Photosynthesis Flashcards
What is the primary function of photosynthesis?
Photosynthesis transforms light energy into chemical energy by producing carbon compounds, which supply most of the chemical energy needed for life processes in ecosystems.
How does photosynthesis begin?
Photosynthesis begins with the absorption of light energy by chlorophyll and other pigments in plant cells.
What is the main product of photosynthesis?
The main product of photosynthesis is glucose, an energy-rich organic compound.
What is carbon fixation in photosynthesis?
Carbon fixation is the process where plants take in carbon dioxide from the air and use captured light energy to convert it into glucose through a series of chemical reactions.
How is glucose used by plants?
Glucose can be used immediately by the plant for cellular respiration, converted into starch for long-term storage, or used to synthesize other organic compounds like cellulose.
Why is photosynthesis crucial for ecosystems?
Photosynthesis provides the primary energy source for most ecosystems, as the chemical energy stored in carbon compounds becomes available to other organisms through food chains and food webs.
What important byproduct is released during photosynthesis?
Oxygen is released as a byproduct of photosynthesis, which is crucial for aerobic respiration in most organisms.
How does photosynthesis impact the global environment?
Photosynthesis plays a vital role in maintaining atmospheric oxygen levels, regulating the global carbon cycle, and supporting biodiversity by providing energy and organic compounds for diverse life forms.
Why is understanding photosynthesis important for addressing global challenges?
Understanding photosynthesis is crucial for comprehending energy flow in ecosystems and addressing global challenges like climate change and food security.
How do scientists use knowledge of photosynthesis in the search for extraterrestrial life?
Scientists looking for life on other planets and moons search for evidence of water and conditions suitable for photosynthesis, as these are considered essential for life as we know it.
What is the simple word equation for photosynthesis?
Carbon dioxide + Water → Glucose + Oxygen
What are the reactants in photosynthesis?
The reactants in photosynthesis are carbon dioxide (CO2) and water (H2O).
What are the products of photosynthesis?
The products of photosynthesis are glucose (C6H12O6) and oxygen (O2).
Where does the hydrogen used to produce glucose come from?
The hydrogen used to produce glucose comes from splitting water molecules during photosynthesis.
What happens to water molecules during photosynthesis?
Water molecules are split (photolysis) to provide hydrogen for glucose production and release oxygen as a byproduct.
What is the role of carbon dioxide in photosynthesis?
Carbon dioxide provides the carbon atoms needed to form glucose molecules during photosynthesis.
Why is glucose the primary product of photosynthesis?
Glucose is the primary product because it’s an energy-rich molecule that can be used immediately or stored for later use by the plant.
How does photosynthesis contribute to the carbon cycle?
Photosynthesis removes carbon dioxide from the atmosphere and incorporates it into organic compounds, playing a crucial role in the global carbon cycle.
What is the significance of oxygen production during photosynthesis?
Oxygen production during photosynthesis is crucial for maintaining atmospheric oxygen levels and supporting aerobic life forms.
How does understanding this conversion process enhance our knowledge of plant biology?
Understanding this conversion process helps explain how plants produce their own food, store energy, and contribute to ecosystem functioning and global atmospheric composition.
What is the simple word equation for photosynthesis?
Carbon dioxide + Water → Glucose + Oxygen
Where does the oxygen produced during photosynthesis come from?
The oxygen produced during photosynthesis comes from the splitting of water molecules.
What organisms perform photosynthesis and produce oxygen as a by-product?
Plants, algae, and cyanobacteria perform photosynthesis and produce oxygen as a by-product.
What is the process of splitting water molecules in photosynthesis called?
The process of splitting water molecules in photosynthesis is called photolysis.
Why is the production of oxygen during photosynthesis significant for life on Earth?
The production of oxygen during photosynthesis is significant because it maintains atmospheric oxygen levels and supports aerobic life forms.
How does the production of oxygen as a by-product relate to the search for extraterrestrial life?
Scientists look for evidence of oxygen and water on other planets as potential indicators of photosynthetic life forms.
What happens to the hydrogen atoms from the split water molecules?
The hydrogen atoms from split water molecules are used in the production of glucose during photosynthesis.
How does understanding oxygen production in photosynthesis contribute to our knowledge of the carbon cycle?
Understanding oxygen production in photosynthesis helps explain how atmospheric oxygen is replenished and how carbon dioxide is removed from the atmosphere, contributing to the global carbon cycle.
What role does chlorophyll play in the production of oxygen during photosynthesis?
Chlorophyll captures light energy, which is used to split water molecules, resulting in the production of oxygen as a by-product.
How does the production of oxygen as a by-product of photosynthesis benefit aquatic ecosystems?
Oxygen produced by aquatic plants, algae, and cyanobacteria dissolves in water, providing dissolved oxygen necessary for aquatic organisms to breathe.
What is chromatography used for in photosynthesis studies?
Chromatography is used for the separation and identification of photosynthetic pigments.
What types of chromatography can be used to separate photosynthetic pigments?
