cellular respiration Flashcards
autotrophic organisms
make their own food by photosynthesis
heterotrophic organisms
eat and digest other organisms
how is energy provided for other metabolic reactions
-energy in chemical bonds of food transferred to the bonds in ATP during cellular respiration providing energy for all other metabolic reactions
what is cellular respiration
process by which energy from food molecules in transferred to ATP
respiratory substrate
the substance thats broken down
main respiratory substrate used by cells
glucose
forms of waste products
-oxygen from air used in process
-carbon dioxide and water formed as waste products
how do waste products vary in different organisms
-the volume of oxygen used and volume of carbon dioxide produced change
-depending on level of activity of organism
-type of food being respired
-external factors- temperature
aerobic respiration
form of cellular respiration
-takes place in presence of oxygen
equation for aerobic respiration of glucose
-C6H12O6 + 6O2 = 6CO2 + 6H2O
-glucose + oxygen = carbon dioxide + water
features of aerobic respiration
-provides energy for all cellular reactions
-third phosphate bond broken by hydrolysis
what is breaking of ATP catalysed by
enzyme ATPase
result of breaking of ATP
ADP and free inorganic phosphate group
-exothermic reaction
reversible breakdown of ATP
phosphorylation of ADP and ATP also catalysed by ATPase
storage of ATP
-cant be stored in large amounts
-raw materials to make ATP always available
what happens once raw materials used to make ATP used up
-cellular respiration cannot continue and no more ATP is made
-onset of rigor mortis after death
-no more ATP = contracting proteins of muscles cant work and muscles lock solid
outline of aerobic respiration
-glucose- glycolysis- link reaction- krebs cycle all linked to electron transport chain
glycolysis stage of aerobic respiration
doesnt require oxygen
-little ATP produced here
-splitting of respiratory substrate begins
-molecules prepared for entry into second stage of process
krebs cycle as second stage
-needs oxygen to proceed
use of link reaction
-needed to move the products of glycolysis into the krebs cycle and the electron transport chain
enzymes in biochemical pathways
-reactions controlled by enzymes
-each enzyme specific to particular reaction- different enzymes involved
-rate of reaction controlled by inhibition of enzymes- by other chemicals in reaction chain
organisms that can respire without oxygen
-facultative organisms
few groups killed by use of oxygen
features of glycolysis
first part of respiratory pathway
-not associated with any cell organelle
-other parts of pathway take place in mitochondria
where are enzymes controlling glycolysis found
in cytoplasm
matrix of mitochondria
-contain enzymes of the krebs cycle
cristae of mitochondria
-contains stalked particles for ATP synthesis
cells with low mitochondria
-low energy requirement cells like fat cells- body cells
cells with high amount of mitochondria
-muscle- liver cells- active cells
whats not true about production of ATP
-ATP is not produced as direct result of breakdown of glucose
how is most AT produced
-from a series of oxidation and reduction reactions in electron transport chain
reduction of electrons in cells
addition of electrons
-in cells this is brought by addition of hydrogen or removal of oxygen
oxidation of electrons in cells
-removal of electrons from substance
-in cells that has oxygen added or hydrogen or electrons removed
hydrogen in cellular respiration
-hydrogen removed from compounds and picked up by hydrogen acceptor so its reduced
stage of hydrogen after being reduced
hydrogen passes to next hydrogen acceptor and along electron transport chain
result of series of linked redox reactions
-each redox reaction releases small amount of energy which is used to drive synthesis of ATP
most common hydrogen acceptor in cellular respiration
NAD- nicotinamide adenine dinucleotide
NAD as a coenzyme
one of the small molecules that assist in enzyme catalysed reactions
what happens what NAD accepts hydrogen atoms from metabolic pathway
becomes reduced form of NAD
reduced form of NAD
NADH
oxidised form of NAD
NAD+
FAD
flavin adenine dinucleotide
-another hydrogen carrier and coenzyme
-accepts hydrogen from reduced NAD and formed reduced FAD2
-each time molecule of ATP produced in process
respirometer
gives information about rate of cellular respiration by measuring the uptake of oxygen or output of carbon dioxide by whole organism
basic respirometer features
has sealed chamber containing one or more living organism
chemical used in respirometer
like soda lime or potassium hydroxide used to absorb carbon dioxide produced by respiration
-any changes in volume due to uptake of oxygen
what happens as organisms use oxygen in respirometer
-pressure reduced and fluid in manometer moves to tube containing organism
measuring volume of gas needed to return to manometer to normal
-measured by syringe
-measurement then used to calculate intake of oxygen per minute and give approximate respiration condition
how to measure effect of external conditions on respiration
changing conditions such as temperature
1- way of investigating respiration at cellular level
break open cells and centrifuge contents to get fraction that has mitochondria
-of they are supplied with glucose and oxygen they will produce ATP
2- investigating respiration at cellular level
-high resolving power of electron microscope has shown surface of inner membrane of mitochondria covered in stalked particles
-increases surface area- ideal site for enzymes to work
3 - investigating respiration at cellular level
-stalked particles and bits of membrane associated with them separated from rest of mitochondrial structure
-ATP synthesis only occurs here
