Flashcards in bio chap 8 Deck (55)
Recall that cyanobacteria may have developed as a result of horizontal gene transfer: a bacterium carrying the genetic information for one photosystem received (from another bacterium) the genetic information for a second, distinct photosystem. What might be possible mechanisms of action for horizontal gene transfer?
***Bacteria could take up genetic information (released from dead bacteria) from their surroundings.
****Bacteria may exchange genetic information through the development of cytoplasmic connections.
***** Bacteria may become infected by a virus that carries genetic information taken from previously infected bacteria.
$$$all options are correct
Which of the following statements is true regarding the earliest photosynthetic organisms on earth
The organisms likely used inorganic molecules (H2S) as electron donors
The Z scheme refers to
the energy inputs associated with electron transport
The regeneration of RuBP typically limits the rate of photosynthesis under low light intensities. This is because
RuBP regeneration requires ATP...
All photosynthetically competent cells contain
a plasma membrane
Organisms with only one photosystem cannot
Chemicals called un-couplers can make membranes permeable to small molecules and ions. What affect might un-couplers have on photosynthesis
Decreased ATP production because the proton-gradient would decrease
The evolution of photosynthesis involved...
horizontal gene transfer and endosymbiosis
How many mol NADH are required for 12 mol RuBP to be carboxylated by rubisco
Which of the following is at the highest energy level
(1) blue light
(2) green light
(3) red light
CO2 reduction requires
ATP and NADPH
For every 6 CO2 molecules fixed, how many triose phosphates are exported from the chloroplast
In plants and algae, which of the following is a by-product of photosynthesis
Which of the following statements is true regarding the Calvin Cycle? (4 false things)
The calvin cycle is considered a "dark" rx, because it is not directly related to photosynthesis
**the calvin cycle is a carefully regulated process because excess starch can be toxic to plant cells
***the calvin cycle uses a rare (and this "rate-limiting")enzyme called rubisco
***the calvin cycle produces high energy triose phosphate only through the action of rubisco
During photosynthesis in plants and algae, is oxidized and is reduced
H20 ; CO2
PS II and PS I differ in....
H+ production, and electron donors and acceptors
During their experiments with chlorella, Calvin and Benson found no free glucose. Why do you think this is?
**glucose is stored as starch
Eukaryotes conduct all of the photosynthesis that occurs in the ocean. TRUE/FALSE
Prokaryotes account for roughly half of terrestrial photosynthesis
In plants and algae, is the source of the electrons needed for photosynthesis
PS I is a than PSII
weaker oxidant and a stronger reductant
cyclic electron transport enhances ATP production because....
electrons are transferred from ferradoxin to plastoquinone
Assuming that all is working properly, which of the following is at a higher energy level
an excited-state antennae chlorophyll
From its ground state, PS II can
absorb light energy
In addition to chlorophylls, light-harvesting antennae include other pigments. What is the benefit of these additional pigments?
Narrower range of wavelength reflection
Many photosynthetic prokaryotes are capable of cyclic electron transport only. It is likely that such organisms can but not .
Produce ATP, reduce CO2
How does the metabolism occuring in chloroplast differ from that of mitochondria
*different electron acceptors and sources
Antennae accompany rx centers promoting
collectively, most photosynthesis carried out in the ocean is performed by prokaryotes and not eukaryotes