Why don't onions contain chlorophyll?
The practical answer to this is that they don't need chloroplasts. Think of where an onion lives and how much light it normally receives. Chloroplasts only function in the presence of light. Because it costs energy to develop chloroplasts, it is not useful for the plant to put develop them if they won't function.
However accurate, this answer is a little simplified compared to what really happens. Chloroplasts are only one type of plastid, along with chromoplasts (causing the red color of peppers and tomatoes) and amyloplasts (storing starch in potatoes and corn). None of these plastids can be assembled from raw materials within the cell of a plant. Rather they all develop from another type of plastid called a proplastid. Proplastids are small and clear. They divide at the same time the cells divide, so every cell in a plant has proplastids. However, they are difficult to see in most plants because of their size.
One piece of evidence that the proplastids exist in onion cells is easily seen. Leave an onion exposed to light for several days or weeks. It will begin to grow new green leaves. Also, some of the outer layers of the bulb (actually leaves, too), will begin to green up, as their proplastids develop into chloroplasts. It is thought that plastids may be found in all living cells of a plant, and probably are present in every cell in the early stages of development. Later they become restricted to certain cells, and are abundant only in those which have specialized functions, such as photosynthesis, storage, and color manifestation. Plastids multiply freely by division, and in this way the large numbers present in some cells are in part secured. Plastids are present in the very young meristematic dells where they are very minute, the smallest being at the limit of [light, not electron] microscopic visibility.
Is it true about half the photosynthesis on earth is performed by phytoplankton?
Yes, it is estimated that about half of the photosynthesis on Earth is performed by phytoplankton, which are tiny aquatic plants found in oceans, lakes, and rivers. These microscopic organisms are crucial for marine ecosystems and play a significant role in producing oxygen and cycling carbon dioxide.
Where do 'dark reactions' take place?
Dark reactions, also known as the Calvin cycle, take place in the stroma of chloroplasts in plant cells. These reactions use the products of the light-dependent reactions to convert carbon dioxide into glucose through a series of enzyme-catalyzed steps.
Plants need energy for photosynthesis, which is the process they use to convert sunlight into chemical energy in the form of glucose. This energy is essential for the plants to grow, develop, and produce food for themselves.
What roles does oxygen play in photosynthesis and in cellular respiration?
In photosynthesis, oxygen is a gas that is given off by the plant as a by product, which it cannot use. In cellular respiration, oxygen is used to fuel the process, and without it, h20 is not produced and the pyruvic acid will turn into lactic acid in the muscles!
How does photosynthesis occur?
Photo synthesis occurs when plants containing a pigment, chlorophyll traps the energy in the sun and uses the energy to create a chemical reaction. Then raw materials, carbon dioxide and water are combined to make sugar(glucose). The left over energy is then stored in a form of starch and carbohydrates, in the leaves, roots and stem. It then releases its main byproduct oxygen.-Zahaa Safodien
Photos of plants growing under sunlight?
I'm unable to display images. However, you can search for "plants growing under sunlight" on any search engine to find a variety of images showcasing plants thriving in natural sunlight settings.
What are the end product of Krebs Cycle?
For each 2 molecules of pyruvic acid (pyruvates) you get the following:
2 ATP Molecules
6 NADH
2 FADH2
4 CO2 (by/waste products)
Carbon dioxide
AXI
Photorespiration is a process in plants that occurs when rubisco, the enzyme responsible for carbon fixation, uses oxygen instead of carbon dioxide. This can happen in hot or dry conditions, leading to a wasteful process that reduces the efficiency of photosynthesis. Photorespiration can lower the productivity of plants.
How do substances for photosynthesis enter and leave the plant?
The gas for photosynthesis...carbon dioxide diffuses into the plant through its stomata ('holes' in the leaf's underside).
Water is transported through the plant in the xylem tube (waterproof tube that makes up part of the plants veins and covers the whole plants structure) as it is drawn up from the roots where it is absorbed. It is drawn up by the water evaporationg through the stomata.
The light obviously enters the leaf and enters the chloroplasts where it combines with the chlorophyll to provide the energy for the photosynthesis reaction.
The products from photosynthesis...glucose and oxygen are removed from the plant leaves. Glucose through the phloem tube (another of the veins) and oxygen through diffusion through the stomata or it is used up in respiration.
