Photosynthesis Fundamentals

Temperature

Keep the light source at a constant distance from the pondweed throughout the experiment.

To ensure that the limiting factor is being investigated within its relevant range and that the results are meaningful.

<p>As light intensity increases, the rate of photosynthesis will increase until a maximum rate is reached, at which point it will plateau.</p> Signup and view all the answers

<p>Counting bubbles of oxygen released by pondweed or measuring the increase in pH due to CO₂ absorption.</p> Signup and view all the answers

<p>Only one factor will be limiting the rate of a process at any given time, and this is the factor that is closest to its minimum value.</p> Signup and view all the answers

<p>The current atmospheric CO₂ concentration is over 400 ppm, which is significantly higher than the pre-industrial level of 270 ppm.</p> Signup and view all the answers

<p>Carbon dioxide levels have risen by more than 50% due to human activities like burning fossil fuels, leading to significant environmental consequences such as climate change.</p> Signup and view all the answers

<p>FACE experiments aim to investigate the effects of increased CO₂ concentration on plant growth and ecosystems in a more natural setting.</p> Signup and view all the answers

<p>FACE experiments include both control plots receiving regular air and experimental plots receiving elevated CO₂. By comparing the growth and carbon uptake in both plots, researchers can assess whether the increased photosynthesis in the CO₂-enriched plots can offset the increased atmospheric CO₂.</p> Signup and view all the answers

<p>Two potential consequences are increased rates of photosynthesis and potential increases in plant growth and biomass.</p> Signup and view all the answers

<p>The evidence cited is that there are already observed increases in photosynthesis and plant biomass due to rising CO₂ concentrations, and experiments with artificially increased CO₂ have shown similar results.</p> Signup and view all the answers

<p>CO₂ concentrations are monitored to ensure consistency and maintain the targeted 550 ppm level. When this level drops, CO₂ is released on the upwind side of the circles to maintain the elevated concentration.</p> Signup and view all the answers

<p>The running solvent carries the pigments up the paper and allows for separation based on different attractions between the pigments and the paper or solvent.</p> Signup and view all the answers

<p>The <em>Rf</em> value represents the ratio of the distance traveled by a pigment to the distance traveled by the solvent. It is influenced by factors such as the chemical properties of the pigment, the solvent used, and the chromatography paper or thin layer plate.</p> Signup and view all the answers

<p>Solar energy is absorbed by photosynthetic pigments, such as chlorophyll, and excites electrons in the molecule to a higher energy level. These excited electrons are then passed on to other molecules, releasing energy that is used to create chemical bonds in glucose or other carbon compounds.</p> Signup and view all the answers

<p>An absorption spectrum shows the wavelengths of light absorbed by a pigment, whereas an action spectrum shows the rate of photosynthesis at different wavelengths of light.</p> Signup and view all the answers

<p>The rate of photosynthesis can be measured by monitoring the rate of oxygen production or carbon dioxide consumption. The experiment can be conducted using LEDs at different wavelengths or color filters to vary the wavelength of light.</p> Signup and view all the answers

<p>Chlorophyll absorbs mainly red and blue wavelengths of light, while reflecting green light, which is why plants appear green.</p> Signup and view all the answers

<p>The energy of a photon is inversely proportional to its wavelength. Shorter wavelengths correspond to higher energy photons, while longer wavelengths correspond to lower energy photons.</p> Signup and view all the answers

<p>Pigments like chlorophyll absorb light energy and transfer it to other molecules, initiating the process of photosynthesis. They act as molecular antennas that capture light energy and convert it into chemical energy.</p> Signup and view all the answers

<p>Photosynthesis begins by capturing light energy using pigments, such as chlorophyll, which absorb specific wavelengths of light. This absorbed light energy is then converted into chemical energy, stored within the bonds of glucose molecules. This conversion is critical because it allows organisms to harness the energy from sunlight and use it for their metabolic processes.</p> Signup and view all the answers

<p>Splitting water molecules provides the necessary hydrogen atoms for converting carbon dioxide into glucose. The oxygen atoms released as a by-product of this splitting are also crucial for releasing energy from glucose during cellular respiration.</p> Signup and view all the answers

