respiration Flashcards
oxidation
the loss of electrons from one substance to another
reducing agent
substance that is the electron donor
oxidizing agent
substance that is the electron acceptor; higher electronegativity
glycolysis
occurs in cytosol; breaks glucose into 2 molecules of pyruvate
citric acid cycle
within mitochondrial matrix; oxidizes a derivative of pyruvate to carbon dioxide
oxidative phosphorylation
inner membrane of mitochondria; constituted by electron transport + chemiosmosis
substrate level phosphorylation
happens in citric acid + glycolysis; enzyme transfers a phosphate group from substrate to ADP
glycolysis production
1 glucose->2 pyruvate; 2 ATP used, 4 ATP produced->2 ATP final
pyruvate
inside mitochondria it is converted into acetyl CoA; CO2 is released
acetyl CoA
3 NADH; FAD; ATP substrate level in Krebs
ubiquinone
hydrophic molecule that is a mobile electron carrier in the ETC
cyochromes
makes up most of the electron carriers in the ETC before oxygen
FADH2
adds its electrons to complex 2 in the ETC
ATP synthase
protein complex in the inner membrane of mitochondria that makes ATP from ADP and inorganic phosphate
chemiosmosis
energy stored in the form of hydrogen ion gradient drives this ATP synthesis process
proton gradient
protons are pumped out of the mitochondrial matrix and into the intermembrane space; H+ flows down the gradient
ATP-NADH
1 NADH generates 3 ATP
ATP production
about 32 ATP are produced during oxydative phosphorylation
alcohol fermentation
acetaldehyde reduced to ethanol; replenishes NAD+
lactic acid fermentation
pyruvate is reduced to lactate; replenishes NAD+
deamination
use of amino acids for food; amino acids much remove their amino groups
beta oxidation
breaks fatty acids down to 2 carbon fragments; enter TCA as acetyl CoA
phosphofructokinase
ATP and AMP regulate this enzyme, which controls production of energy
chlorophyll
green pigment located within chloroplast where light energy is absorbed
mesophyll
about 30-40 chloroplast organelles are found mainly in this cell in the leaf
thylakoids
thylakoid sacs within stroma stacked in grana columns; chlorophyll resides within
light reactions
light absorbed by chlorophyll drives a transfer of electrons and hydrogen from water to an acceptor called NADP+
light reaction produce
generates ATP during photophosphorlyation; NADPH; oxygen as byproduct
calvin cycle
incorporation of CO2 from air into organic molecules: carbon fixation
photosynthetic pigments
chlorophyll A-primary electron excitation; chlorophyll b-also photosynthetic; carotenoids-dissipate excess light energy
photosystem
composed of a reaction center surrounded by a number of light harvesting complexes
light harvesting complexes
pigment molecules chlorophyll a, b, and carotenoids bound to molecular proteins
reaction center
protein complex in photosystem that includes two special chlorophyll a molecules and primary electron acceptor
primary electron acceptor
enables capture of excited electron to higher energy level in redox reaction
photosystem 2
first of the photosytems known as P680; interacts with light
photosystem 1
electrons are passed down ETC from PS2; second of the photosystems known as P700
cyclic electron flow
when ATP is low; electrons recycle in PS1 and no NADPH is produced
thylakoid membrane
photosystems and ETC with H+ leaving thylakoid space and passing down gradient to stroma with ATP synthase
carbon fixation
incorporates O2 by attaching ribulose bisphosphate catalyzed by rubisco
rubisco
most abundant protein in chloroplasts and potentially on earth
Calvin cycle production
3 CO2 produces one molecule of glyceraldehyde 3 phosphate; consumes 9 ATP, 6 NADPH
C3 plants
First product of carbon fixation is the 3 carbon compound 3-phosphoglycerate
C4 plants
Carbon fixation that forms a four carbon compound as first product
Oxaloacetate
Much higher affinity for CO2 than rubisco and none for O2. Can fix carbon when rubisco cannot in hot dry climates
C4 separation
Carbon fixation occurs in mesophyll but Calvin cycle occurs in bundle sheath cells
CAM plants
Open their stomata during the night and close during the day; carbon fixation at night, Calvin cycle during the day; both mesophyll
