VI. Photosynthesis Flashcards
1
Q
overall reaction for photosynthesis
A
6CO₂ + 6H₂O + light energy → C₆H₁₂O₆ + 6O₂
2
Q
Q: How to observe leaf stomata using a microscope?
A
- slice the lower epidermis of a Rhoeo discolor leaf.
- Place it on a water-dripped glass slide and cover with a cover glass.
- Observe under a microscope first at low then high magnification.
- Draw and describe the stomata.
3
Q
Q: How to measure chlorophyll content in leaves?
A
- Crush leaves with acetone using a mortar.
- Filter the extract into an Erlenmeyer flask and cover with aluminum foil.
- Measure absorbance at 663 nm (Chl a) and 645 nm (Chl b) using a spectrophotometer.
- Use the formula to calculate chlorophyll content:
Chl a = [(12.7 x A₆₆₃) - (2.6 x A₆₄₅)] x (ml acetone/mg leaf tissue)
Chl b = [(22.9 x A₆₄₅) – (4.68 x A₆₆₃)] x (ml acetone/mg leaf tissue)
Total Chl = Chl a + Chl b
4
Q
Q: How do you separate photosynthetic pigments using chromatography?
A
- Crush spinach leaves in a mortar and drip onto marked chromatography paper.
- Let the drops dry, then drip spinach extract again (5 drops).
- Place the paper in a beaker with ether and leave for 10 minutes.
- Lift the chromatography paper and draw the results with colored pencils.
5
Q
Q: How to observe the effect of light intensity on photosynthesis?
A
- Place Hydrilla in a glass beaker and cover with a glass funnel.
- Place a test tube over the funnel.
- Fill the beaker with water and add 0.5% sodium bicarbonate.
- Expose one beaker to sunlight and place the other in a dark room.
6
Q
effect of light intensity on plant photosynthesis?
A
more light: higher O2 production
less light:
- insufficient energy to convert CO₂ into glucose
- less O2 production
7
Q
components that make up spinach extract when its separated through TLC?
A
ꞵ-carotene, chlorophyll a, chlorophyll b, xanthophylls
