What organelle is found in a plant cell but not in a animal cell?

Photosynthesis is a process used by plants and other organisms to convert light energy into chemical energy that can later be released to fuel the organisms' activities. This chemical energy is stored in carbohydrate molecules, such as sugars, which are synthesized from carbon dioxide and water – hence the name photosynthesis, from the Greek phōs , "light", and sunthesis, "putting together". In most cases, oxygen is also released as a waste product. Most plants, most algae, and cyanobacteria perform photosynthesis; such organisms are called photoautotrophs. Photosynthesis is largely responsible for producing and maintaining the oxygen content of the Earth's atmosphere, and supplies most of the energy necessary for life on Earth.

Schematic of photosynthesis in plants. The carbohydrates produced are stored in or used by the plant.

Overall equation for the type of photosynthesis that occurs in plants

Composite image showing the global distribution of photosynthesis, including both oceanic phytoplankton and terrestrial vegetation. Dark red and blue-green indicate regions of high photosynthetic activity in the ocean and on land, respectively.

Although photosynthesis is performed differently by different species, the process always begins when energy from light is absorbed by proteins called reaction centres that contain green chlorophyll pigments. In plants, these proteins are held inside organelles called chloroplasts, which are most abundant in leaf cells, while in bacteria they are embedded in the plasma membrane. In these light-dependent reactions, some energy is used to strip electrons from suitable substances, such as water, producing oxygen gas. The hydrogen freed by the splitting of water is used in the creation of two further compounds that serve as short-term stores of energy, enabling its transfer to drive other reactions: these compounds are reduced nicotinamide adenine dinucleotide phosphate (NADPH) and adenosine triphosphate (ATP), the "energy currency" of cells.

In plants, algae and cyanobacteria, long-term energy storage in the form of sugars is produced by a subsequent sequence of light-independent reactions called the Calvin cycle; some bacteria use different mechanisms, such as the reverse Krebs cycle, to achieve the same end. In the Calvin cycle, atmospheric carbon dioxide is incorporated into already existing organic carbon compounds, such as ribulose bisphosphate (RuBP). Using the ATP and NADPH produced by the light-dependent reactions, the resulting compounds are then reduced and removed to form further carbohydrates, such as glucose.

The first photosynthetic organisms probably evolved early in the evolutionary history of life and most likely used reducing agents such as hydrogen or hydrogen sulfide, rather than water, as sources of electrons. Cyanobacteria appeared later; the excess oxygen they produced contributed directly to the oxygenation of the Earth, which rendered the evolution of complex life possible. Today, the average rate of energy capture by photosynthesis globally is approximately 130 terawatts, which is about eight times the current power consumption of human civilization. Photosynthetic organisms also convert around 100–115 billion tons (91–104 petagrams) of carbon into biomass per year.

The fact that plants receive some energy from light—in addition to air, soil, and water—was discovered in 1779 by Jan Ingenhousz.

3 0

3 years ago

Which scenario causes gene flow?

-Dominant- [34]

The best answer is c) trust me

6 0

3 years ago

In the example below the scientific method is used to solve an everyday problem. Match each component to the appropriate step in

joja [24]

Answer:

1. My toaster doesn't toast my bread. --> Observation

2. Why doesn't my toaster work? ---> ask questions

3. There is something wrong with the electrical outlet. ---> Hypothesis

4. If there is something wrong with the outlet, my coffeemaker also won't work when plugged into it. ---> Prediction

5. I plug my coffeemaker into the outlet. ---> Experiments

6. My coffeemaker works. ---> Result of experiment

Note: The question is missing some parts. The complete question is given below.

In the example below the scientific method is used to solve an everyday problem. Match each component to the appropriate step in the scientific method:

1. My toaster doesn't toast my bread.

2. Why doesn't my toaster work?

3. There is something wrong with the electrical outlet

4. If there is something wrong with the outlet, my coffeemaker also won't work when plugged into it.

5. I plug my coffeemaker into the outlet.

6. My coffeemaker works.

Explanation:

The scientific method involves the following; observations, ask questions, form a hypothesis, make predictions, design experiment to test the hypothesis, obtain results, analyze results, draw conclusions.

1. My toaster doesn't toast my bread is an observation made by the person.

2. The person then proceeds to asks questions based on the observation; Why doesn't my toaster work?

3. The next step involves making a hypothesis to try to explain the observation; "There is something wrong with the electrical outlet"

4. A prediction is then made, which is an expected outcome if the hypothesis is correct; "If there is something wrong with the outlet, my coffeemaker also won't work when plugged into it".

5. Next, an experiment is conducted to test the hypothesis whether it is true or not; "I plug my coffeemaker into the outlet".

6. Results are obtained from the experiment which in this case is, "My coffeemaker works". The result is then analyzed to see whether it supports the initial hypothesis or not. Depending on the results, new hypothesis is made and further experiments conducted until a conclusion is reached.

7 0

3 years ago