Photosynthesis General Biology Flashcards | Quizlet
14CO2 is exposed for a brief period to a green plantthat is conducting a photosynthesis in the presence of sunlight.
van Niel proposed a general reaction …
Structure of Chloroplasts
Chloroplasts are specialized organelles in plant cells for the purpose of photosynthesis. Each cell may contain 1-1000 copies of chloroplasts. Chloroplasts are double membrane structure with stacked disc-like membrane structure (called thylakoids) inside the stroma. Light reactions of photosynthesis occur in thylakoids, and dark reactions occur in stroma.
All of the sugar produced in the photosynthetic cells of plants and other organisms is derived from the initial chemical combining of carbon dioxide and water with sunlight.
Biology 1A - Photosynthesis - the light reaction - …
Light reaction and photophosphorylation
Pigments embedded on thylakoid membranes form photosystems. There are of two types: PS I P700, PS II P680. Components of photosystem I and II transfer the electrons from water to NADP via cyclic electron transfer or non-cyclic electron transfer. During electron transfer, the light energy captured by the photosynthetic organisms is transformed into the phosphate bond energy of ATP. This is called photophosphorylation. NADPH is generated during non-cyclic electron transfer.
Dark reaction – Calvin cycle
Second step of photosynthesis is called Calvin’s cycle. Because it does not require light, so it is called dark reaction. During dark reaction, the ATP and NADPH generated by light reaction are consumed to fix carbon dioxide into organic carbohydrates. The first fixed carbohydrate is a three carbon compound 3-phosphoglycerate (3PGA). The final product is a high-energy 3 carbon compound glyceraldehyde-3-phosphate (G3P) which can be used to synthesize a broad range of organic molecules. An important intermediate molecule for carbon dioxide fixation is ribulose bisphosphate (RuBP), and the enzyme catalyzing the CO2 fixation is Rubisco.
The general equation for photosynthesis is:
The product of photosynthesis is a , such as the sugar , and oxygen which is released into the atmosphere (Figure 9l-1). All of the sugar produced in the photosynthetic cells of plants and other organisms is derived from the initial chemical combining of carbon dioxide and water with sunlight (Figure 9l-1). This chemical reaction is catalyzed by acting together with other , , , , and molecules. Sugars created in photosynthesis can be later converted by the plant to starch for storage, or it can be combined with other sugar molecules to form specialized carbohydrates, such as . Sugars can also be combined with other such as nitrogen, phosphorus, and sulfur, to build complex molecules such as proteins and nucleic acids.
The of a is the amount of biomass produced through photosynthesis per unit area and time by plants, the primary producers. Primary productivity is usually expressed in units of energy (e.g., joules m day ) or in units of dry organic matter (e.g., kg m year ). Globally, primary production amounts to 243 billion metric tons of dry plant biomass per year. The total energy by plants in a community through photosynthesis is referred to as (). Because all the energy fixed by the plant is converted into sugar, it is theoretically possible to determine a plant's energy uptake by measuring the amount of sugar produced. A proportion of the energy of gross primary productivity is used by plants in a process called . Respiration provides a plant with the energy needed for various plant physiological and morphological activities. The general equation for respiration is:
Photosynthesis: An Overview Quiz | 10 Questions
The Process of Photosynthesis in Plants (With Diagram)
The chemical reaction for the completion of photosynthesis is 6CO2 + H20 + light energy --> C6H12O6 + 6O2
The Process of Photosynthesis in Plants (With Diagram) ..
Photosynthetic: Light reactions/Dark reactions | New …
A simple general equation for photosynthesis follows
What is photosynthesis and why it is important
Photosynthesis is a process during which energy from light is harvested and used to drive synthesis of organic carbohydrates from carbon dioxide and water, generating oxygen. Photosynthesis is the only way that radiant energy from the sun can be converted into organic molecules for plants and animals to consume.
How can the answer be improved?
Immediatelyafter exposure to 14CO2, the plant's photosynthetic tissue iskilled by immersing it in boiling alcohol, and all of the biochemical reactions cease.
What Is Photosynthesis? From Light Energy to Chemical …
Photosynthesis is a process where by energy from light is harvested and used to drive synthesis of organic carbohydrates from carbon dioxide and water. Photosynthesis takes place in chloroplasts and can be divided into two steps: light reactions which require light and dark reactions which do not require light. During light reaction, light energy is captured by photosystems and electrons are transferred among the electron receptors. ATP and NADPH are generated. During dark reactions, CO2 is fixed using ATP and NADPH generated by the light reactions and organic carbohydrates are synthesized via the Calvin Cycle. When the CO2 is first fixed into a 3 carbon compound 3PGA, it is called C3 pathways and these plants are called C3 plants. The disadvantage of C3 plants is that they undergo photorespiration and thus waste some energy gained in light reactions. C4 cycle is the pathway adopted by C4 plants to bypass photorespiration.
Photosynthesis is the process used by ..
After deciding to learn more about an observation or a set of observations, scientists generally begin an investigation by forming a , a tentative explanation for the observation(s). The hypothesis may not be correct, but it puts the scientist’s understanding of the system being studied into a form that can be tested. For example, the observation that we experience alternating periods of light and darkness corresponding to observed movements of the sun, moon, clouds, and shadows is consistent with either of two hypotheses: (1) Earth rotates on its axis every 24 hours, alternately exposing one side to the sun, or (2) the sun revolves around Earth every 24 hours. Suitable experiments can be designed to choose between these two alternatives. For the disappearance of the dinosaurs, the hypothesis was that the impact of a large extraterrestrial object caused their extinction. Unfortunately (or perhaps fortunately), this hypothesis does not lend itself to direct testing by any obvious experiment, but scientists can collect additional data that either support or refute it.
After a hypothesis has been formed, scientists conduct experiments to test its validity. are systematic observations or measurements, preferably made under conditions—that is, under conditions in which a single variable changes. For example, in our extinction scenario, iridium concentrations were measured worldwide and compared. A properly designed and executed experiment enables a scientist to determine whether the original hypothesis is valid. Experiments often demonstrate that the hypothesis is incorrect or that it must be modified. More experimental data are then collected and analyzed, at which point a scientist may begin to think that the results are sufficiently reproducible (i.e., dependable) to merit being summarized in a , a verbal or mathematical description of a phenomenon that allows for general predictions. A law simply says happens; it does not address the question of . One example of a law, the , which was discovered by the French scientist Joseph Proust (1754–1826), states that a chemical substance always contains the same proportions of elements by mass. Thus sodium chloride (table salt) always contains the same proportion by mass of sodium to chlorine, in this case 39.34% sodium and 60.66% chlorine by mass, and sucrose (table sugar) is always 42.11% carbon, 6.48% hydrogen, and 51.41% oxygen by mass. (For a review of common units of measurement, see Essential Skills 1 in .) The law of definite proportions should seem obvious—we would expect the composition of sodium chloride to be consistent—but the head of the US Patent Office did not accept it as a fact until the early 20th century.
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