Test 2 Ch 14 Flashcards
Proton Motive Force
combined effect of PH gradient and membrane potential across membranes that drives H+ into matrix through ATP synthase
Ubiquinone
mobile electron carrier in inner membrane, transfers electrons between complexes in ETC
Carbon Fixation
CO2 made into organic molecules using ATP and NADPH generated by light dependent reactions of photosynthesis
Photosystems
proteins in chloroplast thylakoid membrane that capture light energy + convert to chemical energy
Redox potential
measure of a molecules affinity for electrons
flow spontaneously from carriers with low potential to those with high potential
Chemiosmotic coupling
energy from ETC used to create a proton gradient which drives ATP synthesis
Brown Fat
Specialized tissue that primarily generates heat instead of ATP
Grana
stacked structures in chloroplast where light dependent reactions occur
Reactive Oxygen Species
byproducts of ETC, can damage cellular components.
Superoxide, hydrogen peroxide, hydroxyl radicals
Plastocyanin
protein that is an electron carrier between cytochrome b6-f complex and photosystem 1
cytochrome c
small electron carrier that transfers electrons from complexes
Starch
composed of amylose and amylopectine serving as plant energy storage
Light dependent reactions
first step of photosynthesis
light energy captured by chlorophyll + converted to chemical energy in form of ATP and NADPH
Oxygen byproduct
Cytochrome b6-f Complex
protein complex in thylakoid that acts as a proton pump between photosystem II and I
Contributes to proton gradient used for ATP synthesis
ADP/ATP ratio
high adp stimulates oxidative phosphorylation
low adp slows it down
Maintains high ATP/ADP ratio
Light indepedent reactions
energy from ATP and NADPH from first step used to fix CO2 to carbohydrates
Water-splitting complex
generates 4 electrons from water in photosystem 2 releases O2 as product
Uncoupling agents
H+ carriers that make the inner membrane permeable, method to shutoff ATP production
Chlorophyll
green pigment in chloroplasts that absorb light energy in blue/red wavelengths
430-660nm
contains porphyrin ring and hydrophobic tail
Acetyl-CoA formation
removal of CO2 from pyruvate and adding coenzyme A
Photosystem I
uses light to further energize electrons received from Photosystem II, produces NADPH
F1 ATPase
stationary head portion of ATP synthase the contains the catalytic sites for ATP synthesis from ADP and P
Antenna Complex
captures light energy and transfers it to reaction center in photosystems
Coupled transport
movement of molecules driven by electrochemical gradient
Membrane Potential
electrical charge difference across inner mitochondrial membrane created by separation of protons
Peripheral Stalk
secures head of ATP synthase to inner membrane
Stroma
fluid filled spaces in chloroplasts
calvin cycle and carbonx fixation take place here
pH gradient
difference in proton concentration between matrix and IMS, contributing to proton-motive force
FO complex
membrane portion of ATP synthase that has proton channel and rotates when protons flow through it
NADH dehydrogenase
first complex of ETC that accepts electrons from NADH and transfers them to ubiquinone while pumping protons
Antiport process
transport mechanism with 2 molecules move in opposite directions
Heme group
iron containing pophyrin ring structure found in cytochromes that serve as electron carrier
Respiratory Enzyme Complexes
3 large protein assemblies in Inner mitochondrial membrane that transfer electrons and pump protons during oxidative phosphorylation
Cytochrome C Oxidase
final complex of ETC that catalyzes reduction of oxygen to water while pumping protons across membrane
Conformational Change Mechanism
process where electron transport causes structural alterations to change proton affinity.
Allowing protons to change location
Plastoquinone
electron carrier from photosystem II to cytochrome b6-f complex
