Lab 9, Photosynthesis Flashcards
Summary Equation for Photosynthesis
CO2 + H2O + Light Energy -> (CH2O)n + O2
What is Photosynthesis?
The ultimate source of the organic nutrients utilized in aerobic respiration and fermentation.
What happens during photosynthesis?
Plants capture light energy and convert it to chemical energy (sugar).
What are the two stages of Photosynthesis?
- the Light Reaction
- the Calvin Cycle
Light Reaction
- Light energy is trapped
- Used to form ATP and NADPH
- O2 is released as a byproduct
Calvin Cycle
- ATP and NADPH is used as energy and hydrogen sources
- Reduce CO2 to sugar
How do we detect the Uptake of Carbon Dioxide in an experiment?
Change in pH
What pH indicator do we use to measure the change in pH?
Phenol Red
What color is Phenol Red when the solution is acidic?
Yellow
What color is Phenol Red in a basic solution?
Red
If there is carbon dioxide (CO2) in the water (H2O), is the solution acidic or basic?
Acidic
Why is the solution acidic when carbon dioxide is combined with water?
Water and carbon dioxide combines to form Carbonic Acid (H2CO3).
Electromagnetic Spectrum
The range of all types of EM radiation.
What is color?
A wavelength of light that is reflected off a material.
Which color has the shortest wavelength, and which color has the longest wavelength?
Short: Violet
Long: Red
What is pigment?
A pigment is a material that selectively absorbs certain wavelengths of light and reflects other wavelengths.
What is the absorption spectrum?
It is a graph/plot that shows how much light a substance absorbs at different wavelengths.
What makes up the absorption spectrum?
The wavelengths that are absorbed by the pigements in a substance.
What tool is used to examine the absorption spectrum?
A spectrophotometer.
What is on the x-axis and y-axis of the absorption spectrum?
X-Axis: Wavelength (nm)
Y-Axis: Absorbance
What is Paper Chromatography?
A method for seperating and identifying the components of a mixture based upon differences in solubility and adsorption (attraction to paper).
How can we identify separated components in paper chromotography?
The ratio of:
1. The distance traveled by the substance.
2. The distance the solvent moved.
Retention Value, Rf
Distance traveled by solute/Distance traveled by solvent
What are the different plant pigments?
- Carotene (Yellow)
- Xanthophyll (Red, Yellow)
- Chlorophyll a1 (Grass Green)
- Chlorophyll a (Blue Green)
- Chlorophyll b1 (Yellow Green)
- Chlorophyll b (Dark Yellow Green)
Why do plants contain other pigments besides chlorophyll?
The other pigments can absorb wavelengths of light that chlorophyll cannot. This maximizes the amount of light captured by the sun.
