Electron transport chain Flashcards
what is metabolism?
the process of energy transduction takes place through a highly integrated network of chemical reactions
biologically, about ____ of food energy is conserved as ATP and the remaining ____ is liberated as heat
40% and 60%
in adipose tissues excess dietary fuels are stored mainly as?
triacylglycerides
in muscle,liver,kidneys and other tissues excess dietary fuels are stored as?
glycogen
a disorder in which there is an imbalance between energy intake and expenditure is?
obesity
ATP is an energy rich molecule because it contains?
two phosphoanhydride bonds
how many stages we have on the extraction of energy from foodstuffs by aerobic organisms?
3 stages
functions of ATP are?
- synthesis of cellular macromolecules
- synthesis of other cellular constituents(membrane phospholipids and certain required metabolites)
- cellular movement
- transport of molecules against a concentration gradient
- generation of an electric potential across a membrane(important for nerve function)
- heat
the ATP complex requires what kind of ion to properly function?
magnesium ion
when energy can’t neither be made nor utilized in adequate amounts , the patient has a?
magnesium deficiency
plants, algae,many bacteria are considered?
autotrophs
animals, fungi and many bacteria are considered?
heterotrophs
what are chemotrophs ?
organisms that utilize the organic material synthesized by autotrophs as a source of energy
organic compound + O2= CO2 + H20 + energy
the quantitative study of energy relationships and energy conversions in biological systems is ?
bioenergetics
the first law of thermodynamics is ?
for any physical or chemical change, the total amount of energy in the universe remains constant
the second law of thermodynamics is?
in all natural processes, the entropy of the universe increases.
the degree of randomness or disorder in a system is called ?
entropy
the most valuable thermodynamic concept for understanding bioenergetics is ?
free energy
hows the free energy in an exergonic reaction ?
deltaG<0
hows the free energy in an endergonic reaction ?
deltaG>0
for a chemical reaction or mechanical process, the forward reaction or process ( from left to right as written) will tend to occur spontaneously
deltag is negative
the reverse reaction (from right to left as written) will tend to occur
if deltaGpositive
both forward and reverse reactions occur at equal rates . reaction is in equilibrium
deltaGzero
the change of free energy of a reaction is influenced by which factors?
temperature
pressure
initial concentration of reactants and products
ph of solution
heat in a chemical reaction , the __________ of the reactants or products is equal to their total bond energies
enthalpy
the products contain less bond energy than the reactants , the livberated energy is sually converted to heat and delt H is negative
exothermic reaction
the products contain more bond energy than the reactants , heat is absorbed and deltaH is positive reactions tend to proceed if they liberate energy ( if deltaH<0)
endothermic
how is the BMR measured?
usually after 8 hours of sleep, in the reclining position, in the postabsorptive state typically after 12 hour fast
virtually all of the chemical reactions in the body are exothermic, and the sum of all reactions at rest is called?
Basal Metabolic Rate(BMR)
What are the 2 basic methods in which BMR can be measured?
direct calorimetry or indirect calorimetry
the toal heat liberated by an animal is measured over time, this is?
direct calorimetry
BMR is calculated from the quantity of oxygen consumed, which is directly related to the BMR
indirect calorimetry
whats oxidation?
the loss of electrons from an atom or a molecule
what is reduction?
the gain of electrons by an atom or a molecule
the mechanism by which energy derived from fuel oxidation is conserved in the form of ATP is?
oxidative phosphorylation
the outer membrane (OMM) contains?
enzyme and transport proteins ,a nd via the pore forming protein porin , it is permeable to ions, small molecules and proteins less than 10000 Da.
large proteins must be transported via?
TOM(translocase in outer mitochondrial membrane) and TIM (translocase inner mitochondrial membrane) complexes
T/F does the mitochondrial genemo encodes 13 vital subunits of the proton pumps and ATP synthase
true
the major redox coenzymes involved in transduction of energy from fuels to ATP are?
