lab 4 Flashcards
what is photosynthesis?
allows certain cells to take inorganic molecules from the environment and build them into enormous macromolecules. concerts light energy into chemical energy
what is cellular respiration?
converts the macromolecular raw materials into chemical energy which can be utilized by the cell
where does 90 percent of photosynthesis activity occur?
in algae present in the surface water of the ocean
which substances absorb visible light?
pigments, and they are found in the chloroplasts for plants
how can we determine the fact that chloroplasts contain multiple pigments?
through paper chromatography (separate components)
which pigment is responsible for the green colour in plants/ major pigment?
Chlorophyll a
which pigments are considered to be accessory?
Chlorophyll b, xanthophyll and carotenoids
Which pigment is this?
Chlorophyll b
Which pigment is this?
Xanthophyll
Which pigment is this?
Beta-carotene
what groups are considered to be polar?
COH, O, CO, OCH3
how can the relative polarity of a pigment be determined?
by counting the polar groups on each molecule
what provides strong evidence that chlorophylls are necessary pigments for photosynthesis?
the graph for optimal oxygen released (rate of photosynthesis) vs wavelength coincides with the graph of MOST absorption of light depending on wavelength of that light for each pigment
true or false, cell respiration is considered to be combustion?
true
what is the electron transport chain for cellular respiration?
Within the inner membrane of the mitochondria, the hydrogens and electrons released in the breakdown of glucose to CO2 and water are passed along by a sequence of redox reactions. With each passage of electrons, energy is released and coupled to the synthesis of ATP. Molecular oxygen is the final acceptor of the hydrogen atoms, resulting in the formation of water molecules
what are the two types of tests done to evaluate cell respiration?
qualitative and quantitative
which cell respiration test is qualitative and which is quantitative?
qualitative: tetrazolium test: only tells us if respiration is happening or not
quantitative: oxygen sensor test: tells us how much cell respiration is happening through the measurement of oxygen consumption
what is the tetrazolium test?
used to determine seed viability. Tetrazolium salts are reduced (producing a pink precipitate) during the process of respiration and thereby can indicate the percentage of viable seeds within a given lot
why does a seed going through cellular respiration indicate that its viable?
Germination and seedling emergence is a highly metabolic event and relies on the breakdown of starch stored in the seed for use in respiration. Therefore, a viable seed can be observed as a seed which is undergoing respiration.
how do u find the seed viability of a lot?
For example, if 100 seeds are tested and 83 present the pink precipitate upon tetrazolium testing, then seed viability of that lot will be indicated as 83%.
what is the oxygen sensor test?
allows us to see how much cellular respiration is happening in a seed lot. the oxygen sensor that we put the peas in allows us to measure how much oxygen they are consuming. oxygen sensor uses gas volume to determine this.
how is the oxygen measured in the oxygen sensor test?
in ppm
why do we need a control oxygen sensor for the oxygen sensor test? what do we do with it?
As a control, this inclusion is necessary because gas volume may be affected by factors other than respiration. Recalling the equation PV = nRT, it can be readily understood that external factors such as temperature or barometric pressure could affect the gas volume within the sensor. The changes in gas volume which occurs in the sensor containing non-viable seeds will be subtracted from the gas volume changes observed in the viable or respiring seeds
what does the geranium leaf experiment allow us to see?
illustrates the requirement for light and carbon dioxide for photosynthesis
