The apoplast is important for all the plant's interaction with its environment. The main carbon source (carbon dioxide) needs to be solubilized in the apoplast before it is taken up by chloroplasts and consumed during photosynthesis. In the roots, ions diffuse into the apoplast of the epidermis before being taken up into the symplast by specific ion channels and being pulled by the plant's transpiration stream, which also occurs completely within the boundaries of the apoplast. Similarly, all gaseous molecules emitted and received by plants such as plant hormones and other pheromones must pass the apoplast. The apoplast is also a site for cell-to-cell communication. During local oxidative stress, hydrogen peroxide and superoxide anion can diffuse through the apoplast and transport a warning signal to neighboring cells. In addition, a local alkalinization of the apoplast due to such a stress can travel within minutes…
In this lab, a test was conducted to determine how the relative redox activity of chloroplasts from spinach leaves, which were performing photosynthesis, would change when in the presence or absence of light. To observe these changes in redox activity, the chloroplasts were exposed to DCPIP, a chemical that changes color according to such activity. By determining the redox activity of the chloroplasts, it could then be inferred which chloroplasts were photosynthesizing more actively than others. Redox activity, otherwise known as oxidation-reduction reactions, is the loss or gain of electrons. These two reactions, where electrons are lost through oxidation and gained as a result of reduction, are always coupled together.…
Abstract: Our group wanted to see how transpiration would happen in plants when they were in different environments. The different environments we used were humidity and room environments. We measured transpiration using the whole plant method. Our results showed that the plants in a humid environment had greater transpiration rates than the plants in the room environment.…
The location of the two systems in C4 plants is in the bundle sheath cells. The mesophyll cells that surround the bundle sheath cells do not contain Rubisco. They fix carbon dioxide by combing a 3 carbon molecule, which results in a 4 carbon acid and is transported to bundle sheath cells. The carbon molecule that is released by the 4 carbon molecule is fixed again by Rubisco, forming PGA.…
The purpose of this lab is to observe how influential light is to the construction and/or use of CO2 and O2 amongst plants. This can be examined by experimenting the effects of plants under both light and no light.…
A Hill Reaction is used to measure the rate of photosynthetic electron transport. When chloroplasts were suspended in an aqueous extract made from an acetone-leaf preparation, oxygen in measurable amounts was evolved in light.( )…
Photosynthesis is the process by which green plants, algae and some bacteria absorb light energy and use it to synthesize organic compounds. In green plants, photosynthesis occurs in chloroplasts, that contain the photosynthetic pigments. Photosynthesis occurs by slightly different processes in C3 and C4 plants. Factors which can affect this are the stomata. Plants can regulate the movements of water vapor, O2 and CO2 through the leaf surface. This is accomplished by opening and closing the stomata, usually found on the bottom…
3. Stapleton, Ann E. "Ultraviolet Radiation and Plants: Burning Questions." The Plant Cell 4 (1992): 1353-358. Print.…
This resulted in light intensity to increase as the distance from the light source decreased. The purpose of placing them at different distances was to investigate the effect of light intensity on the rate of the Hill reaction. It is expected that the DCPIP at each light intensity will reduce at different rates (Figure 1). (Figure 2) shows the rate of electrons being transferred vs. the rate of photosynthesis. It is expected that the greater the light intensity, the higher the rate of electrons being transferred, and the higher the rate of photosynthesis. This higher rate of electrons transfers results in a much faster reduction of DCPIP which makes the darker green solution turn more clear, while also decreasing its absorbance. As light intensity goes up, the metabolic activity of the chloroplast goes up and the more electrons its gives up. DCPIP absorbs these electrons and the absorbance of the DCPIP decreases. The number of electrons absorbed is measured by taking the absorbance of the solutions. Chlorophyll electrons are going to absorb light energy and than transfer the energy through redox reactions until it gets to NADP which is the final electron acceptor. Water will then split and produce oxygen electrons as well as hydrogen ions. This DCPIP is supposed to be a replacement for the NAD+ and is the artificial electron acceptor we use. As DCPIP…
Plant leaves are known to have a spongy mesophyll layer which usually contains CO2 and O2 gases within it, due to this leaves and leaf disks usually float in water. If leaves are placed in an alternate source of carbon dioxide in the form of bicarbonate ions, then photosynthesis can occur. When photosynthesis occurs, oxygen will accumulate in the air space of the mesophyll, causing the sunken leaf to become buoyant again. Cellular respiration occurs at the same time as photosynthesis in plant these, countering the processes and affecting the accumulation of oxygen in the air spaces. Therefore the buoyancy of leaf disks is an indirect measurement of the net rate of photosynthesis.…
An epidural steroid injection is a shot of steroid and numbing medicine that helps relieve pain caused by an irritated or swollen nerve root. The shot is made into the epidural space, which is the space between the spinal cord and the bones in your back (vertebrae).…
2. The soap reduced the surface tension on the leaf disks, (which are hydrophobic) and allowed the surface of the leaf to be more permeable to the solutions.…
Our class data showed that the transpiration pull was the second highest in humidity and in the dark. This data is incorrect, in this given condition because in plants, transpiration is controlled by water potential. This change in water potential in leaves causes a gradient by which water can be moved upward. When the water potential of the air was increased by the humidifier and plastic covering, less water evaporated from the leaves, decreasing the water potential gradient between the root and stem, in turn decreasing the transpiration pull. These conditions should have shown little or no transpiring.…
Steroids are natural substances with many different effects in the human body, which begin over several days. The primary use of steroids in health care is to reduce inflammation and other disease symptoms. Steroid inhalers have an important role in reducing deaths from asthma, local steroid injections are useful in treating painful joints and ligaments. Steroid creams are used extensively to treat eczema and other inflammatory skin conditions. Steroids make the whole immune system less active, which can be very useful in illnesses where there is an immune component - a huge number. Steroids are the ultimate anti-inflammatory drugs.…
The second way that steroids most likely improve athletic performance is due to the infamous phenomenon know as the placebo effect. Although I cannot give you hard evidence or studies that prove this claim, I can and will explain my reasoning for this claim. As you may know, Major League Baseball is notorious for it's players getting busted for performance enhancing drugs, aka anabolic steroids. Player's statistics have shown a vast increase when influenced by anabolic steroids. For instance, the very year player's get busted for anabolic steroid usage, their numbers in terms of batting average and home runs drop significantly. As discussed earlier, steroids do increase muscle hypertrophy which in turn would logically give players the extra strength to hit the ball over the fence. However, it is more than just home runs that seem to increase dramatically with anabolic steroid usage. Players have shown drastic increases in batting average and even on base percentage while on anabolic steroids (Grossman 2-4). It is logical to buy into the idea that the increased strength from anabolic steroids would results in more home runs due to the mass behind the swing. However, the positive correlation between steroids and batting averages, would raise more question. This is because the principal behind hits in baseball is to connect the barrel of the bat to the ball. Steroids have no effects that would explain an increase in hand-eye coordination. This would lead one to believe that players are getting big confidence boosts while on anabolic steroids.…