Chapter 18: Respiration Flashcards
Why do plants animals and microorganisms need to respire ?
Plants animals and microorganisms need to respire so that they have energy (provided by the breakdown of ATP) for essential energy requiring processes like
cell division, active transport, exocytosis and endocytosis, protein synthesis
What does the structure of a mitochondria look and how does it relate to its function (matrix)
matrix- contains the enzymes required to catalyse stages of respiration and contains mitochondrial DNA to make these enzymes
What does the structure of a mitochondria look and how does it relate to its function ( inner membrane)
inner membrane- holds different types of proteins e.g. electron carrier + ATP synthase that facilitate respiration
What does the structure of a mitochondria look and how does it relate to its function (cristae)
cristae- folds that increase SA for inner membrane to hold more electron carriers and enzymes (increase rate of respiration)
What does the structure of a mitochondria look and how does it relate to its function (inter-membrane space)
Inter membrane space- protons are pumped here creating conc gradient (for ATP synthesis)
What does the structure of a mitochondria look and how does it relate to its function (outer membrane)
Outer membrane - function of compartmentalisation keeping mitochondria separate from the cytoplasm
Outline the stages of glycolysis
Stage 1: glucose is phosphorylated by 2 ATP molecules to form hexose bisphosphate (creates x2 ADP)
Stage 2: hexose bisphosphate is split into X2 triose phosphate molecules which are then each phosphorylated by an inorganic phosphate group (from the cytoplasm) forming X2 triose bisphosphate
Stage 3: each triose bisphosphate molecule has 2 ADP remove 2 phosphate groups from it (forming 2 ATP) and a hydrogen atom which is removed by NAD forming reduced NAD
Stage 4: x2 pyruvate molecules are now produced
Where does glycolysis happen
in the cytoplasm
What are the products of glycolysis
x2 ATP, x2 reduced NAD and x2 pyruvate molecules
What is substrate level phosphorylation
the process by which ATP is produced without the use of an electron transport chain and ATP synthase and ADP is simply phosphorylated by an unstable intermediate to form ATP
Describe the stages of the link reaction
Stage 1: NAD removes a hydrogen ion from pyruvate forming reduced NAD
Stage 2: Pyruvate is then decarboxylated (co2 is given out) forming a 2 carbon acetyl group
stage 3: Acetyl group combines with Coenzyme A to form Acetyl coenzyme A
How many times does the link reaction occur and why?
It occurs twice because of the two pyruvate molecules formed by glycolysis
Where does the link reaction happen?
in the mitochondrial matrix
How does pyruvate enter the mitochondrial matrix
by active transport
What are the products of the link reaction
1 reduced NAD, 1 CO2 and 1 Acetyl coenzyme A
What are the stages of the Krebs cycle
Stage 1: the acetyl group from acetyl CoA is delivered to the krebs cycle combining with the four carbon oxaloacetate to form citrate
stage 2: the citrate molecule undergoes 2 decarboxylation’s and then forms one ATP (via substrate level phosphorylation) and goes through dehydrogenation all throughout
DeNa DeNa AFa Na
Stage 3: eventually oxcaloacetate is reformed
what is the importance of coenzymes in respiration
they are required to transfer electrons and protons as well as functional groups between many enzyme catalysed reactions
