Respiration Flashcards
What is respiration?
a series of enzyme-catalysed reactions which release chemical energy from organic molecules in order to synthesise ATP
what is decarboxylation?
the removal of a carboxyl group to release Carbon Dioxide
what is dehydrogenation?
the removal of hydrogen
Where does Glycolysis occur?
Cytoplasm
Where does Link reaction occur?
mitochondrial matrix
where does Krebs cycle occur?
mitochondrial matrix
where is the electron transport chain
inner mitochondrial membrane
What are the products of glycolysis of glucose(6C)?
2 * Pyruvate (3C)
2 net ATP and 2 Reduced NAD
How many ATP are used in glycolysis?
2
What happens to pyruvate(3C) in link reaction and what does it form?
Pyruvate(3C) is decarboxylated to form acetate and dehydrogenated to reduce NAD
What does the acetyl group (from decarboxylation of pyruvate) combine with and form?
Acetyl group combines with Coenzyme A to form acetyl CoA(2C)
What does Acetyl CoA(2C)combine with and form in the KRebs Cycle
acetyl CoA(2C) combines with oxaloacetate (OAA)(4C) to form Citrate(6C)
What is regenerated for the link reaction during KRebs Cycle?
Coenzyme A
What happens to citrate (6C) and what does it form?
citrate is decarboxylated to form a-ketoglutarate
in krebs cycle turn between 5C and 4C molecules what is formed?
1 ATP, exothermic energy is released
what do dehydrogenations produce per turn?
3 reduced NAD and 1 reduced FAD
what is dehydrogenation?
removal of hydrogen, usually from an organic molecule
How many ATP is produced for one molecule of glucose in a link reaction?
0 ATP
How many ATP is produced for one molecule of glucose in the Krebs cycle
1 ATP for each pyruvate
so total of 2 per glucose molecule (as pyruvate is produced twice through link reaction of 1 glucose
How many Reduced NAD is produced for one molecule of glucose in Link reaction?
2
1 per cycle, cycle occurs twice per glucose
How many Reduced NAD is produced for one molecule of glucose in Krebs Cycle?
6 Reduced NAD
3 per pyruvate molecule
1 glucose forms 2 pyruvate
How many reduced FAD produced for one molecule of glucose in link reaction?
0
How many Reduced FAD are produced for one molecule of glucose in krebs cycle?
2 reduced FAD
1 per pyruvate
2 pyruvate produced from a glucose molecule
How many carbon dioxide molecules are produced for one molecule of glucose in the link reaction?
2
1 per cycle. cycle occurs twice for one glucose molecule
How many carbon dioxide molecules are produced for one molecule of glucose in the krebs cycle?
4 Carbon dioxide molecules
2 per Pyruvate
2 pyruvate produced from one glucose molecule in link reaction
How many ATP molecules are produced during glycolysis of glucose?
4 ATP molecules produced - 2 used
therefore net 2 molecules
How many reduced NAD molecules are produced in glycolysis of one glucose molecule?
2
How many reduced FAD are produced in glycolysis of one glucose molecule?
0
How many carbon dioxide molecules are produced in glycolysis of one glucose molecule?
0
What do Reduced NAD and FAD carry?
hydrogen (electrons and protons)
Where can the coenzymes reduced NAD And FAD bind?
bind to the proteins of the electron transport chain, and transfer there electrons and protons
What happens when an organism anaerobically expires?
only glycolysis takes place
What happens if only glycolysis occurs in an organism?
there will be a build up of Pyruvate and all of the NAD’s will get reduced and can’t be used again.
Glycolysis will then come to a halt, respiration would stop and the organism would die.
What needs to be made and released to allow glycolysis to continue?
Hydrogen rich intermediates which release oxidised NAD
What is the Mammal intermediate?
Pyruvate is reduced to lactic acid/lactate
What is the yeast intermediate?
pyruvate is decarboxylated to make ethanal/acetaldehyde, and then reduced to make ethanol (and carbon dioxide)
What is yeast anaerobic respiration also called?
fermentation
How can long fatty acid chains be used in respiration?
can be split into 2C fragments which enter the pathway as acetyl coenzyme A (enters Krebs Cycle)
How can glycerol be used in respiration?
converted to a 3C sugar and enters the Krebs cycle
How can proteins be used in respiration?
broken down into amino acids and deaminated (removal of NH2). The remaining molecule is an organic acid which can be fed into the Krebs Cycle
What are obligate aerobes?
organisms that must have oxygen for respiration or they die
What are facultative anaerobes?
yeast and some bacteria prefer to aerobically respire but can respire anaerobically
What are obligate anaerobes?
must respire without oxygen, oxygen kills them
