Lesson 17: Photosynthesis Flashcards
What are the basic inputs and outputs of photosynthesis? If there are any exceptions, what are they?
- -Sunlight, carbon dioxide, and water are converted into glucose and oxygen
- -Purple Sulfur Bacteria use hydrogen sulfide
What group of organelles are chloroplasts classified as?
Plastids
What structures gather energy from the light?
Pigment (the color of the pigment is the wavelength of light that is reflected
What is another name for a photosynthetic organism (an organism which makes all its own food from ions and simple molecules)?
Autotroph
What is an organism called if it derives food/energy from other organisms?
Heterotroph
What is the basic idea behind the Calvin cycle?
That CO2 can be used to make carbs (glucose) without sunlight. CO2 is reduced and sugar is produced, and stored to be used in cellular respiration
What do the light-dependent reactions produce?
O2 from H2O
What is a thylakoid?
A vesicle-like structure on the interior of the chloroplast
What is the semi-liquid substance and space between the thylakoid and the inner membrane called?
Stroma
What is chlorophyll?
A pigment which absorbs blue and red light and transmits green light
What is a cartenoid?
- -An accessory pigment which absorbs blue and green light and transmits yellow, orange, or red light.
- -It absorbs light that the chlorophyll can’t and then passes the energy on to the chlorophyll
What types of cartenoids are there?
Carotenes and Xanthophylls
What makes up a photosystem?
- -200-300 chlorophyll molecules and their accessory pigments
- -Each has an antenna complex and a reaction center
What is the antenna complex?
When a red or blue photon strikes a pigment molecule in the antenna complex, the energy is absorbed and an electron is excited (causing a photon to bounce to another pigment). This photon—but not the electron itself—is passed along to a nearby chlorophyll molecule, exciting another electron. Photons bounce around between pigment molecules until they reach the reaction center
What is the reaction center and what occurs there?
Excited electrons are finally passed to an electron acceptor here, completing the transformation of electromagnetic energy into chemical energy.
How many types of reaction centers are there?
TWO. Photosytem 1 and Photosystem 2
What is the function of plastoquinone (PQ)?
- -It is a key molecule involved in electron transport
- -It can cross the thylakoid membrane
What protein serves as a transport “bridge” between Photosystems 1 and 2?
Plastocyanin (PC). It diffuses through the lumen of the thylakoid, and passes the electrons to photosystem 1
What are the three phases of the Calvin cycle?
- Fixation (carbon fixation), uses the enzyme rubisco combines RuBP and CO2 to make 3-phosphoglycerate
- Reduction, which uses ATP to phosphorylate 3-phosphoglycerate and then concludes when it is reduced by NADPH to produce G3P that can be used to produce glucose
- Regeneration, which takes the remaining G3P (that wasn’t used to make glucose), expends more ATP chemical energy, and regenerates RuBP that can be used again in the cycle
What is the key protein in the Calvin cycle and how many active sites does it have?
- -Rubisco
- -8 active sites
How does CO2 initially get into the chloroplasts?
Leaves have a waxy cuticle that is meant to prevent desiccation (drying out), but they also have microscopic openings called stomata (on the underside of the leaf) that are used for gas exchange
True/False: Chloroplasts have DNA?
TRUE
Where did the process of photosynthesis likely originate?
With Prokaryotes
What is a catabolic reaction?
The breaking down of complex molecules into simpler ones (releases energy)