Respiration Flashcards
What is the equation for respiration
glucose + oxygen → carbon dioxide + water + energy
C6H1206 + 6 O2 → 6 CO2 + 6 H20 + 2870kJ
What are the 4 stages of aerobic respiration
-glycolysis
-the link reaction
-kerbs cycle
-electron transport chain
If no oxygen is available what will occur
Anaerobic respiration and NAD is regenerated by reduction of pyruvate to either lactic acid or ethanol
How is are mitochondria adapted for respiration
The structure of mitochondria makes them well adapted to their function
They have a large surface area due to the presence of cristae (inner folds) which enables the membrane to hold many electron transport chain proteins and ATP synthase enzymes
More active cell types can have larger mitochondria with longer and more tightly packed cristae to enable the synthesis of more ATP because they have a larger surface area
The number of mitochondria in each cell can vary depending on cell activity
Muscle cells are more active and have more mitochondria per cell than fat cells
Where in the mitochondria does the link reaction take place
Matrix
Where in the mitochondria does krebs take place
Matrix
Where does electron transport take place
On the cristae
Give the similarities of chloroplasts and mitochondria
-both have a double membrane
-large internal membrane structure
-both fluid filled
-both contain DNA and ribosomes
Give the differences between the chloroplasts and the mitochondria
-chloroplasts have grana whereas mito have cristae
-chloroplasts have stroma and mitochondria have matrix
-choloroplasts contain chlorophyll and mito don’t
Give the process of glycolysis
-activation of glucose - glucose is phosphorylated using phosphate from 2 ATP - fructose 1,6-diphosphate is produced - this has a lower Ea
- fructose 1,6-diphosphate molecules splits into 2 TP
-TP is oxidised by 2 NAD which is reduced to 2 NADH
-TP is also dephosphorylated by removing phosphates and producing ATP
-this then produces pyruvate
-net gain of ATP
-NAD reduced
Where does glycolysis take place
Cytoplasm of the cell
What is the net yield of glycolysis per glucose is
2 ATP
+2 NADH
2 pyruvate
What is the link reaction
Pyruvate undergoes oxidative decarboxylation - oxygen and carbon removed
- electrons and hydrogen from NAD become reduced to NADH
-removal of carbon dioxide coverts the pyruvate into acetate
-the acetate then combines with CoenzymeA to form acetylCoenzymeA
What is the net yield of the link reaction per glucose
2 acetyl CoenzymeA
2 NADH
2 Carbon dioxide
where does the krebs cycle take place
- matrix of the mitochondria
what is the krebs cycle
-cycle of enzyme-controlled reactions
-main goal is to provide a continuous supply of reduced electron carriers - to be fed into the final stage of respiration
describe the process of the krebs cycle
-acetylCoA (2C) combines with Oxaloacetate (4C) to produce a 6 carbon ompound called citric acid
-cirtic acid then undergoes
-a series of oxidative decarboxylation reactions - produce 5C and then 4C
this removes hydrogen ions and electrons - picked up by NAD and is reduced to NADH
-after a 4C compound is produced it undergoes oxidation and substrate level phosphorylation
where FAD is reduced to FADH - gain H+
phosphate is removed from the intermediate to produce ATP when combined with ADP
-the next 4C compound then undergoes oxidation to regenerate the oxaloacetate
NAD reduced to NADH
what are oxidative decarboxylation reactions
where the compound looses a molecule of CO2
and a H+ ion by reducing either NAD to NADH or FAD to FADH
how many times does the Krebs cycle happen per molecule of glucose
twice as 2 pyruvates are used in glycolysis
and so 2 acetylCoA is used in krebs
what is the net products of the krebs cycle per glucose
- 4 Carbon dioxide
- 2 FADH
- 6 NADH
- 2 ATP
what is the 4th stage of aerobic respiration
electron transport chain
where does the ETC take place
cristae of the mitochondria
where do the electrons come from in ETC
the NADH and FADH produced in the previous reactions
how is the cristae adapted for the ETC