What are the products of the light reactions?
Adenosine triphosphate, Nicotinamide adenine dinucleotide phosphate (NADP+), NADPH, and oxygen.
More technically, non-cyclic photophosphorylation produces ATP (through an electron transport chain) for use in the cell and NADPH for use in the Calvin Cycle (light-independent reactions).
For those looking for a slightly different answer, you will want: D. all of the above
NADPH, O2 and ATP
Why do plant cells need to carry out respiration?
plant cells, like any other cell, need a continuous supply of enery to live. if a cell stop functioning it dies and eventually the whole plant or systems dies.
plant cells can do both respiration and photosyntheis, whil animal cells can only do respiration, no photosynthesis.. :D
What are the organeles within cells where energy is released from nutrient molecules?
The organelles where energy is released from nutrient molecules are called mitochondria. These organelles are often referred to as the powerhouse of the cell because they produce the majority of the cell's energy currency, known as adenosine triphosphate (ATP), through a process called cellular respiration.
Causticization process used for preparation which chemical?
The causticization process is used to create sodium hydroxide from sodium carbonate or soda ash by reacting it with calcium hydroxide. This reaction produces sodium hydroxide and calcium carbonate as byproducts.
Where do light dependent reactions take place?
Light dependent reactions occur in the thylakoid membrane of the chloroplasts in photosynthetic organisms. The products (ATP and NADPH) are used in the second stage of photosynthesis, which is called the Calvin Cycle. (Oxygen is given off as a "waste" product--lucky for us!)
Would a plant placed in an atmosphere of pure oxygen be able to conduct photosynthesis?
Yes, a plant placed in an atmosphere of pure oxygen would be able to conduct photosynthesis. However, a high concentration of oxygen can be detrimental to certain plants due to the risk of oxidative damage. Plants typically thrive in a balanced atmosphere with the right levels of oxygen and carbon dioxide for optimal photosynthesis.
How are photosynthesis and resparation?
Photosynthesis and respiration are interconnected processes in living organisms. During photosynthesis, plants and some microorganisms convert sunlight into chemical energy, producing oxygen as a byproduct. In contrast, respiration involves the breakdown of organic molecules to release energy, using oxygen and producing carbon dioxide as a waste product. Together, these processes form a balance in the carbon cycle, with photosynthesis removing carbon dioxide from the atmosphere and respiration returning it.
What process does a plant use to turn sunlight into energy for the other plants?
Plants use a process called photosynthesis to convert sunlight into energy. This process involves the absorption of light by chlorophyll in the plant's cells, which in turn triggers a series of chemical reactions that convert carbon dioxide and water into glucose (sugar) and oxygen. The plant uses the glucose as energy for growth and maintenance, while releasing oxygen as a byproduct.
What happens if no oxygen is available to accept electrons during aerobic respiration?
Without oxygen to accept electrons during aerobic respiration, the electron transport chain cannot proceed. This disrupts the production of ATP, which is the main energy source for the cell. As a result, the cell may switch to anaerobic respiration, producing less ATP and potentially leading to a build-up of lactic acid or other byproducts.
What is the basic crustal material?
The basic crustal material is primarily composed of silicate minerals such as feldspar, quartz, and mica. These minerals make up the majority of the Earth's crust and are responsible for its composition and structure.
What cells does respiration occur in?
Human body is made up with cells . Now the process of respiration occur in every single cell of your body. The oxygen is needed by each and every cell making up your body. The cells with which our body is made up of is called the somatic cells and other types of cells also occur which are called reproductive cells. In the leg and arm's
What are the main parts of a plant where photosynthesis takes place?
The main parts of a plant where photosynthesis takes place are the chloroplasts, which contain the chlorophyll pigment that captures light energy, and the mesophyll cells, which are responsible for carrying out the photosynthetic process. Additionally, the stomata on the leaves allow for gas exchange, enabling the plant to take in carbon dioxide needed for photosynthesis.
In what organelle does photosynthesis occur?
Photosynthesis occurs in the chloroplasts of plant cells. These organelles contain chlorophyll, a pigment that captures sunlight and converts it into chemical energy through the process of photosynthesis.