Respiration Flashcards
Describe how ATP is synthesised in oxidative phosphorylation
Reduced NAD is passed to inner membrane/ cristae
Hydrogen released from reduced NAD
Split into electrons and protons
Electrons pass along electron carriers
Energy gradient
Energy released used to pump protons into intermembrane space
Proton gradient is created
Protons pass through protein channels
ATP synthase produces ATP from ADP and inorganic phosphate
Electron transferred to oxygen
Addition of proton to oxygen to form water
(Oxygen = final electron acceptor)
Outline the need for energy in organisms
Organisms need energy to stay alive ATP - universal energy currency Light energy for photosynthesis Light dependent stage detail Light independent stage detail Chemical energy For anabolic reactions Named reaction e.g. protein synthesis Activation of glucose in glycolysis Active transport Sodium/potassium pump/ movement against a concentration gradient Mechanical energy/ movement
With reference to the events occurring inside of a mitochondrion, explain why a faster use of ATP requires a greater rate of oxygen consumption
- ATP is made in the electron transport chain by oxidative phosphorylation
- oxygen is the final electron acceptor
- occurs in the inner membrane of mitochondrion/ cristae
- transfer of electron between electron carriers provides energy
- energy used to pump hydrogen ions inter intermembrane space
- creates proton gradient
- diffusion of hydrogen ions down their electrochemical gradient causes ATP to be synthesised
- chemiosmosis/ ATP synthase
- if less oxygen consumed then fewer electrons transferred along the chain
Suggest the functions of the DNA and ribosomes in a mitochrondrion
DNA for transcription (codes for mRNA)
Synthesis of respiratory enzymes/ inner membrane proteins
Some parasitic worms live in a mammalian gut where there is no oxygen. Suggest how a tapeworm produces ATP in this environment
- Anaerobic respiration
- substrate level phosphorylation in glycolysis
- at triose phosphate to pyruvate step
- net gain of 2 ATP per glucose
- pyruvate reduced (gains hydrogens from reduced NAD)
- forming lactate
- NAD regenerated
- this allows glycolysis to continue
Outline the process of glycolysis in mammalian organisms
Glucose is phosphorylated by ATP Forms fructose bisphosphate Raises energy level of glucose/ activates Or lowers activation energy of reaction Breaks down to two TP 6C—>2 x 3C Hydrogen atoms removed/ oxidised 2 reduced NAD formed 4 ATP produced (so net gain of 2 ATP) Pyruvate produced Other keywords = substrate level phosphorylation, dehydrogenase, phosphofructokinase/ hexokinase
Compare substrate level phosphorylation to oxidative (Direct phosphorylation of ADP) phosphorylation (ATP produced from
SL phosphorylation and Ox Phosphorylation both use enzymes
SL phosphorylation occurs in cytoplasm whereas oxidative phosphorylation occurs in inner mitochondrial membrane
They both also occur in mitochondria
Channel proteins are involved in oxidative phosphorylation but not in SL phosphorylation
Two examples of anabolic reactions in a mammal that require ATP as an energy source
Make protein
Make disaccharides
Make lipids
Name the type of reaction by which ATP is made in the Krebs cycle
Substrate level phosphorylation
Describe the role of oxygen in aerobic respiration
oxygen is used in oxidative phosphorylation
It acts as the final electron acceptor
It also accepts a proton to form water
It allows the ETC to continue
Suggest why the respirometers were left for 10 minutes before measurements were made
To allow acclimatising
Explain why a control respirometer was used in this investigation
Control eliminates effects of variables other than the independent variable
Explain why there is an increased in rate of respiration when temperature increases
Increased kinetic energy
Enzymes involved so more frequent collisions between enzyme and substrate
Why is ATP an ideal energy currency?
Loss of phosphate leads to energy release
Small packets of energy
Small and water soluble so can move around cell
Immediate energy donor
Link between energy yielding and energy requiring reactions
High turnover
Why do lipids have a higher RQ value than carbohydrates and protein?
More C-H bonds Produces more reduced NAD Produces more ATP per gram More aerobic respiration Fats only broken down aerobically
