Lab 9, Photosynthesis

Question 1

Summary Equation for Photosynthesis

Answer 1

CO2 + H2O + Light Energy -> (CH2O)n + O2

Question 2

What is Photosynthesis?

Answer 2

The ultimate source of the organic nutrients utilized in aerobic respiration and fermentation.

Question 3

What happens during photosynthesis?

Answer 3

Plants capture light energy and convert it to chemical energy (sugar).

Question 4

What are the two stages of Photosynthesis?

Answer 4

1. the Light Reaction
2. the Calvin Cycle

Question 5

Light Reaction

Answer 5

• Light energy is trapped
• Used to form ATP and NADPH
• O2 is released as a byproduct

Question 6

Calvin Cycle

Answer 6

• ATP and NADPH is used as energy and hydrogen sources
• Reduce CO2 to sugar

Question 7

How do we detect the Uptake of Carbon Dioxide in an experiment?

Answer 7

Change in pH

Question 8

What pH indicator do we use to measure the change in pH?

Answer 8

Phenol Red

Question 9

What color is Phenol Red when the solution is acidic?

Answer 9

Yellow

Question 10

What color is Phenol Red in a basic solution?

Answer 10

Red

Question 11

If there is carbon dioxide (CO2) in the water (H2O), is the solution acidic or basic?

Answer 11

Acidic

Question 12

Why is the solution acidic when carbon dioxide is combined with water?

Answer 12

Water and carbon dioxide combines to form Carbonic Acid (H2CO3).

Question 13

Electromagnetic Spectrum

Answer 13

The range of all types of EM radiation.

Question 14

What is color?

Answer 14

A wavelength of light that is reflected off a material.

Question 15

Which color has the shortest wavelength, and which color has the longest wavelength?

Answer 15

Short: Violet
Long: Red

Question 16

What is pigment?

Answer 16

A pigment is a material that selectively absorbs certain wavelengths of light and reflects other wavelengths.

Question 17

What is the absorption spectrum?

Answer 17

It is a graph/plot that shows how much light a substance absorbs at different wavelengths.

Question 18

What makes up the absorption spectrum?

Answer 18

The wavelengths that are absorbed by the pigements in a substance.

Question 19

What tool is used to examine the absorption spectrum?

Answer 19

A spectrophotometer.

Question 20

What is on the x-axis and y-axis of the absorption spectrum?

Answer 20

X-Axis: Wavelength (nm)
Y-Axis: Absorbance

Question 21

What is Paper Chromatography?

Answer 21

A method for seperating and identifying the components of a mixture based upon differences in solubility and adsorption (attraction to paper).

Question 22

How can we identify separated components in paper chromotography?

Answer 22

The ratio of:
1. The distance traveled by the substance.
2. The distance the solvent moved.

Question 23

Retention Value, Rf

Answer 23

Distance traveled by solute/Distance traveled by solvent

Question 24

What are the different plant pigments?

Answer 24

1. Carotene (Yellow)
2. Xanthophyll (Red, Yellow)
3. Chlorophyll a1 (Grass Green)
4. Chlorophyll a (Blue Green)
5. Chlorophyll b1 (Yellow Green)
6. Chlorophyll b (Dark Yellow Green)

Question 25

Why do plants contain other pigments besides chlorophyll?

Answer 25

The other pigments can absorb wavelengths of light that chlorophyll cannot. This maximizes the amount of light captured by the sun.