respiration Flashcards
what is the word equation for aerobic respiration
oxygen + glucose -> carbon dioxide + water
what is the difference between anabolism and catabolism
anabolism is building up, whilst catabolism is breaking down
why do we need energy
- active transport
- endocytosis
- exocytosis
- synthesis of large molecules from smaller ones
- replication of DNA
- muscle contraction in movement
- activation of chemicals
what do we call the reaction where we convert ATP -> ADP and Pi
hydrolysis
what type of reaction is ADP + Pi to ATP
condensation
does the reaction of ADP + Pi to ATP require energy
yes
name the enzyme involved in the reaction of ADP + Pi to ATP
ATP synthase
what is substrate level phosphorylation
a phosphate group, is transferred from donor molecule to ADP to make ATP, it takes place during respiration in the cytoplasm, during glycolysis and in the matrix during the kerbs cycle.
what is oxidative phosphorylation
it takes place in the inner mitochondrial membrane of a plant and animal cell, and it is the formation of ATP, by the addition of Pi in the presence of oxygen
what is photophosphorylation
this is the making of ATP from ADP and Pi in the presence of the light dependent stage of photosynthesis and it occurs in the thylakoid membrane in the chloroplasts
what is a redox reaction
where electrons are lost or gained
what are the 3 ways, by which oxidation reactions can occur
- H+ loss (hydrogen)
- e- loss (electrons)
- oxygen is added
what are the 3 ways by which reduction reactions, can occur
- gain of hydrogen
- gain of electrons
- loss of oxygen
what are the similarities between NAD+ and ATP
- both contain nitrogenous base adenine
- both contain phosphate group
- both contain ribose
what are coenzymes and how are they involved in metabolic reactions
- small organic, non - protein molecules that bind temporarily to the active site, either before or when the substrate binds and helps the enzymes
what are the differences between NAD+ and ATP
- ATP has 3 phosphates and NAD+ has 2
- ATP is a nucleotide and NAD + is a dinucleotide
- NAD+ has two nitrogenous bases whilst ATP has one
what is glycolysis
first stage of respiration, converts glucose into pyruvate (anaerobic process), that occurs in aerobic respiration and anaerobic respiration
what are the products of glycolysis
- pyruvate
- 2 ATP
- 2 NADH
explain how glycolysis involves oxidation although its an anaerobic process
due to triose phosphate being oxidised in order to from pyruvate
describe the role of NAD during glycolysis
gets reduced as TP (triose phosphate) gets oxidised
where does glycolysis take place
in the cytoplasm
what are the two ways, that we can re oxidise the reduced NAD with oxygen
- animals - lactate fermentation pathway
- fungi - fungi - ethanol fermentation pathway
lactate fermentation pathway
- pyruvate is being used as a H acceptor
- NADH is being oxidised
ethanol fermentation pathway
- the removal of a carbon dioxide molecule is decarboxylation
- the coenzyme that is associated with pyruvate decarboxylase is thiamine diphosphate
- ethanol accepts the hydrogen ions
- the enzyme ethanol dehydrogenase reduces ethanol + re oxidises NAD
where does the link reaction occur
matrix
where does the Krebs cycle occur
matrix
where does the oxidative phosphorylation occur
inner mitochondrial membrane
what is the link reaction
pyruvate is actively transported into the mitochondria, by a pyruvate - H+ symport
what does a pyruvate- H+ symport do
transports both together (pyruvate and H+) across into the mitochondria
what does decarboxylate mean
removal of carboxyl group
what does dehydrogenated mean
removal of hydrogen atoms
what is the name of the enzyme that causes dehydrogenation of pyruvate called
pyruvate dehydrogenase
what are the products of the link reaction
- 2 x acetyl coA
- 2 carbon dioxide released
- 2 reduced NAD
what is the Krebs cycle
a series of enzyme catalysed reactions that oxidise the acetyl group of acetyl coA
what are the products of the Krebs cycle
- 2 ATP
- 6 reduced NAD
- 2 reduced FAD
- 4 C02
what is the role of NAD+ and FAD
there job, is to carry protons and electrons that are required for oxidative phosphorylation
what are the 4 main roles of the Krebs cycle
- break down macromolecules into simpler ones, pyruvate is broken down into acetate.
