue to pink.Therefore so we don't see a change.

Conclusion:
Gases we exhale contains water vapour.

BUSTME> Here's an experiment using COBALT CHLORIDE PAPER to determine which side of the leaf losses more water?

Which side of the leaf loses more water experiment

Materials:
4 Stripes of cobalt chloride paper [It MUST be blue]
Adhesive tape [aka, Scotch Tape, must be Transparent]
1 Potted Plant with leaves
1 Stopwatch

Procedure:
1. Tape a strip of cobalt chloride paper to each side of 2 leaves.
2. Use one leaf in the sunlight and one leaf in the shade.
3. Remember leaves need to remain attached to the plant!
4. Every 60 seconds for 10 minutes, record the color of the paper. (Is it still blue, part pink, all pink, etc.?)
5. Record your data in a table such as found below.
6. When allowed to sit in a dry location, the cobalt chloride strips will return to their original state and can be reused.

And this is what you should see:

Ta-dah! The underside part of the leaf losses more water.
Posted by Glenn edited by wilber

Firstly,lets talk about the factor that affect the photosynthesis.

The amounts of water,carbon dioxide concentration,light intensity,temperature,Pollution and Chlorophyll concentration.

The amount of water is effected by how much is taken up through the roots and how much is lost from the leaves. If less water is available in the leaf then photosynthesis will occur more slowly.


Similarly, if there is less carbon dioxide around then photosynthesis will occur more slowly. There wont be enough of the fuel (substrate) to get the reaction to work.

If there is less sun, which usually means it is cooler too, then there is less energy for photosynthesis and it occurs more slowly. So photosynthesis works best when it is warm and sunny - don't we all!

The enzymes work better in warm conditions (up to about 50ºC when enzymes start to be destroyed by heat), so if the water is too hot, the enzymes will stop work as it is being denatured.

As what we've learn in class this morning, plants also have to 'breath', they will "fight" with u in night for get more oxygen. Thus, if there is air pollution, the process of photosynthesis will also become slower by breath in the polluted air.


The concentration of chlorophyll affects the rate of reaction as they absorb the light energy without which the reactions cannot proceed. Lack of chlorophyll or deficiency of chlorophyll results in chlorosis or yellowing of leaves. It can occur due to disease, mineral deficiency or the natural process of aging (senescence). Lack of iron, magnesium, nitrogen and light affect the formation of chlorophyll and thereby causes chlorosis



In conclusion, the best condition for plants to photosynthesis are:
1)There is enough water for the plant.
2)They can get enough sunlight in day.
3)In a suitable temperature as it cannot be either too hot or too cold.
4)Clean environment with no pollution and fresh air for plant.
5)Amount of chlorophyll concentration on light capturing.


By:Tongchen edited by wilber

Our modified photosynthesis experiment

Open publication - Free publishing - More temperaure

Graphs:

comment, thnks

glenn&rena