<p>The equation for photosynthesis is: 6CO₂ + 12H₂O + light energy → C₆H₁₂O₆ + 6O₂ + 6H₂O. Carbon dioxide (CO₂) and water (H₂O) serve as reactants, along with light energy. The products of photosynthesis are glucose (C₆H₁₂O₆) and oxygen (O₂). Water is also a product, but the net change in water molecules from the reactants to products is zero.</p> Signup and view all the answers

<p>The ratio of atoms in a glucose molecule (C₆H₁₂O₆) is 1 carbon: 2 hydrogen: 1 oxygen, while the ratio in a carbon dioxide molecule (CO₂) is 1 carbon: 2 oxygen. The difference in ratios indicates that hydrogen atoms need to be added, and some oxygen atoms need to be removed from carbon dioxide to transform it into glucose. This is achieved by splitting water molecules and using the hydrogen atoms for the conversion process.</p> Signup and view all the answers

<p>Plants use some of the glucose they produce as an energy source for their own growth and metabolic processes. Excess glucose is stored as starch for later use. The oxygen produced during photosynthesis is used for respiration in both plants and other organisms, as it is essential for releasing energy from glucose. Heterotrophic organisms, which cannot produce their own food, rely on consuming plants or other photosynthetic organisms to obtain glucose and oxygen, which they use for energy and growth.</p> Signup and view all the answers

<p>Chromatography involves separating pigments by their different solubility in a solvent. In the case of leaf pigments, the process starts by extracting pigments from a leaf using a solvent, such as propanone. Propanone is a good solvent because it dissolves the pigments in the leaf, allowing them to be separated by their different affinities for the solvent and the chromatography paper.</p> Signup and view all the answers

<p>The three main groups of organisms that carry out photosynthesis are plants, algae, and cyanobacteria. The oxygen released during photosynthesis is essential for aerobic respiration, which is the process by which most organisms, including humans, obtain energy from food. This oxygen is released into the atmosphere and is used for breathing and other processes.</p> Signup and view all the answers

<p>Light is the primary source of energy for photosynthesis. It is necessary to split water molecules, releasing hydrogen and oxygen, and providing the energy needed for the conversion of carbon dioxide into glucose. Without light, photosynthesis cannot occur.</p> Signup and view all the answers

Forecasted to rise above double the pre-industrial level in the 21st century.

Increased rates due to higher CO₂ levels, which is often a limiting factor.

Plants growing and storing carbon, reducing atmospheric CO₂.

Research method using controlled carbon dioxide release in the environment.

Tracking variables in areas to predict ecosystem responses to increased CO₂.

The process by which light energy is converted into chemical energy by plants, algae, and cyanobacteria.

Light energy absorbed by pigments like chlorophyll is transformed into chemical energy during photosynthesis.

A glucose molecule is composed of 1 carbon, 2 hydrogens, and 1 oxygen atom.

Carbon dioxide is transformed into glucose by adding hydrogen and removing oxygen using energy from light.

Twelve water molecules are split to provide hydrogen needed for glucose synthesis during photosynthesis.

The overall equation for photosynthesis is: Carbon Dioxide + Water + Light -> Glucose + Oxygen.

Oxygen is produced as a by-product of water splitting in photosynthesis; most is released into the atmosphere.

A method used to separate leaf pigments to study photosynthesis by using solvents to extract pigments from leaves.

The ratio of the distance moved by a pigment to the distance moved by the solvent.

A technique used to separate mixtures of compounds based on their movement on a chromatography strip.

Describes how pigments interact with the running solvent (hydrophobic) and the chromatography strip (hydrophilic).

A graph showing which wavelengths of light are absorbed by a pigment.

A graph showing the rate of photosynthesis at different wavelengths of light.

Electrons that gain energy from photons, allowing them to move to a higher energy level.

The distance between consecutive peaks of a wave, measured in nanometers (nm).

The factor that is nearest to its minimum and limits the rate of a process like photosynthesis.

The three main factors affecting photosynthesis are temperature, light intensity, and carbon dioxide concentration.

The variable that is changed during an experiment to test its effects on photosynthesis.

Variables that are kept constant to ensure a fair test during an experiment.

A method of measuring the rate of photosynthesis by observing the amount of oxygen produced over time.

Using a thermostatically controlled water bath to vary temperature in a photosynthesis experiment.

Changing the distance of a light source to examine its impact on the rate of photosynthesis.

Increasing carbon dioxide levels in an experiment to study its effects on photosynthesis.