Thin-layer chromatography or paper chromatography can be used.
How are photosynthetic pigments identified after chromatographic separation?
Photosynthetic pigments are identified by their color and Rf values.
What is an Rf value in chromatography?
Rf value is the ratio of the distance traveled by the pigment to the distance traveled by the solvent front.
How do you calculate the Rf value?
Rf value = (Distance traveled by pigment) / (Distance traveled by solvent front)
Why is it important to be able to separate and identify photosynthetic pigments?
Separating and identifying photosynthetic pigments helps understand the different pigments involved in photosynthesis and their roles.
What skills should students develop related to photosynthetic pigment chromatography?
Students should be able to perform chromatography, calculate Rf values, and identify pigments based on color and Rf values.
What are some common photosynthetic pigments that might be separated?
Common photosynthetic pigments include chlorophyll a, chlorophyll b, carotenoids, and xanthophylls.
How does the polarity of pigments affect their separation in chromatography?
More polar pigments interact more strongly with the stationary phase and travel less distance, while less polar pigments travel further.
Why might different plant species show different chromatography results?
Different plant species may have varying compositions of photosynthetic pigments, resulting in different chromatography patterns.
What happens to electrons in a pigment molecule when it absorbs light?
Electrons within the pigment molecule become excited and move to a higher energy state.
How is light energy transformed during photosynthesis?
Light energy is transformed into chemical energy when photosynthetic pigments absorb specific wavelengths of light.
Why do photosynthetic pigments absorb only certain wavelengths of light?
Each pigment has a unique molecular structure that determines which wavelengths it can absorb, allowing plants to utilize a broader spectrum of light.
What is an absorption spectrum?
An absorption spectrum shows the efficiency of light absorption at different wavelengths for a particular pigment or group of pigments.
What should be included on the horizontal axis of an absorption spectrum?
The horizontal axis of an absorption spectrum should include both wavelengths (in nanometers) and corresponding colors of light.
What does the vertical axis of an absorption spectrum represent?
The vertical axis of an absorption spectrum represents the amount of light absorbed.
Which regions of the spectrum does chlorophyll a absorb most efficiently?
Chlorophyll a shows absorption peaks in the blue and red regions of the spectrum.
How do the absorption peaks of chlorophyll b differ from chlorophyll a?
Chlorophyll b has slightly different absorption peaks compared to chlorophyll a, complementing its light-capturing ability.
In which region of the spectrum do carotenoids primarily absorb light?
Carotenoids primarily absorb light in the blue-green region of the spectrum.
Why do leaves appear green?
Leaves appear green because chlorophyll reflects green light while absorbing light in other parts of the visible spectrum.
What is an absorption spectrum?
An absorption spectrum shows how much light is absorbed by photosynthetic pigments at different wavelengths.
What is an action spectrum?
An action spectrum shows the rate of photosynthesis at different wavelengths of light.
How is an absorption spectrum measured?
An absorption spectrum is measured using a spectrophotometer.
How is an action spectrum determined?
An action spectrum is determined by measuring oxygen production or carbon dioxide consumption at various wavelengths of light.
What does the shape of an absorption spectrum typically show?
An absorption spectrum may have multiple peaks corresponding to different pigments.
What does the shape of an action spectrum typically show?
An action spectrum often has a single broad peak in the red and blue regions.
How do you plot an action spectrum?
Plot wavelength on the x-axis and rate of photosynthesis (measured by oxygen production or carbon dioxide consumption) on the y-axis, then connect the data points to create a curve.
What does an absorption spectrum indicate?
An absorption spectrum indicates which wavelengths are absorbed by photosynthetic pigments, but not necessarily used for photosynthesis.
What does an action spectrum indicate?
An action spectrum shows which wavelengths of light are most effective for driving photosynthesis.
Why are both absorption and action spectra important in studying photosynthesis?
They provide complementary information about how different wavelengths of light are absorbed and utilized in photosynthesis, helping explain plant adaptations to different light environments.
What are three factors that can be varied to investigate limiting factors in photosynthesis?
Carbon dioxide concentration, light intensity, and temperature.
How can carbon dioxide concentration be varied in an experiment?
Use sodium bicarbonate solutions of different concentrations or CO2 generators/CO2-enriched air.
How can light intensity be varied in an experiment?
Adjust distance between light source and plant, use light filters or different wattage bulbs, or employ light meters to measure intensity.
How can temperature be controlled in a photosynthesis experiment?
Use water baths or incubators, control room temperature, and monitor with thermometers.
What are some methods to measure the rate of photosynthesis?
Count oxygen bubbles from aquatic plants, measure changes in CO2 or O2 levels using gas sensors, or track biomass increase over time.
What is a hypothesis in the context of photosynthesis experiments?
A provisional explanation for the effects of limiting factors on the rate of photosynthesis that requires repeated testing.
When can hypotheses be formed in scientific research?
Hypotheses can be based on theories and then tested in an experiment, or based on evidence from an experiment already carried out.