-cristae/inner membrane is folded - giving a large SA
describe the process of the ETC
-within the membrane there are a series of electron carrier protein complexes arranged in descending energy levels
-as electrons pass through the carrier protiens the energy released is used to move hydrogen ions from the matrix into the intermembrane space
-this movements sets up a large H+ ion conc gradient for the movement of H+ back into the matrix
-when the ETC reaches a enzyme ATP synthase the H+ ions are removed via facilitated diffusion
-each time a H+ ion passes through the enzyme it attaches a phosphate to an ADP thus producing ATP
-when the electrons reach the end of the ETC they are picked up by oxygen - terminal electron acceptor
-each oxygen atom picks up 2H+ and 2e- to produce a molecule of H20
2H+ + 2e- + 1/2 O2 = H2O
-this process is known as oxidative phosphorylation - because ATP is made and oxygen is used up
-chemiosmaotic theory
how many ATP is produced for every NADH
3ATP
how many ATP is produced per FADH
2 ATP
what are the overall amounts of NADH and how many ATP does this produce
-2 in glycolysis
-2 in link
-6 in krebs
10 overall = 30 ATP
what is ther overall amount of FADH and how many ATP does it produce
-2 in krebs
-4 ATP
explain why the coloured liquid in the tubing moved towards tube B
-oxygen taken up or used by thing in question
-CO2 given out is abosorbed by KOH
-volume or pressure in other tube decreases
-if diagram open to atmos - then say pressure in tube decreases below atmos
-if with another tube - then say decreases below pressure in the other tube
what happens if oxygen is not available for respiaration
-anaerobic resp occurs
-ETC cannot operate
-cells initial supply of NAD runs out
how is NAD regenerated in anaerobic respiration
-pyruvate from glycolysis is reduced
-which uses up the NADH
-oxidise NADH to NAD
-ATP continued to be made
what is pyruvate converted to in animal cells in anaerobic respiration
-lactic acid
what is the net yeild for ATP in anaerobic respiration
2 ATP compared to 38 in aerobic
in plants and microbes what s the pyruvate converted to in anaerobic resp
-ethanol - by removing CO2 and adding NADH/ reduce
-carbon dioxide
GW1516 is a performance-enhancing drug. GW1516 activates AMPK and
develops slow muscle fibres at rest.
Use diagram above to justify why professional athletes are not allowed to
take GW1516.
Do not include details of chemiosmotic theory in your answer.
- More acetylcoenzyme A would enter the Krebs cycle;
- (So) the Krebs cycle generates (more) reduced coenzymes
OR
(So more) reduced coenzymes pass their electrons to the electron
transfer chain; - (So more) ATP would be produced;
idea for more is required once - Athletes could build (slow) muscle (fibres) without exercising;
Ignore ‘develop (slow) muscle (fibres) at rest’ as in
stem of question
Accept description of not exercising, eg without
training - (Having more) slow muscle (fibres) would increase endurance;
Accept descriptions of endurance in terms of
delayed onset of anaerobic respiration
Humans synthesise more than their body mass of ATP each day. Explain why it is
necessary for them to synthesise such a large amount of ATP.
- ATP cannot be stored / is an immediate source of energy;
- ATP only releases a small amount of energy at a time;
what are 4 uses of ATP by the body
-active transport
-DNA synthesis
-movement of organelles within cells
-maintaining body temp / thermoregulation
where are fatty acids used in respiration
-the krebs cycle
describe the process of chemiosmosis
-The model states that energy from electrons passed through a chain of proteins in the membrane (the electron transport chain) is used to pump protons up their concentration gradient into the intermembrane space
-The H+ ions are then transported by facilitated diffusion, from the inter-membrane space, through a channel in ATP synthase into the matrix
-The energy of the H+ ions flowing down their concentration gradient is harnessed resulting in the phosphorylation of ADP into ATP by ATP synthase
