Glycolysis 1

Question 1

<p>What is glycolysis?</p>

Answer 1

<p>Biochemical reaction, not involving oxygen, that splits carbohydrates into pyruvic or lactic acid whilst producing ATP</p>

Question 2

<p>What kind of phosphorylation does glyclysis produce ATP through?</p>

Answer 2

<p>Substrate level phosphorylation</p>

Question 3

<p>What is the only way that energy can be made when O₂is not present?</p>

Answer 3

<p>Substrate level phosphorylation</p>

Question 4

<p>Why is glycolysis often the process used to generate energy initially during exercise?</p>

Answer 4

<p>O₂cannot get to the cells quick enough</p>

Question 5

<p>What are the 2 phases of glycolysis?</p>

Answer 5

<p>Preparation phase</p>

<p>Payoff phase</p>

Question 6

<p>What happens during the preparative phase of glycolysis?</p>

Answer 6

<p>Two molecules of glucose-3-phosphate are produced per molecule of glucose</p>

Question 7

<p>What happens during the payoff phase of glycolysis?</p>

Answer 7

<p>ATP is produced</p>

Question 8

<p>What is the net gain of ATP in glycolysis and how is this distributed between the preparative and payoff phases?</p>

Answer 8

<p>2 ATP is used during the preparative phase and 4 ATP is gained during the payoff phase</p>

<p>Net gain of 2 ATP per molecule of glucose</p>

Question 9

<p>How many steps are there in glycolysis?</p>

Answer 9

<p>10</p>

Question 10

<p>How many of the 10 glycolysis steps are irreversible?</p>

Answer 10

<p>3</p>

Question 11

<p>Why are the irreversible steps of glycolysis irreversible?</p>

Answer 11

<p>Delta G during those reactions is to highly negative, too much energy put be required to reverse the reaction</p>

Question 12

<p>What are the 10 steps of glycolysis?</p>

Answer 12

<ol> <li>Phosphorylation of glucose (glucose→ glucose-6-phosphate)</li> <li>Conversion of G-6-P to F-6-P</li> <li>Phosphorylation of F-6-P to F-1,6-bisP</li> <li>Cleavege to F-1,6-bisP</li> <li>Interconversion of triose sugars</li> <li>Oxidation of glyceraldehyde-3-phosphate (G-3-P) to 1,3-bisphosphoglycerate (1,3-bisPG)</li> <li>P transfer from 1,3-bisPG to ADP</li> <li>Conversion of 3-PG to 2-PG</li> <li>Dehydrogenase of 2-PG to phosphoenolpyruvate (PEP)</li> <li>Transfer of P from PEP to ADP, producing pyruvate</li></ol>

Question 13

<p>What is fructose-1,6-bisP broken down to into step 4 of glycolysis?</p>

Answer 13

<p>Glyceraldehyde-3-P or dihydroxyacetone-P</p>

Question 14

<p>What are the 3 irreversible steps of glycolysis?</p>

Answer 14

<p>Step 1 - Phosphorylation of glucose (glucose→ glucose-6-phosphate)</p>

<p>Step 3 - Phosphorylation of F-6-P to F-1,6-bisP</p>

<p>Step 10 - Transfer of P from PEP to ADP, producing pyruvate</p>

Question 15

<p>Why is glucose converted to fructose in step 3?</p>

Answer 15

<p>This lowers the activation energy to proceed due to the negative charges of fructose repelling each other</p>

Question 16

<p>What is the first commited step of glycolysis?</p>

Answer 16

<p>Phosphorylation of F-6-P to F-1,6-bisP because previous intermediates can be used for other pathways but F-1,6bisP is destined for glycolysis</p>

Question 17

<p>What is a difference in the requirments of substrate level phosphorylation compared to oxidative phosphorylation, in terms of enzymes?</p>

Answer 17

<p>Substrate level phosphorylation requires soluble enzymes and chemical intermediates, whereas oxidative phosphorylation involves membrane bound enzymes and gradients of protons</p>

Question 18

What does a diagram of glycolysis look like?

Answer 18

Question 19

<p>Why does NAD⁺need to be regenerated?</p>

Answer 19

<p>It is limited in the cell</p>

Question 20

<p>Where does NAD⁺come from?</p>

Answer 20

<p>Niacin which is an essential vitamin</p>

Question 21

<p>What do all fates of pyruvate do?</p>

Answer 21

<p>Regenerate NAD⁺to replinish what was used during glycolysis</p>

Question 22

<p>What is redox balance?</p>

Answer 22

<p>The replinishment of NAD⁺after glycolysis</p>

Question 23

<p>What are the 3 pathways that pyruvate can take?</p>

Answer 23

<p>Fermentation in yeast to ethanol</p>

<p>Aerobic respiration to CO₂</p>

<p>Fermentation in vigorously contracting muscle cells to lactate</p>

Question 24

What does the reaction of yeast producing ethanol look like?

Answer 24

Question 25

<p>How much pyruvate is produced per molecule of glucose?</p>

Answer 25

<p>2</p>

Question 26

<p>How much lactate can be produced per molecule of pyruvate?</p>

Answer 26

<p>1</p>

Question 27

<p>How much acetyl coenzyme A can be produced per molecule of pyruvate?</p>

Answer 27

<p>1</p>

Question 28

<p>What does pyruvate becoming in the absence of oxygen?</p>

Answer 28

<p>Lactate</p>

Question 29

What does the reaction of pyruvate to lactate look like?

Answer 29

Two pyruvates are converted to two lactic acid molecules

Question 30

<p>What is the Cori cycle?</p>

Answer 30

<p>Metabolic pathway where lactate is produced by anaerobic glycolysis</p>

Question 31

<p>What happens if we exercisevigorously?</p>

Answer 31

<p>Muscles don't recieve O₂fast enough to make ATP by oxidative phosphorylation, instead using substrate level phosphorylation producing lactate</p>

Question 32

<p>What is the fate of lactate that is produced from pyruvate?</p>

Answer 32

<p>Transfered to the liver and converted to glucose through gluconeogenisis</p>

Question 33

<p>Where does glycolysis happen?</p>

Answer 33

<p>In a cells cytoplasm</p>

Question 34

<p>What happens to pyruvate when cells have access to O₂?</p>

Answer 34

<p>Oxidised to form acetyl coenzyme A</p>

Question 35

<p>Where does the reaction of pyruvate to acetyl coenzyme A take place?</p>

Answer 35

<p>In the mitochondria of cells</p>

Question 36

<p>Why can red blood cells only do glycolysis (substrate level phosphorylation)?</p>

Answer 36

<p>They do not have any mitochondria to do oxidative level phosphorylation</p>

Question 37

<p>What is also formed when pyruvate is converted into acetyl coenzyme A?</p>

Answer 37

<p>NADH which later gives up its hydride ion (H^-) in the electron transport chain</p>

Question 38

What does the reaction of pyruvate to acetyl conenzyme A look like?

Answer 38

Pyruvate—three carbons—is converted to acetyl CoA