What is ATP synthesised from?	ADP + inorganic phosphate (P)
Name three biological processes that require the use of ATP	active transport, endocyctosis, DNA replication
Draw a molecule of ATP	Check book
What is a catabolic reaction?	Occurs within a cell. Large molecules are broken into smaller molecules.
What is an analbbolic reaction?	Small molecules are combined into larger molecules
What is glycolysis?	The first stage of respiration, glucose is converted into pyruvate.
What is NAD?	A coenzyme (nicotinamide adenine dinucleotide) Reduced NAD carries protons and electrons to the cristae
What is phosphorylation in glycolysis?	Where glucose has 2 phosphategroups attached to form hexose bisphosphate using 2 molecules of ATP.
What is hexose bisphosphate split into during glycolysis?	2 molecules of triose phosphate
What is triose phosphate converted into during the oxidation stage of glycolysis?	Pyruvate
How many carbons are found in a molecule of pyruvate?	3
Which molecule accepts the hydrogen atoms from triose phosphate when it is oxidised?	NAD
What are the products of glycolysis for every molecule of glucose?	2 x pyruvate, 2 molecules of ATP, two reduced NAD
What is the net gain of ATP in glycolysis?	2 (four are made but two are used)
Why is glycolysis an anaerobic process?	It occurs in the cytoplasm without the need for oxygen
What is the cristae?	the inner highly folded mitochondrial membrane
What is the mitochondrial matrix?	fluid filled inner part of the mitochondria
What is the average length of mitochondrion?	2-5 micromiters
Where does the link reaction occur in the mitochondria?	the mitochondrial matrix
What is the name of the two coenzymes found in the mitochondria?	NAD & FAD
Where is the electron transport chain found in the mitochondria?	The cristae of the inner membrane
What is the name of the enzyme found in the cristae of the enzyme that synthesises ATP?	ATPsynthase
What is decarboxylation?	removal of a carboxyl group from a substrate molecule
What is dehydrogenation?	the removal of a hydrogen atom from a substrate molecule
What is substrate level phosphorylation?	production of ATP from ADP and P during glycolysis and the Krebs cycle
Why is pyruvate said to be decarboxylated and dehydrogenated during the link reaction?	The pyruvate loses a molecule of carbon dioxide and reduces NAD to become acetyl
What does the acetyl group in the link reaction join with before entering the Krebs cycle?	Coenzyme A
Explain how 1 molecule of glucose is formed into two molecules of acetyl coenzyme A	Glycolysis then the link reaction summary
What molecule enters the Krebs cycle?	Acetyl CoA
How many carbons are found in a molecule of acetyl CoA	2
What molecule does acetyl CoA join to in the Krebs cycle?	oxaloacetate
How many carbons does citrate contain?	6
What two molecules combine together to form citrate in the Krebs cycle?	Oxaloacetate and acetyl CoA
What happens to citrate in the Krebs cycle?	It is decarboxylated and dehydrogenated into a 5C compound
What happens to the 5C compound in the Krebs cycle?	It is decarboxylated and dehydrogenated into a 4C compound
Where does substrate level phosphorylation occur in the Krebs cycle?	The 4C molecule combines temporarily with coenzyme A to produce a molecule of ATP
What are the products of one turn of the Krebs cycle?	3 reduced NAD, 1 reduced FAD, 2 molecules of CO2 and 1 molecule of ATP
What is the final stage of aerobic respiration called?	oxidative phosphorylation
Define chemiosmosis	the flow of protons, down their concentration gradient, across a membrane, through channel associated with ATP synthase
What is oxidative phosphorylation?	the formation of ATP using energy released from the ETC and in the presence of oxygen.
Where does oxidative phosphorylation take place?	in the mitochondria
What is the electron transport chain?	A chain of electron carrier proteins that contain an Fe ion. As electrons pass along the chain, some of the enrgy is used to pump protons across the inner mitochondrial membrane.
What is the name of the enzyme embedded in the cristae that is involved in oxidative phosphorylation?	ATP synthase
Which two coenzymes deliver hydrogen atoms to the ETC?	Reduced NAD & reduced FAD
How do reduced NAD & FAD relaese the hydrogen atoms they are carrying at the ETC?	They are reoxidised
What happens to the hydrogen atoms released at the ETC?	They are split into protons and electrons
When electrons are released at the ETC from reduced NAD and FAD, what is their fate?	They are passed along the chain of electron carriers. They are finally accepted by oxygen which helps to form water.
Where are protons pumped into by the ETC?	The intermembrane space
What forms when protons are pumped into the intermembrane space?	A proton gradient
What is the source of potential energy in the intermembrane space?	The proton gradient accumulates and creates a chemiosmotic potential also known as the proton motive force. The energy is used to genertae ATP.
