Topic 5A: Photosynthesis and Respiration Flashcards
What is photosynthesis?
The process by which plants, algae, and some bacteria convert light energy into chemical energy in the form of glucose using carbon dioxide and water, releasing oxygen as a by product.
What are the two stages of photosynthesis?
~Light-dependent reactions: Occur in the thylakoid membranes of the chloroplasts and use light energy to produce ATP and NADPH.
~Calvin cycle (light-independent reactions): Occur in the stroma of the chloroplasts, where ATP and NADPH are used to convert carbon dioxide into glucose.
What is the equation for photosynthesis?
6CO2 + 6H2O → C6H12O6 + 6O2
Carbon dioxide + water → glucose + oxygen
Why is chlorophyll important in photosynthesis?
Chlorophyll is a pigment that absorbs light energy, particularly in the blue and red wavelengths, and plays a key role in the light-dependent reactions of photosynthesis.
What is respiration?
Respiration is the process by which cells release energy from glucose and other organic molecules to produce ATP, which is used for cellular activities.
What is the role of ATP in respiration?
ATP (adenosine triphosphate) is the energy currency of the cell. It stores and transfers energy for various metabolic processes, including muscle contraction and active transport.
What are the two main types of respiration?
~Aerobic respiration: Requires oxygen and produces a large amount of ATP.
~Anaerobic respiration: Does not require oxygen and produces less ATP, with the byproducts varying (e.g., lactic acid or ethanol).
What is the equation for aerobic respiration?
C6H12O6 + 6O2 → 6CO2 + 6H2O
Glucose + oxygen → carbon dioxide + water + energy (ATP)
What is a limiting factor in photosynthesis?
A limiting factor is an environmental factor that limits the rate of photosynthesis. These can include light intensity, carbon dioxide concentration, and temperature.
How does light intensity affect the rate of photosynthesis?
As light intensity increases, the rate of photosynthesis increases, but only up to a certain point, beyond which it levels off because other factors become limiting.
How does carbon dioxide concentration affect the rate of photosynthesis?
Increasing carbon dioxide concentration can increase the rate of photosynthesis, as long as other factors, such as light and temperature, are not limiting.
How does temperature affect the rate of photosynthesis?
The rate of photosynthesis increases with temperature up to an optimal point. Beyond that, high temperatures can denature enzymes involved in photosynthesis, reducing the rate.
How can you measure the rate of photosynthesis in an experiment?
The rate of photosynthesis can be measured by monitoring the amount of oxygen produced (e.g., using an oxygen probe or counting oxygen bubbles), the uptake of carbon dioxide, or the increase in biomass (glucose production).
What is the Elodea experiment used to measure photosynthesis?
The Elodea (aquatic plant) experiment measures the amount of oxygen produced by counting the number of bubbles released by the plant when submerged in water, under different conditions of light intensity and carbon dioxide concentration.
What is aerobic respiration?
Aerobic respiration is the process of breaking down glucose with the presence of oxygen to release energy (ATP), carbon dioxide, and water.
What is anaerobic respiration?
Anaerobic respiration occurs when oxygen is not available, and glucose is partially broken down to produce energy (ATP) along with byproducts like lactic acid (in animals) or ethanol and carbon dioxide (in yeast).
How does aerobic respiration differ from anaerobic respiration?
Aerobic respiration requires oxygen and produces more ATP (about 36-38 molecules per glucose), while anaerobic respiration does not require oxygen and produces less ATP (about 2 molecules per glucose).
How can you measure the rate of respiration in an experiment?
The rate of respiration can be measured by monitoring the amount of carbon dioxide produced, oxygen consumed, or the temperature change during the process.
Describe an experiment to investigate oxygen consumption in yeast.
In this experiment, yeast is placed in a sealed container with glucose solution. The amount of oxygen consumed can be measured by placing a gas syringe in the apparatus and measuring the volume of oxygen used over time.
How can you measure carbon dioxide production in an experiment?
Carbon dioxide production can be measured using a limewater solution or a gas syringe, where the amount of carbon dioxide released can be observed over time.
What is a Limiting Factor?
An environmental factor that restricts the rate of a process, such as photosynthesis. Common limiting factors include light intensity, temperature, and carbon dioxide concentration.
What is Light-Dependent Reactions?
The first stage of photosynthesis, occurring in the thylakoid membranes, where light energy is absorbed by chlorophyll and used to produce ATP and NADPH.
What is the light-independent reaction (Calvin Cycle)?
The second stage of photosynthesis, occurring in the stroma, where ATP and NADPH are used to convert carbon dioxide into glucose.
What is Respiration?
The process by which cells release energy from organic molecules, particularly glucose, to produce ATP.
What is the Elodea Experiment?
An experiment using the aquatic plant Elodea to measure the rate of photosynthesis by counting oxygen bubbles produced under different environmental conditions.
