chapter 7 Flashcards
what is photosynthesis?
a process used by certain organisms to convert solar energy into chemical energy and make carbohydrate molecules
what happens to the chemical energy created in photosynthesis?
it is released when food is broken down and harvested in cellular respiration
what happens as a result of photosynthesis?
oxygen is released into the environment.
what does photosynthesis use?
sunlight, carbon dioxide, and water
what are the two stages of photosynthesis?
the light dependent cycle and the calvin cycle
what happens when you combine carbon dioxide and water using energy from sunlight?
you get sugar and oxygen
what is the structure of the leave constituent of?
upper epidermis, mesophyll, and lower epidermis
where is the chloroplast located?
in the cells of the mesophyll
why do autotrophs convert light energy into chemical energy?
to build carbohydrate molecules
visible light constitutes…
only one of many types of electromagnetic radiation emitted from the sun
when does light energy enter the process of photosynthesis?
when pigments absorb the light
what is the purpose of light-dependent reactions?
to convert light energy into chemical energy
where is the chemical energy created in light-dependent reactions used?
in the calvin cycle, to fuel the assembly of sugar molecules
what is the first step of the light-dependent reaction?
a photon strikes photosystem ll
what happens after a photon strikes photosystem ll?
energy travels through the electron transport chain
what happens when energy travels through the electron transport chain?
hydrogen ions are pumped into the thylakoid space
what happens when hydrogen ions are pumped into the thylakoid space?
an electrochemical gradient is formed
what happens after an electrochemical gradient is formed?
The ions flow through ATP synthase from the thylakoid space into the
stroma in a process called chemiosmosis to form molecules of ATP
what happens after chemiosmosis?
photosystem l absorbs a second photon
what happens after photosystem l absorbs a second photon?
an NADPH molecule is formed
what do the calvin cycle reactions do?
they fix CO2 from the environment to build carbohydrate molecules
what catalyzes the fixation reaction of the calvin cycle?
RuBisCO
how does RuBisCO catalyze the fixation reaction?
by combining CO2 and RuBP
what are the three basic stages of the calvin cycle?
fixation, reduction, regeneration
how many turns of the calvin cycle does it take to fix six carbon atoms from CO2?
it takes six turns of the calvin cycle
how much energy input do the six turns of the calvin cycle require in the reduction stage?
12 ATP molecules and 12 NADPH molecules
how much energy input do the six turns of the calvin cycle require in the regeneration stage?
6 ATP molecules
when are the ATP and NADPH molecules made?
in the light-dependent reaction stage