As protons flow from the high concentration inside the intermembrane space, why must they flow through ATP synthase?	The protons cannot easily flow through the lipid bilayer of the mitochondrial membranes.
How does the flow of protons cause ATP to be formed?	The protons cause a conformational change in the ATPsynthase which allows ADP and Pi to combine to form ATP.
What is the final electron acceptor?	oxygen
How is water formed during oxidative phosphorylation?	Oxygen accepts the electrons and combines with protons from chemiosmosis to form water
Which stage of photosynthesis also involves chemiosmosis?	Photophosphorylation in the light dependent reaction
How many ATP can be formed from a molecule of reduced NAD?	3 ATP (2.5)
How many ATP can be formed from a molecule of reduced FAD	2 ATP (1.5)
How many molecules of ATP can be formed from glycolysis by 1 molecule of glucose?	2
How many molecules of ATP can be formed from the link reaction by 1 molecule of glucose?	0
How many molecules of ATP can be formed from the Krebs cycle by 1 molecule of glucose?	2
How many molecules of ATP can be formed from oxidative phosphorylation by 1 molecule of glucose?	28
What is the total yield of ATP from one molecule of glucose during aerobic respiration?	32
Why is the theoretical yield of 32 ATP per glucose molecule rarely achieved?	Some ATP is used, some portons may leak through the mitochondrial membrane
Why is the pH of the intermebrane space lower that the mitochondrial matrix and the cytoplasm?	There is an accumulation of protons.
What are the two metabolic pathways used by eukaryotic cells to reoxidise NAD	Ethanol fermentation and lactate fermentation
Which stage of respiration is the same for both aerobic and anaerobic respiration? Why?	Glycolysis, it occurs in the cytoplasm
In ethanol fermentaion, what enzyme decarboxylates pyruvate into ethanal?	pyruvate decarboxylase
The enzyme pyruvate decarboxylase converts pyruvate into what during ethanol fermentation in yeast?	ethanal
Which enzyme is used to help ethanal accept hydrogen from reduced NAD in ethanol fermentaion in yeast?	ethanol dehydrogenase
Why is yeast described as a faculative anaerobe?	It can respire aerobically or anaerobically depending on the environment
Write out the two steps involved in ethanol fermentation	1. Pyruvate --> Ethanal + CO2; 2. Ethanal + H+ from reduced NAD --> Ethanol
What is the name of the enzyme that allows pyruvate to accept hydrogen from reduced NAD in lactate fermentation	lactate dehydrogenase
Write out the equation for formation of lactate in anaerobic respiration in eukaryotic cells	Pyruvate + H+ from reduced NAD --> lactate
What is the fate of lactate?	It is moved to the liver where it is eitehr converted back into pyruvate or it is recycled to glucose and oxygen
Lactate and ethanol fermentation do not produce any ATP. Suggest how these processes still allow the production of some ATP	Both processes allow glycolysis to continue which has a net gain of 2 ATP
What is a respiratory substrate?	an organic substance that can be oxidised by respiration, releasing energy to make ATP
How can glycerol be used as a respiratory substrate?	It is converted to triose phosphate and then respired
How are fatty acids used as respiratory substrates?	They combine with acetyl Co A and enter the Kreb cycle
How are proteins used as respiratory substrates?	Different amino acids can enter different stages of aerobic respiration e.g. serine can be converted into pyruvate
Which respiratory substrate can be converted into acetate and enter the Krebs cycle via the link reaction?	fatty acids
Which molecule can be deaminated and the rest of the molecule enetrs the Krebs cycle directly?	amino acids
Why do lipids have the highest a mean energy value per gram?	Lipids contain large chains of hydrocarbons which are a source of protons
What is the formula for the respiratory quotient?	CO2 produced/ O2 consumed
What is the RQ value for glucose?	1
What is the RQ value for fatty acids?	0.7
What is the RQ value for proteins?	0.8
What does an RQ value of over 1 suggest?	Anaerobic respiration is taking place
In an investigation into respiration, the RQ value was calculated as 0.82. Suggest which respiratory substrate was being used.	Protein
In an investigation into respiration, the RQ value was calculated as 0.99. Suggest which respiratory substrate was being used.	Glucose
In an investigation into respiration, the RQ value was calculated as 0.70. Suggest which respiratory substrate was being used.	Fatty acids
In an investigation into respiration, the RQ value was found to be 2.3. Suggest what can be deduced from these findings?	Anaerobic respiration has occurred

5.2 - Respiration