- it produces H atoms that are carried by NAD (and FAD) to the electron transport chain for oxidative phosphorylation and production of ATP by chemiosmosis, which provides metabolic energy for the cell
- it regenerates the starter material (oxaloacetate), which would otherwise, be completely used up
- it is a source of intermediate compounds, used by cell in the manufacture of other important substances such as fatty acids, amino Acids and chlorophyll.
describe what happens in the link reaction
- pyruvate is decarboxylated by pyruvate decarboxylase. 1 carbon is removed per pyruvate. This is the origin of some of the carbon dioxide.
- pyruvate is dehydrogenated by pyruvate dehydrogenase. 1 hydrogen atoms are removed per pyruvate overall reducing 2 molecules of NAD per one glucose molecule
- decarboxylation and dehydrogenation creates an acetyl group (acetate)
- this combines with coenzyme A (coA) to become acetyl CoA, which carries the acetyl group to the Krebs cycle
what is oxidative phosphorylation
The formation of ATP, by adding a phosphate group to ADP, in the presence of oxygen, which is the final electron and proton acceptor.
what is the role of NAD and FAD in oxidative phosphorylation
provide the protons and electrons necessary for the process of oxidative phosphorylation to occur.
outline how water is made at the end of the electron transport chain (ETC)
- electrons are passed from the electron carrier and donated to oxygen and hydrogen ions are also added to enable oxygen to be reduced to water
why is oxygen necessary for oxidative phosphorylation
final electron carrier (donator/acceptor
explain why their is a proton gradient across the inner mitochondrial
as it allows ATP to be generate as it is pumped out of the membrane via the enzyme ATP synthase
suggest why coenzymes NAD and FAD are also sometimes called hydrogen carriers
they take up hydrogen when they become reduced, which is later used in oxidative phosphorylation
what is a respiratory substrate
an organic substance, that can be oxidised by respiration, releasing energy to make molecules of ATP.
why does increasing the number of H atoms in the molecule, increase its mean energy value
the more H atoms a molecule has, the more reduced NAD and reduced FAD that can be produced, which in turn then leads to a increased yield of ATP.
what is the RQ value
- the ratio of carbon dioxide produced by a respiring organism, to oxygen consumed in a given time. as it is a ration there are no units.
what is a haemocyometer?
a microscopic quadrat to count the number of yeast cells
why is it called a haemocytometer
originally used to count blood cells
what is the depth of the liquid on a haemocytometer
0.1mm
what is the purpose of a respirometer
to measure respiration rate.
why do we use a control tube when carrying out the respiration test with the u - tube respirometer
in order to show that yeast is responsible for the production of carbon dioxide, therefore the fluid moves from the non - control end to the control end.
explain why sodium hydroxide is present in a respirometer
in order to absorb the carbon dioxide
explain why there is dyed fluid in the manometer
to show the distance travel by fluid (used to measure the rate of respiration)
explain why is a syringe present in a respirometer
in order to force air through the apparatus, in order to equalise the pressure between trials
explain why a respirometer needs to be sealed
to ensure no gas is able to escape, or this will later the pressure, thus effecting the distance that the manometer moves.
explain why the glass beads need to be of the same volume of the organism in a respirometer
- in order to create a control version of the experiment.
- in order to ensure an equal volume of air is in each tube, so that pressure is not affected
explain why there is a control tube present in a respirometer
- to prove that maggots (or the organism) is responsible for respiration.
- in order to negate the effects that temperature may have on the pressure inside the experiment.
explain why the screw clip should remain open between trials in a respirometer.
to allow pressure to recalibrate with atmospheric pressure.
explain how a U - tube respirometer works
