Flashcards in Respiration Deck (52):
Give the chemical equation for the hydrolysis of ATP
Atp -----> ADP + Pi
Why is ATP made when energy can come from chemical potential energy from within organic molecules ?
It is more manageable
Give uses of ATP
What are anabolic and catabolic reactions?
Anabolic build larger molecules from small ones
Catabolic break large molecules to smaller ones
What type pf bond forms between phosphate groups in ATP?
Why is ATP easily broken down?
Negative charges between the phosphate groups causes easy repulsion
Readily broken by enzymes
Where does glycolysis occur?
How many ATP is formed from glycolysis , what is the net gain
4 but 2 used in first step therefore net gain is 2
How many molecules of NAD are reduced in glycolysis?
Give the five steps of glycolysis by naming the substances present
Glucose phosphate (uses one ATP)
Hexose Bisphosphate (uses another ATP)
Two triose phosphates
Two pyruvates (releases 2 ATP and 1 NADH each )
Why is it beneficial to respire anaerobically?
Because this recycles NADH to NAD, this means that NAD can be imput back into glycolysis which creates another 2 ATP
Why does the Cristae of the mitochondria have a large surface area?
More ATP synthase molecules
More electron carriers
How and where is pyruvate moved to for the link reaction?
To the matrix of the mitochondria by H+ symport proteins
What is a symport protein?
A protein carrier that takes two substrates in the same direction
Describe the link reaction
Pyruvate is decarboxylated
reduces an NAD to NADH
froms an acetyl group
Coenzyme A joins the acetyl group
Makes acetyl coneznyme A
Per molecule of glucose what is made in link reaction?
2 NADH 2CO2
_______level phosphorylation occurs in the krebs cycle.
Substrate level phosphorylation
Give the total number of substances formed by the Krebs cycle
Describe the process that occurs in the electron carrier chain
Electrons go to first carrier
Reduce Fe3+ to Fe2+
Electron leaves Fe2+ reoxidised to Fe3+
Energy is released
Energy allows electron carriers to pump H+ ions from the matrix into the intermembrane space
H+ gradient is formed
H+ re enter the matrix through ATP synthase
Causes the production of ATP
H+ meet with electrons and oxygen to form water to maintain the gradient
How do NADH and FADH give rise to ATP in oxidative phosphorylation?
They provide the hydrogen
And the electrons which split from the hydrogen
Why may the theorteical yield not be met by respiration?
ATP is used to activelt transport pyruvate to the mitochondrial matrix
Some protons are lost
What would happen if oxygen wasnt avaliable for respiration?
H+ and e- wouldn't form water
Concentration gradient would be is steep
Wouldn't diffuse through ATP synthase
NADH and FADH wouldn't off load hydorgen
Krebs and link would stop
What is purpose of aneronbic respiration?
To convert the reduced NAD back to NAD
Which can be reinputted into glycolysis
Produce more ATP
O2 becomes available after anaerobic respirations had what two things may happen to lactate?
Returned to pyruvate an added to the link reaction
Recycled to glucose
Why is lactic acid removed from the muscles when possible?
Acidic conditions damage proteins
How is the rate of respiration measured?
Describe the parts of a respirometer
Connected by a manometer
One jar has a respiring tissue and a CO2 absorber
The other jar has an inert object the same volume of occupying the same volume as respiring stuff amd CO2 absorbant
Describe what will happen in a respirometer over time as the respiring tissue has respired
O2 used by organism
Gas volume reduced, reduces pressure
Liquid in manometer is pulled towards respiring jar
How can you calculate the volume of O2 used by the respirometer?
Distance moved by liquid in manometer X piR^2
Why in a respirometer must the temperature be between 10-40 degrees?
As organisms may be in pain or
If investigating anaerobic respiration with yeast what can you use as your dependant variable?
The rate of reproduction is relative to the rate of respiration
Count the number of cells before and after
Give the respiration equation
C6H12O6 + 6O2 ----> 6CO2 + 6H2O
Give in four steps the series of events that occurs in respiration
Electron transport chain (oxidative phosphorylation)
Glucose phosphoylated (2x ATP used)
Lowers activation energy so hexose bisphosphate split to triose phosphate
Triose phosphate is oxidised, to pyruvate. NAD is reduced NADH
In the process 2 ATP produced per triose phosphate
Net gain of ATP in glycolysis
Describe the link reaction
Pyruvate actively transported from cytoplasm to mitochondrial matrix
Pyruvate oxidised by NAD = NADH
Pyruvate carboxylated = acetyl group
Acetyl combines with enzyme CoA producing acetyl CoA
Where does the krebs cycle occur?
Where does the link reaction occur?
The mitochondrial matrix
Give all the steps of the krebs cycle
Acetyl fixed to oxaloacetate forming citrate
Citrate decarboxylated and dehydrogenated (CO2 produced, NAD accepts hydrogen - NADH)
Repeated to form a four carbon molecule
Substrate level phosphorylation produces ATP
4 carbon molecule oxidised further - FAD and NAD
Enzymes rearrange make oxaloacetate again
What are NAD and FAD examples of? How do they work?
Work with dehydrogenase enzymes which catakyse the removal of hydrogen
Where does oxidative phosphorylation occur? Why here?
Inner mitochondrial membrane
Folden cristae membrane has ATP synthase carrier proteins
Give adaptations of the mitochondrial membrane to improve the rate of the electron transfer chain
Tight folding of the inner matrix more surface area therefore more atp synthase molecules
Describe oxidative phosphorylation
NADH and FADH relase their hydrogens (oxidation)
Hydrogen splits into an electron and a proton
Fe3+ in a carrier protein picks up electron (reduced) forms Fe2+
Then oxidation occurs Fe2+ ---> Fe3+ + e-
Energy transfered during redox
Active pumping of H+
Creates a concentration gradient
H+ can only get into the matrix through ATP synthase proteins
ATp synthase produces ATP when a proton passes through
What happens to the H+ and electrons when they meet at the end of the electron transport chain
Combine with water to form H2O
Describe how cyanide works as a posion
Non competitive inhibitor of the enzyme responsible for catalysing 2H+ + 2e- ---> H2O
H+ therefore isnt removed
No concentration gradient
No moving of H+ so no ATP so no respiration
Describe how anaerobic conditions prevent oxidative phosphorylation and therefore the Krebs cycle.
Protons wont combine with water
They wont be removed
No diffusion = No oxidative phosphorylation
Therefore no oxidation of NADH to NAD
NAD must be recyled for use in the krebs cycle
How does glycolysis occur in anerobic conditions?
Pyruvate is reduced to lactic acid (or ethanol in yeast)
The reduction means a complementary oxidation must be occurring
The NADH is oxidised
Hence recyled back to NAD
How does lactic acid damage proteins?
More protons present
Effects tertiary structure of proteins as protons disrupt hydrogen bonding
The ATP yield of anaerobic respiration is _____ of the aerobic yield
How are amino acids used in respiration?
Converted to glucose
How are lipids used in respiration?
Triglyceride hydrolysed to glycerol which is converted to glucose