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Physiology - Respiration

	Where in the cell does the glucose come from for glycolysis?
	from simple sugars in the vacuole or breakdown of starch in amyloplasts

	In what form is the glucose stored in these places?
	simple sugars in the vacuole starch in amyloplasts

	Where does glycolysis occur?
	in the cytosol

	What happens to glucose in glycolysis - what is the end product and how much oxidation has occurred?
	It is split into two three-carbon sugars and each gains a single oxygen to form pyruvate.

	How much of the available energy has been liberated?
	only about one-sixth

	What goes into the tricarboxylic acid (TCA) acycle and what comes out?
	a two carbon acid (acetate) and NAD in C02 and NADH out

	What is the link between glycolysis and the TCA cycle?
	Pyruvate is converted to acetate (strictly acetyl-coenzyme A).

	Where does the cycle occur?
	mitochondria

	What important energy transformation pathway is linked to the TCA cycle?
	electron transport or cytochrome chain converting NADH, ADP, phosphate and oxygen to ATP, water and NAD

	How much of the energy in glucose has been made available by glycolysis and the TCA cycle for further reactions?
	about 38%

	What fraction of this energy is released in the cycle?
	about five-sixths

	What happens to the products of glycolysis when there is no oxygen?
	pyruvate and NADH are converted to CO2, ethanol and NAD

	In order to begin to get energy what pathway would glucose need to enter: Krebs cycle glycolysis electron transport chain
	Not just yet - all of the compounds in the Krebs Cycle are organic acids.   Yes, glycolysis means "sugar splitting" so this is the place to start.   This is where the energy will come out, but we have a long way to go!

	The first steps in glycolysis convert six carbon sugars into: phosphorylated intermediates oxidised compounds three carbon sugars
	Yes, we have to use energy in the form of ATP to make sugar phosphates before we can begin to get energy out.   No it's too soon to start oxidizing. There are enzymes that oxidize sugars but they do not yield energy.   Wait a moment.

	The six-carbon sugar phosphate is converted to: tricarboxylic acid oxidized compounds three carbon sugar phosphates
	These acids are used in the Krebs Cycle but not in glycolysis.   Not just yet.   Yes, this is the splitting process that gives glycolysis its name.

	In the final steps of glycolysis: pyruvate and ADP are formed alcohol and ATP are formed pyruvate and ATP are formed
	ATP was used and ADP released early on, but it is time for pay back.   Not under normal circumstances. (only in the absence of oxygen)   .Yes, in addition to pyruvate we get 4 ATP (but 2 were used earlier) and 2 NADH for every glucose entering glycolysis.

	The pyruvate from glycolysis is converted to: CO2 and alcohol CO2 and acetate citric acid
	Not under normal circumstances. (only in the absence of oxygen)   Strictly speaking acetyl coenzyme A is the product when CO2 is split off the pyruvate molecule.   Not directly; citric acid will be made later in the Krebs Cycle

	Entering the Krebs cycle, acetate (or acetyl CoA) is combined with: a four carbon acid to make a six carbon acid a three carbon acid to make a six carbon acid a five carbon acid to make a seven carbon acid
	Yes oxaloacetate has four carbons and acetate has two, so they combine to make citric acid which has six.   Acetate has two carbons so this does not add up.   Another name for the Krebs cycle is the "citric acid cycle" and citric acid has six carbons.

	A complete turn of the Krebs Cycle liberates: three CO2 two CO2 four CO2
	Two carbons entered with acetate so this would leave one short.   Yes two carbons entered with acetate and two are released to get back to the start.   Two carbons entered with acetate so this would leave two short.

	The Krebs cycle also generates: NADH (and ATP) NAD (and ATP) ATP
	Yes in addition to a little ATP, most of the energy is transferred to NADH   NAD is the oxidized form; the cycle yields reducing power as carbon compounds are oxidized.   OK, some ATP is made directly in the cycle but this is not the main product.

	Oxidation of NADH results in: production of CO2 electron flow to O2 electron flow from O2
	No, that occurred in the Krebs Cycle and we are done with CO2 at this point.   Yes, along with H+, electrons and O2 make water the final product.   OK, some ATP is made directly in the cycle but this is not the main product..

	Electron flow is coupled to: ATP production O2 production H+ transport
	Not directly.   O2 is consumed, not produced. Yes, the accumulation of H+ is then used to drive ATP formation for the final energy yield.

	The reduced nucleotide (NADPH) and ATP are used to convert: RuBP and CO2 to PGA 3 carbon sugar to 6 carbon sugar PGA to 3 carbon sugar
	his is the reaction catalyzed by Rubisco. It does not involve reduction or phosphorylation.   This happens by reversing the early reactions of glycolysis and does not involve reduction or ATP consumption.   Yes, reducing power and ATP are necessary to produce sugar in this way.

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