p2: respirATION Flashcards
glucose is not suitable as an immediate energy source in cells. yhe energy released is used to form ATP which is an immediate energy source.
why is glucose not used directly?
- glucose produces too much energy (heat) in a cell
- enzymes could denature as a result
how is mitochondria adapted to its function?
- many cristae to increase SA for ETC and ATP synthase
- large SA:V
- short diffusion pathway
- aqueous matrix solution
name the different stages of aerobic respiration
- glycolysis (cytoplasm)
- link reaction (matrix of mitochondria)
- krebs cycle
- electron transport chain
the mitochondria in the muscles contain many cristae. explain the advantage of this.
- large SA for ETC/ oxidative phosphorylation
- provides more ATP for muscle contraction
substrate level phosphorylation
ATP directly generated through energy released via RP reactions
- occurs in glycolysis and krebs cycle
oxidative phosphorylation
- ATP generated from chemical energy released when NADH2/FADH2 oxidised at ETC
describe the process of glycolysis
- phosphorylation of glucose using ATP
- oxidation of triose phosphate to pyruvate
- net gain of ATP
- NADH
- ATP produced by substrate level of phosphorylation
describe how oxidation takes place in glycolysis and in the krebs cycle
- removal of hydrogen
- by dehydrogenases
- reduced NAD formed
- in krebs cycle, FAD as well
link reaction:
- occurs twice for one glucose
- pyruvate actively transported into matrix
- converted to acetyl co A
- no ATP production
- CO2 also produced
krebs cycle
- series of REDOX reactions in mitochondrial matrix
- 2c acetyl co A combines with a 4C molecule to form a 6C compound
- 6C compound loses CO2 and Hydrogen to form a 4C compound and 1 ATP
water is a waste product in aerobic respiration. describe how water is formed at the end of aerobic respiration.
- oxygen is final electron acceptor
- combines with electrons and protons to form water
explain how the amount of ATP is increased by reactions in the mitochondria
- oxidation of electrons and Hydrogen ions from pyruvate
- acetyl coA
- ATP produced in krebs cycle
- NADH AND reduced FAD produced
- in matrix of mitochondria
- electrons fed into ETC
- energy released
- protons move into intermembrane space
- ADP + Pi
- ATP synthase
describe the role of the coenzymes and carrier proteins in the synthesis of ATP
OR
describe the events of oxidative phosphorylation
- NAD AND FAD reduced
- electrons transferred from coenzyme to coenzyme
- ETC on cristae of inner membrane
- energy released via series of REDOX reactions
- oxygen final electron acceptor
- energy released used to pump protons into intermembrane space forming an electrochemical gradient
- protons flow through ATP synthase to produce ATP from ADP + Pi
describe how ATP is made in the mitochondria
- ATP produced in Krebs Cycle
- krebs cycle produces reduced NAD/ FAD
- electrons released from reduced NAD/FAD
- pass through ETC via series of REDOX
describe the events of oxidative phosphorylation
- NAD and FAD reduced
- ETC on cristae of mitochondria
- H+ ions transferred from coenzyme to coenzyme
- H+ ions pumped into intermembrane space
- energy released as electrons passed via ETC
- H+ flow through ATP ysnthase
- energu used to synthesise ATP from ADP and Pi
Which stages of aerobic respiration produce CO2?
- link
- krebs
Which stages of aerobic respiration is NAD reduced?
- glycolysis
- link
- krebs
alternative respiratory substances
LIPIDS
- hydrolysed to glycerol and FA
- glycerol phosphorylated and converted to triose phosphate entering glycolysis and krebs
- FA converted to Acetyl coA
- oxidation of FA reduced NAD and FAD to be used in oxidative phosphorylation of ATP
PROTEINS
- NH2 groups removed in liver cells
- forms keto acid
- enter pathway at diff stages
- 3c into pyruvate
- 4c and 5c into krebs cycle
anaerobic respiration
- link, krebs and ETC stop, no O2 to act as final electron acceptor
- glycolysis doesnt require oxygen, so continues
- NAD needs to be generated for glycolysis to continue
- H from reduced NAD accepted by pyruvate (rather than passing through ETC)
- pyruvate reduced to lactate in animals and ethanol and CO2 in plants
respirometers
- O2 use for aerobic RP
- reduces volume of oxygen in tube, reducing pressure
- solution absorbs CO2 released by animal/plant
- higher to lower pressure
- measure time taken
describe how you would measure the rate of respiration in a respirometer
- measure distance ink moves
- over a fixed period of time
- volume and diameter of tube
give two reasons why the respirometer was left for 10 minutes when it was first placed in thw water bath
- equilibrium reached
- allows for expansion in apparatus
- allows respiration of seeds to stabilise
in many mammals, uncoupling proteins helps to maintain a constant body temperature during hibernation. suggest and explain how.
- allows passage of protons
- energy released as heat
the mitochondria in muscles contain many cristae. explain the advantage of this.
- larger SA for ETC
- provides more ATP for contraction
explain why a log scale is used to record the number of bacteria
- large difference in numbers
- exponential numbers
explaining why converting pyruvate to lactate allows the continued production of ATP by anaerobic respiration
- regenerates NAD
- so glycolysis continues
malonate inhibits a reaction in the krebs cycle. explain why malonate would decreate the uptake of oxygen in respiring cells.
- less NAD
- oxygen is final electron acceptor.
