5A Respiration Flashcards
Where does the reactions in aerobic resp take place
Mitochondria
What is the difference and similarity between aerobic and anaerobic respiration
Aerobically with oxygen and anaerobically without
Both produce ATP and start with glycolysis
What is a coenzyme
molecule that aids the function of an enzyme by transferring a chemical group from one molecule to another
what are the coenzymes used in respiration
NAD, COENZYME A, FAD
What do NAD and FAD do?
They transfer hydrogen from one molecule to another so they can reduce and oxidise a molecule
What is the role of coenzyme A
Transfers acetate between molecules
What are the 4 stages in aerobic respiration
Glycolysis
Link
Krebs
Oxidative Phosphorylation
What reaction takes place in the cytoplasm
Glycolysis
What reaction takes place in the mitochondria
Link
Krebs
Oxidative Phosphorylation
What are the respiratory substrates used in aerobic respiration
Glucose
Fatty Acids
Amino acids
Which steps are in the anaerobic respiration
Only glycolysis
What happens in the first stage of aerobic respiration
- PHOSPHORYLATION
- glucose phosphorylated using a phosphate from ATP
- creates 1 molecule of glucose phosphate and 1 ADP
- ATP forms another phosphate –> hexose bisphosphate
- hexose bisphosphate split into 2molecules of Triose phosphate - OXIDATION
- TP oxidised forming pyruvate
- NAD collects hydrogen forming 2 red nad
What are the products of glycolysis and where does it go
2 RED NAD –> oxidative phosphorylation
2 pyruvate –> mitochondrial matrix for link
2ATP –> used for energy
What are the products of glycolysis - ANAEROBIC
Using red nad
- ethanol via alcohol fermentation (pyruvate > ethanal > ethanol) —- PLANTS AND YEAST
- lactate via lactate fermentation —- ANIMAL CELLS AND BACTERIA
How can glycolysis still continue in anaerobic resp
The production of lactate or ethanol regenerates oxidised NAD so small amount of ATP can be still be produced
What happens in the second stage of aerobic respiration?
- Pyruvate is decarboxylated so one carbon atom removed in the form of CO2
- Simultaneously pyruvate is oxidised to form acetate
- NAD reduced to RED NAD
- Acetate combines with coenzyme A to form ACETYLECOA
How many times does the link reaction occur per glucose molecule
2 pyruvate molecules are made for every glucose molecule that enters glycolysis so the link and krebs occur twice for every glucose molecule
What are the products of the link reaction and where do they go
2 Acetyl coenzyme A - krebs cycle
2 Carbon dioxide - released as waste
2 Reduced NAD - to oxidative phosphorylation
What are the stages of the 3rd step in aerobic respiration
- Formation of 6c compound
- Acetyl CoA combines with a 4C Oxaloacetate to form a 6C Citrate
- coenzyme A returns to link reaction - Formation of a 5c combound
- Citrate is converted to a 5C molecule through decarboxylation
- Dehydrogenation also occurs
- reduced nad produced - Regeneration of oxaloacetate
- 5c converted to 4c
- decarboxylation and dehydrogenation occur producing one molecule of reduced FAD and 2 of reduced NAD
- atp produced by transferring a phosphate to adp ( substrate level phosphorylation)
What are the products of krebs and where does it go
- 1 COA - reused
- Oxaloacetate - regenerated for next krebs
- 2 Carbon dioxide - released as waste
- 1ATP - energy
- 3 RED NAD - oxidative phosphorylation
- 1 RED FAD - oxidative phosphorylation
What is the steps to the last stage of aerobic resp
- Hydrogen atoms are released from red NAD and FAD splitting into protons and electrons
- Electrons move down ETC losing energy
- Energy used by electron carriers to pump protons from mitochondrial matrix into inter membrane space
- Concentration of protons higher in inter membrane forming electrochemical gradient
- Protons move down back into matrix via ATP synthase driving formation of ATP - CHEMIOSMOSIS
- At the end the protons, electrons and oxygen combine to form water as oxygen is the final electron acceptor
What is the impact of mitochondria diseases
- ATP production
- Functioning of proteins in o.p or krebs reducing ATP
- Anaerobic increases to make up for ATP shortage so lactate produced
- Muscle weakness and fatigue
- Lactate diffuses into blood
