Photosynthesis Flashcards
Dark reactions are also known as the
Calvin cycle or light independent reactions
Respiration equation
C6 H12 O6 + 6 H2O + 6 O2 ——–> 6 CO2 + 12 H2O
What is oxidized and what is reduced in respiration
Photosynthesis equation
6 CO2 + 12 H2O ——–> C6 H12 O6 + 6 H2O + 6 O2
What is oxidized and reduced in photosynthesis
pH of stroma relative to lumen
stroma = high pH
lumen = low pH
stroma
liquid environment inside the inner membrane
grana
stack fo disks
thylakoid membranes
flattened internal membrane compartments
tubular lamella
connection between the granas
thylakoid lumen
inside the thylakoids
2 stages of photosynthesis
-Light dependent reactions
-light-independent reactions
-Light dependent reactions (3)
-capture of light energy by pigment
molecules and energy used to synthesize both ATP and NADPH.
-Occurs in the grana
-split water, release O2, produce ATP and NADPH
Light-independent (3)
-electrons carried by NADPH and ATP used to covert CO2 from inorganic to organic
-Occurs in the stroma
-Glucose produced and Glyceraldehyde three phosphate
3 Outcomes of when light hits a pigment molecule
-Energy results in heat
-Fluorescence
-Chemical reaction`
inductive resonance
-Energy from an excited electron in a pigment molecule is transferred to a neighbouring pigment molecule
photosystems (2)
-clumps of 200-300 pigment molecules that pass energy onto a reaction center molecule and trigger a light reaction
-Composed of a large antenna complex of pigments that surround the central reaction centre
what is used in Chemiosmotic synthesis of ATP
chloroplast ATP synthase
proton-motive force
establishes across thylakoid membrane utilized to synthesize ATP by chemiosmosis
cyclic electron transport (3)
-Photosystem I can also operate independently of photosystem II by using cyclic electron flow
-Keeps moving protons across thylakoid membrane without the involvement of photosystem II
-Cyclic phosphorylation happens predominantly in isolated chloroplasts and bacteria
3 reactions from the light dependent
-Oxidation of water
-Reduction of NADP+
-Formation of ATP
What is G3P
starting point of synthesis for most organic molecules
carbon fixation
captures CO2 molecules with the enzyme rubisco
reduction
NADPH and ATP convert 3PGA into G3P (higher energy molecule that builds sugars)
regeneration
Remaining G3P are used to recreate the starting RuBP
RUBISCO (3)
catalyzes 2 different reactions by
-Adding CO2 to ribulose biphosphate is known as carboxylase activity
-Adding O2 to ribulose biphosphate is known as the oxygenase activity
- transforms ribulose-5-phosphate and carbon dioxide into 3-carbon 3-phosphoglycarates
As temp rises balance of air between _____ and ______ changes and the carboxylase reaction is ____ dominant
O2
CO2
less
C3 and C4 plants (perform C/B cycle)
both yes
C3 and C4 plants (primary carbon acceptor)
C3: RUBP
C4: PEP
C3 and C4 plants (CO2 fixing enzyme)
C3: Rubisco
C4: PEP carboxylase
C3 and C4 plants (1st product CO2 fixation)
C3: 3PG
C4: Oxaloacetate
C3 and C4 plants (affinity of carboxylase for CO2)
C3: moderate
C4: high
C3 and C4 plants (leaf anatomy - photosynthetic cells)
C3: mesophyll
C4: mesophyll and bundle sheath
C3 and C4 plants (classes of chloroplasts)
C3: one
C4: two
C3 and C4 plants (photorespiration)
C3: extensive
C4: minimal
