Chapter 8 Flashcards
Describe two experiments that show that plant mass is not gained from nutrients taken up from the soil, or from the mass of water
planted a tree and weighed it over a 5 year period of time, tree mass increased by 74kg and the soil only decreased by .6kg –> the mass of a tree does not come from the ground
candle and mouse in a box–> mouse dies, candle burns up all the oxygen
candle, mouse, and plant in a box–> plant produces oxygen and the mouse lives
What makes plant cells fundamentally different than animal cells?
Chloroplasts –> make their own foods, autrotrophs
Describe the structure and function of the chloroplast
Outer membrane, inner membrane, thykaloid (stacks), thykaloid membrane, stoma (open area)
Site of photosynthesis –> harnesses solar energy and converts it into chemical energy
Light + h2o + o2 + ATP + NADPH2 + co2 ==> P + sugar + NADP+
Examine Figure 8.3. What does this graph suggest about the requirements for photosynthesis. Describe how each of these three factors contributes to increasing the rate of photosynthesis
see text book
Why do plants look green? Which would you expect to promote photosynthesis, a green laser or a red laser? Why?
chlorophyll in plants reflects green lights
blue and red (carotenoids) are most useful for photosynthesis because the chloryophyll molecules of chloroplasts absorb blue and red and reflect green. This is why leaves appear green.
Give the sources of energy/molecules that are the inputs and outputs of the light-dependent reactions and light-independent (dark) reactions
Light-dependent = proteins in thylakoid membrane harness light energy
Inputs - h2o, light, ADP, P, NADP
Outputs - ATP, NADPH, o2
Light-independent = Calvin cycle uses ATP to drive endergonic reactions
Inputs - ATP, NADPH
Outputs - ADP, NADP+
Some textbooks use “dark reactions” to describe the light-independent reactions. Why is the phrase “dark” reaction possibly not an ideal phrase to use in describing these reactions?
Do not actually require darkness to proceed
-reaction proceeds regardless to amount of light as long as proper substrate compounds are available
What is the antenna complex and reaction center?
Antenna complex - array of protein and chlorophyll molecules embedded in the thylakoid membrane which transfer light energy to a chlorophyll
Reaction center - complex of several proteins, pigments, and other cofactors assembled together to execute the primary energy conversion reactions of photosynthesis
In the reaction center are groups of proteins called photosystems. What is “photosystem”? Describe the role of light, electron donors and acceptors, and chlorophyll within photosystem
Photosystem - mechanism in plants that allows chlorophyll to absorb light energy for photosynthesis
Light -> excite electrons, converts NADP to NADPH
Electron donors -> ?
Electron acceptors -> ?
chlorophyll -> ?
We now have discussed in chapters 7 and 8 substrate-level phosphorylation, oxidative phosphorylation, and photophosphorylation. Each of these processes has the same goal, what is it? What is the difference between each of the 3 of these processes?
Goal of all 3 -> Produce energy (ATP)
Substrate-level -> involves transfer of a phosphate group
Oxidative -> 2 parts - reduces o2->h2o and makes ATP using ATP synthase enzyme
Photo -> photosynthesis to make ADP->ATP
Examine Figure 8.15. How is the process of photophosphorylation through light-dependent reactions in the thylakoid membrane similar/different to the electron transport train in the inner membrane of the mitochondria?
??
Describe the inputs/outputs to the Calvin cycle. How is the similar/different from the Krebs cycle?
Calvin cycle
Inputs - ATP, NADPH, co2
Outputs - ADP, G3P, NADP+
Krebs Cycle
Inputs - acetyl CoA, NADH, ADP
Outputs - ATP, NAD+, co2, CoA
Calvin uses ATP, co2
Krebs produces ATP, co2
Give the structure and function of stomata.
Pore in the epidermis of leaves, stems, and other organs that conduct photosynthesis
Stomata allows oxygen, carbon dioxide, and water in and out of the leaf
