respiration + photosyn Flashcards
(35 cards)
where does glycolysis occur?
cytosol of the mitochondrion
what are the products of glycolysis
two pyruvate molecule, 2NADH and 2 ATP
during glycolysis, what are the 5 pdts in the pathway
glucose to fructose 1,6 biphosphate to G3P to 1,3 biphosphoglycerate to Glycerate phosphate to pyruvate
what are the 5 main steps that occur in photosynthesis
phosphorylation of sugar
lysis
oxidation by dehydrogenation
substrate level phosphorylation
oxidative decarboxylation
what happens in the link reaction (aerobic)
pyruvate enters the mitochondrial matric by an active process via a transport protein; 2 pyruvate molecules undergo oxidative carboylation and each combines with a coenzyme A moleucle to form 2 acetyl coA molecules; 2 NADH and 2CO2 is produced
where does the link reaction occur in
mitochondrial matrix
where does krebs cycle occur in
mitochondrial matrix
outline the products of the krebs cycle
acetyl CoA to citrate to alpha ketoglutarate to oxaloacetate
outline the process of the krebs cycle
OD –> OD –> 4 –> 6–> 6 ; 6NADH and 2 FADH and 2 atp +4 CO2 produced
outline the process of oxidative phosphorylation
7steps: think movement of electrons
when molecular oxygen is available, nadh from glycolysis, the link rxna nd the krebs cycle, donates high energy electrons to the first electron carrier of the electron transport chain
the first e carrier is thus reduced and the NAD which is regenerated can pick up electrons and protons from glycolysis, the link reaction or the krebs cycle, the first electron carrier then transfers the electon to the next electron carrier and reduces it while the first carrier itself becomes reoxidised
the transfer of electrons continues in this manner until they combine with protons and molecular oxygen, the final electron acceptor to form metabolic H20 in the matrix. this reaction is catalysed by cytochrome oxidase.
as electrons are transferred down the increasingly electronegative electron carriers in the ETC, energy is released.
this energy is used to actively pump protons from the mitochondrial matrix to the intermembrane space via the electron carriers. this creates a proton gradient across the inner mitochondrial membrane as the charged protons cannot pass thru the hydrophobic core of the inner mitochondrial membrane. the energy stored in the form of a proton gradient across a membrane is known as a proton motive force.
as protons diffuse through ATP synthase down the proton gradient from the intermembrane space into the mitochondrial matrix, ATP synthase phosphorylates ADP to ATP in the matrix via chemiosmosis
FADH2 donates electrons further down the ETC compared to NADH. hence less energy is released form FADH2 during electron transfer. the regenerated FAD then can pick up electrons and protons from the krebs cycle.
where does oxidative phosphorylation occur
on the inner mitochondrial membrane, H+ in the intermembrane space
what is the total ATP from the oxidation of 1 glucose molecule
38.
what is chemiosmosis
an energy coupling mechanism that uses energy stored in the form of proton gradient across a membrane to synthesise ATP
`outline the process of anaerobic respiration (both)
10pts
in the absence of oxygen, there is no final electron acceptor to accept electrons from the ETC
electron carriers remain reduced and so NADH and FADH2 can no longer donate electrons to the ETC. hence OP cannot occur.
no regeneration of NAD and FAD thus link rxn and krebs cycle cannot occur
glycolysis can still occur as the NAD needed for glycolysis is regenerated from fermentation rxns
ATP is only produced from glycolysis.
in animals pyruvate is reduced by electrons from NADH in the presence of lactate dehydrogenase to lactate.
in yeasts pyruvate is converted to ethanal and CO2. it is then reduced by electrons from NADH in the presence of alcohol dehydrogenase to ethanol.
thus pyruvate or ethanal are the final electron acceptors during anaerobic respiration.
only 2 ATP produced per glucose molecule.
what is ATP
adenosine triphosphate; it is actually a carrier of energy. can also be used to form RNA
outline the differences between photosynthesis and aerobic respiration
features: anabolic/catabolic
energy storage
oxygen
CO2 and h20
dry mass
conditions
organelle
electron carrier
high H+ location
major reactions
outline the differences between photophosphorylation and oxidative phosphorylation
features:
location
involvement of light
source of energy for ATP synthesis
energy conversion
electron donors
electron acceptors
by-product
proton gradient
distinguish between the krebs and calvin cycle
features: location
redox reaction
carbon dioxide
ATP
substance regenerated
functions of NAD and FAD
coenzymes that serve as mobile electron carrier which transport the high-energy electrons from organic molecules to the ETC in the mitochondrial membrane
functions of ETC
generate PMF to produce ATP and regenerate NADH and FADH2 from NAD and FAD
importance of oxygen
acts as the final electron acceptor at the end of the ETC where it combines with electrons and protons to form water, o2 reoxidises the ETC so that the electron carreir NADH and FADH2 can continue donating their electrons to the chain, allowing electron flow, thereby allowing OP to continue to generate ATP by chemiosmosis.
the NAD and FAD are regenerated when NADH and FADH donate electrons to the ETC, allowing NAD and FAD to pick up more electrons and protons from glycolysis, link rxn and krebs cycle, allowing these processes to continue.
reduction of oxygen to water removes H+ from the matrix, contributing to the generation of a proton gradient across the inner mitochondrial membrane.
OUTLINE NONCYCLIC PHOTOPHOSPHORYLATION
OUTLINE CYCLIC PHOTOPHOSPHORYLATION
In cyclic photophosphorylation, electrons displaced from P700 if PS1 accepted by the primary electron acceptor Y are transferred to the middle of the 1st ETC. the elctron is transported down the ETC and is finally recycled back to PS1. energy lost during electron transfer is coupled to the formation of ATP in a manner similar to non-cyclic photophosphorylation. only PS1 is involved and only ATP is produced.
outline light independent reaction process
1: carbon fixation: CO2 combines with RuBP in the presence of the enzyme ribulose biphosphate carboxylase
2: reduction and sugar formation: GP is reduced to G3P; ATP and NADH is required
3 regeneration of RUBP . g3p is either converted to sugars or regenerate RuBP
