Respiration- steps for glucose

Question 1

what is ATP?

Answer 1

-the energy molecule provided by respiration

Question 2

what is the word equation for respiration?

Answer 2

glucose + oxygen = carbon dioxide + water + energy in the form of ATP

Question 3

what is the chemical equation for respiration?

Answer 3

C6H12O6 + 6O2 = 6CO2 + 6H2O + ATP

Question 4

what is a molecule of ATP made up of?

Answer 4

-3 phosphate molecules
-a sugar (ribose)
-and a base (adenine)

Question 5

what type of energy is released in respiration which is stored as ATP?

Answer 5

-chemical energy

Question 6

what does ATP stand for?

Answer 6

-adenosine tri-phosphate

Question 7

what does respiration convert?

Answer 7

-it convert chemical energy stored in glucose into chemical energy stored in ATP

Question 8

how is ATP synthesized?

Answer 8

-it is synthesized from ADP and an inorganic phosphate (Pi) molecule

Question 9

what does ADP stand for?

Answer 9

-adenosine di-phosphate

Question 10

what compound is released when ATP is synthesized?

Answer 10

-a water molecule is released when ADP and Pi are joined together to form ATP

Question 11

when ATP is broken down what is released?
when ATP is synthesized what is needed?

Answer 11

-energy is released
-energy is needed by the body

Question 12

what are 3 processes in the body that require energy>?

Answer 12

-active transport
-glycolysis
-muscle contraction

Question 13

what are the enzymes that catalyse the breakdown of ATP?

Answer 13

-ATP hydrolase enzymes catalyse the breakdown of ATP into ADP +Pi and they use the energy that is released

Question 14

how often does the synthesis and breakdown of ATP occur?

Answer 14

-constantly ATP id being formed and broken down due to the bodies demand for energy

Question 15

what is the process called when ADP and Pi join to form ATP?

Answer 15

-phosphorylation

Question 16

what are the 4 stages of respiration and where do they occur?

Answer 16

-glycolysis- cytoplasm of the cell
-the link reaction- matrix of mitochondria
-the Krebs cycle- matrix of mitochondria
-the electron transport chain- inner membrane of mitochondria

Question 17

which stages of respiration do and do not involve oxygen?

Answer 17

-glycolysis doesn’t require oxygen
-every other step does

Question 18

why do the 4 stages occur in different parts of the cell?

Answer 18

-to keep the metabolites separate

Question 19

what does oxidation, reduction and redox reactions mean?

Answer 19

-oxidation is the addition of oxygen or the removal of hydrogen
-reduction is the addition of hydrogen or the removal of oxygen
-redox reaction is when both oxidation and reduction occur at the same time

Question 20

who many membranes does the mitochondria have and what do they entail?

Answer 20

-double membrane
-outer membrane contains protein channels which let small molecules through
-inner membrane is impermeable and is also highly folded into cristae which gave it a large surface area

Question 21

what is attached to the inner membrane of the mitochondria?

Answer 21

-ATP synthase enzymes are attached in globules to the inner membrane

Question 22

why is it not true to say that respiration turns oxygen into carbon dioxide?

Answer 22

-carbon dioxide is released before oxygen is involved
-what actually happens that glucose is turned into carbon dioxide and oxygen is turned into water

Question 23

what is the goal of glycolysis?

Answer 23

-to turn glucose which is a 6 carbon molecule into a 3 carbon molecule called pyruvate

Question 24

what is the first step of glycolysis (to the split)

Answer 24

-first glucose undergoes phosphorylation which uses 2 molecules of ATP, they are broken down into ADP and Pi, the 2 Pi molecules then join to the glucose which forms a compound called fructose/ hexose biphosphate
-lysis then occurs by the addition of water which causes the fructose biphosphate to split into 2 compounds of Triose phosphate
-these each contain 3 carbons and one phosphate

Question 25

what happens after the split during glycolysis?

Answer 25

-this occurs twice due to the split -a phosphate molecule from the cell joins onto the 3 carbon triose phosphate to form triose biphosphate -the two phosphate molecules then break off the carbons and join ADP to form 2 molecules of ATP ( 4 molecules total because the whole thing happens twice) -a hydrogen molecule then is also released which then binds to NAD which is a hydrogen carrier, this reduced the NAD which forms NADH (2 formed as the process happens twice) -pyruvate is formed as a result (3 carbon molecule) (2 formed total as the process happens twice)

Question 26

what are the products of glycolysis? why is the number of ATP molecules in the equation smaller than what actually was formed?

Answer 26

-glucose forms 2 molecules of pyruvate, 2 molecules of NADH and 2 molecules of ATP -in total 4 molecules of ATO was created however because 2 ATP molecules were used at the beginning of glycolysis, the net total of ATP is 2

Question 27

how does glucose first enter the cytoplasm of the cell to allow glycolysis to occur?