- nicotinamide adenine dinucleotide(NAD+)
- Flavin adenine dinucleotide(FAD)
- Flavin mononucleotide ( FMN)
The energy produce when NADH and FADH2 protons reenter the mitochondrial matrix is used to synthesize ATP is known as?
oxidative phosphorylation
where the electron transport chain or respiratory chain is located ?
inner mitochondrial membrane
proteins that contain a heme prosthetic groups are?
cytochromes
which iron is involved in one electron transfer involving the Fe2+ and Fe3+ oxidation states
heme
participate in one electron transfer involving the Cu+ and Cu2+ oxidation states?
copper bound proteins
the protein components of the electron transport chain are?
- NADH dehydrogenase
- succinate dehydrogenase
- ubiquinone cythocrome c oxidoreductase , cytochrome C+
- cytochrome oxidase
which is not a aprt of an ezyme complex, it moves between complexes III and IV as freely soluble protein?
cytochrome c
complex I contains the coenzyme?
Flavin mononucleotide (FMN)
On step 1 NADH interacts with the first complex enzyme known as ?
NADH DEHYDROGENASE
what is the function of Co Q?
collects electrons from both complex I and complex II and transfers them to complex III
when NADH passes along 2 electrons to first FMN, then to an iron-sulfur protein (FeS), and finally to _______________
coenzyme Q (coQ)
what is the net affect of first ETC reaction?
to regenerate coenzyme NAD+
Which complex acts as succinate dehydrogenase(fumarate reductase) oxidizing succinate to fumarate by removing two electrons?
COMPLEX II
Complex III A.K.A ?
ubiquinone-cytochrome c oxidoreductase
reaction of CoQH2
CoQH2 passes along the 2 electrons first to cytochrome b1 heme, then b2 heme, then to an Fe.S protein, then to cytochrome c1 and finally to cytochrome C
in mammals this enzyme is a dimer with each subunit containing 11 protein subunits, an {2Fe-2S} iron-sulfur cluster, one cytochrome c1 and two cytochromes b
complex III
which is the last protein complex on the electron transport chain?
complex IV( cytochrome oxidase)
if less than four electrons are transferred in the ETC what type of molecules are formed?
free radical oxygen molecules, such as peroxide and superoxide
T/F The synthesis of ATP is driven by reverse flow of protons down the gradient
TRUE
T/F for each two protons traversing the ATP synthase complex, one molecule of ATP is formed from ADP and Pi
TRUE
What is the chemiosmotic coupling hypothesis proposed by mitchell?
the electron transport chain and oxidative phosphorylation are coupled by a proton gradient across the inner mitochondrial membrane
what acts as an ion channel that provides for a proton flux back into the mitochondrial matrix?
the Fo component of ATP synthase
what are the ADP/ATP translocators ?
adenine nucleotide translocase ( antiporter) ATP synthase Phosphate translocase (symporter)
inhibitor ROTENONE blocks electron trasnport chain where?
NADH to coenzyme Q , same point that barbiturate AMYTAL works as well
antymycin A is an antibotic the blocks where?
from cytochrome b to cytochrome c1( Complex III)
british anti lewisite (BAL), antidote to an old war gas , 1,2-dithioglycerol is an inhibitor of ?
Complex III
blocks transfer from cytochrome oxidase (complex IV) TO OXYGEN in the ETC
hydrogen cyanide carbon moxide hydrogen sulfide azide ion respiratory inhibitors
2,4 dinitrophenol (2,4 DNP) trifluorocarbonylcyanide phenylhydrazone (FCCP) are?
ETC uncoplers
only mitochondria found in Brown adipose tissue (BAT) contain an uncoupling protein called?
THERMOGENIN (UCP1) - generates heat by regulated uncoupled
in this process , free fatty acids remove purine nucleotides( ADP,ATP,GDP,GTP) inhibition of thermogenin (UCP1) which causes an influx of H+ into the matrix of the mitochondrion and bypassses the ATP synthase channel
THERMOGENESIS
Mitochondria accumulate in affected tissues gives a characteristic staining pattern of ___________ in defective muscle recognizable by light microscope
RAGGED RED FIBERS
What increases the oxidative capacity of skeletal muscle by inducing mitochondrial biogenesis?
exercise
it is a fuel sensor, and it plays a critical role in initiating the production of new mitochondria and electron transport components…?
AMP activated protein kinase.
