12 Respiration Flashcards
Describe the link reaction
1 decarboxylation; A description
2 dehydrogenation / oxidation, (of pyruvate) ; A description
3 reduced NAD produced ;
4 formation of, acetyl coenzyme A / acetyl CoA ;
Describe the features of ATP that make it suitable as the universal energy currency
1 small / water-soluble, so can move around cell ;
2 loss of phosphate / hydrolysis, leads to energy release ;
3 (release energy) immediately / in small packets or
ref. 30.5 kJ (mol-1) ;
4 can be, recycled / regenerated or
ATP 5 ADP + Pi;
5 link between energy-yielding and energy-requiring reactions / AW;
6 high turnover / described ;
7 ref. to ATPase
Outline the roles of NAD and FAD coenzymes
1 hydrogen / electron, carriers ; R hydrogen ions / hydrogen molecules
2 in glycolysis NAD becomes reduced ;
3 (so that) triose phosphate becomes, oxidised / dehydrogenated ;
4 in the link reaction NAD becomes reduced ;
5 (so that) pyruvate becomes, oxidised / dehydrogenated or
for production of acetyl coenzyme A ;
6 in the Krebs cycle both NAD and FAD become reduced ;
7 to regenerate oxaloacetate ;
8 (deliver, hydrogen/H- and e-), to inner mitochondrial membrane / to cristae/ to ETC / for oxidative phosphorylation / for chemiosmosis ;
9 ref. to ATP production ;
10 ref. to recycling of, NAD/FAD;
Outline how yeast carries out anaerobic respiration
1 glycolysis ;
2 glucose to pyruvate ;
3 pyruvate to ethanal by, decarboxylation / COz removal ;
4 ethanal, reduced / hydrogenated, to ethanol ;
5 reduced NAD to NAD; A regeneration of NAD
6 AVP; e.g. ethanol / alcohol, dehydrogenase or pyruvate decarboxylase
Outline the process of glycolysis
1 glycolysis ;
2 phosphorylation of glucose;
3 splitting of fructose (1,6) bi(s)phosphate / AW;
4 (into) two, triose phosphate/ TP ;
5 (TP) oxidised / dehydrogenated, to pyruvate ;
6 net 2 ATP/ 4 ATP, produced ;
7 (2) reduced NAD produced;
Explain why pyruvate enter link reaction only when oxygen is present
1 pyruvate converted to, acetyl group / 2C group / acetyl CoA (in link reaction) ;
2 NAD needed (in link reaction) ;
3 (where) NAD becomes reduced ;
4 reduced NAD goes to ETC;
5 ETC / oxidative phosphorylation, works if oxygen is present or
oxygen is the final electron acceptor;
6 (so) reduced NAD is oxidised / NAD is regenerated ;
Describe how you would carry out an investigation to calculate the effect of substrate concentration on the rate of respiration of yeast in anaerobic conditions using a redox
indicator, such as DCPIP or methylene blue.
1 vary / different / range of, glucose / fructose, concentrations ;
2 control / same, volume of yeast (suspension) ;
3 control / same, volume of glucose (solution) ;
4 control / same, volume / concentration, of indicator (solution) ;
5 control temperature (between 20-45°C) ;
6 oil layer to exclude, air / oxygen ;
7 indicator turns from blue (start / oxidised to colourless (end / reduced :
8 due to, hydrogen atoms / H*/ electrons, from, glycolysis / dehydrogenation / respiration :
9 time how long it takes for colour change OR fix time interval and measure with colorimeter ;
10 repeat experiment ;
11 calculate mean(s) :
12 graph with glucose concentration (on x axis) and, time taken / % absorbance / % transmission / rate (on y) ;
Explain the process of oxidative phosphorylation
1 reduced NAD / reduced FAD, releases hydrogen ;
2 ref. to inner membrane / cristae ;
3 hydrogen splits into H+ and er ;
4 e- passes along, chain of carriers / ETC;
5 energy released used to pump H+ into intermembrane space;
6 high concentration of H+ in intermembrane space / ref. proton gradient ;
7 H+ diffuse back into matrix ;
8 ref. to ATP synthase / stalked particle ;
9 ref. to chemiosmosis;
Explain why the energy yield from respiration in aerobic conditions is much greater than the energy yield from respiration in anaerobic conditions
1 only glycolysis occurs ;
2 (net) 2 ATP produced ;
3 no oxygen as (final) electron acceptor ;
4 (so) pyruvate does not enter mitochondria ;
5 ETC / chemiosmosis / oxidative phosphorylation / Krebs cycle / link reaction, does not occur ;
6 (ETC / chemiosmosis / oxidative phosphorylation) produce most ATP ;
7 pyruvate / ethanal, converted to ethanol ;
8 ethanol still energy-rich /AW ;
Explain why carbohydrates, lipids and proteins have different energy values
1 different substrates have different numbers of, hydrogens / C-H bonds;
2 lipids have (relatively) more, hydrogens / C-H bonds (than carbohydrates or proteins);
3 hydrogens /C-H bonds, located in fatty acid (tails of lipids) ;
4 breakdown / oxidation, of substrate provides hydrogen (atoms)
5 for reduction of, NAD/ FAD ;
6 (reduced, NAD / FAD) provides / releases, hydrogen to ETC;
7 hydrogen (dissociates) into protons and electrons ;
8 ref. to energy used up to set potential gradient
9 (so) more, ATP / energy, from lipids per unit mass (than, carbohydrates / proteins) or lipids, more energy dense / have higher (relative) energy value
Describe how you would carry out an investigation to determine the RQ of germinating barley seeds
1 use respirometer;
2 seeds placed on, mesh/ gauze ;
3 КОН/ NaOH / sodalime, to absorb carbon dioxide ;
4 manometer / capillary tube / syringe ;
5 movement of fluid (in manometer / capillary tube / syringe) = uptake of oxygen ;
6 keep, temperature / air pressure, constant ;
7 measure oxygen uptake after certain time :
8 repeat without KOH / NaOH/sodalime ;
9 difference in manometer readings due to carbon dioxide given out ;
Explain how rice is adapted to grow with its roots submerged in water
1 aerenchyma ;
2 in stem and roots ;
3 help oxygen to, move / diffuse, to roots ;
4 shallow roots ;
5 air (film) trapped on underwater leaves ;
6 fast internode growth ;
7 (modified) growth regulated by, gibberellin / ethene ;
8 anaerobic respiration, underwater / when submerged ;
9 tolerant to high ethanol concentration / high tolerance to ethanol ;
10 ethanol dehydrogenase (switched on in anaerobic conditions) ;
11 AVP ; e.g. growth stops /
carbohydrates conserved /
quiescence,
in short-term (flash) floods
Outline the series of steps that make up the Krebs Cycle
1 oxaloacetate accepts, acetate/ acetyl group/ 2C fragment ;
2 to form citrate ;
3 4C to 6C ;
4 decarboxylation ;
5 CO2 released ;
6 dehydrogenation/ oxidation ;
7 reduced NAD produced ;
8 reduced FAD produced ;
9 ATP produced ;
10 substrate-linked/ substrate-level, phosphorylation ;
11 ref. to intermediate compounds ;
12 enzyme-catalysed reactions ;
13 oxaloacetate regenerated ;