Answer 27

-it enters the cell from the tissue fluid by diffusion

Question 28

what is the main job of the link reaction?

Answer 28

-to convert pyruvate which is a 3 carbon compound into acetylcoenzyme A which is a 2 carbon compound

Question 29

how many times does the link reaction occur and why?

Answer 29

-twice because 2 molecules of pyruvate was created by glycolysis so both have to be broken down into acetylcoenzyme A

Question 30

what are the steps of the link reaction?

Answer 30

-pyruvate loses a carbon dioxide molecule which is known as decarboxylation -it also loses a hydrogen which then reduces its carrier NAD to form NADH -acetylcoenzyme A is formed as a result

Question 31

where does the CO2 diffuse to during the link reaction after decarboxylation?

Answer 31

-the CO2 diffuses into the tissue fluid and then into the blood where it is carried to the lungs to be exhaled

Question 32

what are the products of the link reaction?

Answer 32

2 acetylcoenzyme A + 2 NADH + 2 CO2 -the link reaction occurs twice which is why there are double of each product

Question 33

what is the purpose of the Krebs cycle?

Answer 33

-Acetylcoenzyme A into CO2 and reduced NAD

Question 34

what are the steps of the Krebs cycle?

Answer 34

-oxaloacetate which is a 4 carbon compound is added onto Acetylcoenzyme A which is converted into a 6 carbon compound called Citrate, coenzyme A is lost in this step and goes back to the link reaction -citrate is then broken down by a redox reaction to a 5 carbon compound called oxoglutarate, which released a carbon dioxide molecule and a hydrogen which reduces NAD to form NADH -the oxoglutarate is then converted into a 4 carbon compound called oxaloacetate, during this another molecule of CO2 is released as well as 2 hydrogen molecules which reduced NAD to NADH, it also releases another hydrogen which is carried via FAD to form FADH, finally a molecule of ATP is formed from ADP + Pi

Question 35

how many times does the Krebs cycle occur and why?

Answer 35

-twice because the link reaction occurs twice which creates 2 molecules of Acetylcoenzyme A

Question 36

what are the total number of each product formed by the Krebs Cycle?

Answer 36

--the Krebs cycle happens twice -2 molecules of ATP are created at the end of the breakdown of oxoglutarate -2 molecules of reduced FADH also created at the end of the breakdown of oxoglutarate -4 molecules of CO2 one molecule is released during the breakdown of citrate and one more when oxoglutarate is broken down (4 total as it happens twice) -6 molecules of NADH one molecule is reduced during the breakdown of citrate and two more are reduced during the breakdown of oxoglutarate

Question 37

where does the Krebs cycle occur?

Answer 37

-mitochondrial matrix

Question 38

where does the electron transport chain occur?

Answer 38

-the inner mitochondria -specifically the cristae as they contain the electron carriers

Question 39

what is another name for the electron transport chain?

Answer 39

-oxidative phosphorylation

Question 40

what happens during the electron transport chain/ oxidative phosphorylation?

Answer 40

-the hydrogen atoms from reduced NAD (NADH) are released and split into hydrogen ions and high energy electrons (split into protons and electrons) which release all their energy to form ATP -electrons are carried form one electron carrier to the next which causes them to lose energy, therefore creating ATP for the body to use -this is done by a series of redox reactions -at the end the hydrogen ions and the electrons recombine with oxygen to form water

Question 41

what are the 5 electron carriers called that are involved in oxidative phosphorylation?

Answer 41

-NAD -flavoprotein -FAD -coenzyme Q -cytochromes

Question 42

what is the name of the final electron recipient during oxidative phosphorylation?

Answer 42

-oxygen

Question 43

how many molecules of ATP does NADH and FAD create?

Answer 43

-NAD makes 3 whereas FAD makes 2

Question 44

what is the total number of ATP molecules created by respiration? how many molecules of NADH and FADH are created during the entirety of respiration?

Answer 44

-38 ATP -there are 10 molecules of NADH created during respiration: 2 during glycolysis, 2 during the link reaction and 6 during the Krebs cycle -there are 2 molecules of FADH created during respiration: 2 during the Krebs cycle

Question 45

how many molecules of ATP are created during the first 3 stages of respiration (not the total)?

Answer 45

-4 ATP -2 molecules are created during glycolysis (4 actually made but 2 were used at the start) and 2 more molecules were made during the Krebs cycle

Question 46

why is ATP such a suitable energy source?

Answer 46

-hydrolysis of ATP is a single reaction which releases immediate energy -ATP releases a small manageable amount of energy during energy requiring processes -its a small soluble molecule and so is easily transported throughout the body