Module 1: Lecture 3

Question 1

glycolysis is done in how many reactions?

Answer 1

10

Question 2

what is NADH?

Answer 2

a carrier of electrons and of a hydrogen

Question 3

the energy we got from splitting open and breaking up a glucose molecule is mostly where?

Answer 3

in NADH and/or pyruvate

Question 4

what is the 6 carbon molecule, glucose, broken down to?

Answer 4

two, 3 carbon pyruvates

Question 5

where does the energy used to covert ADP to ATP come from?

Answer 5

some energy from the broken chemical bonds of glucose
- most energy is with the pyruvate

Question 6

what is McArdle disease?

Answer 6

absence of enzyme involved in the first step of glycogen to glucose conversion
- they will have an energy deficency

Question 7

how is glucose stored?

Answer 7

as glycogen in the inclusions in the cytosol part of the cell

Question 8

what cells in our body have more inclusions in the cytosol for glycogen storage?

Answer 8

liver and muscle cells

Question 9

where does pyruvate go to after glycolysis?

Answer 9

the mitochondrial matrix

Question 10

why do we want cristae for increasing surface area?

Answer 10

electron transport chain proteins need to go in there for production of ATP

Question 11

(2) pyruvate is decarboxylated, and turned into? (3 –>2 carbon molecule)

Answer 11

Acetyl-CoA x 2

waste: CO2 x 2
(O2 is coming from glucose and C is coming from pyruvate)

Question 12

what happens in the TCA cycle?

Answer 12

acetyl CoA is added to a 4C molecule using an enzyme to make a 6Carbon molecule (citrate/citric acid)

Question 13

how many steps in the TCA?

Answer 13

8

Question 14

how many NADH do we generate in the TCA cycle per glucose molecules?

Answer 14

6

Question 15

why is it called the Krebs cycle?

Answer 15

Krebs was the scientist who discovered it

Question 16

why is it called the citric acid cycle or the TCA?

Answer 16

Acetyl-CoA enters the cycle by combining with a molecule called oxaloacetate (4 carbon) to make a 6 carbon molecule which is then catalyzed by an enzyme to generate a molecule called citric. Citric has 3 carboxylic groups in it, which makes it a tricarboxylic acid (TCA)

Question 17

how many NADH are produced in the TCA per one glucose molecule?

Answer 17

2

Question 18

how many FADH2 do we make per TCA cycle? per glucose?

Answer 18

1 per TCA cycle
2 per glucose

Question 19

how many ATP per TCA cycle?

Answer 19

1 per TCA cycle
2 per glucose

Question 20

what are the hydrogen carrier molecules?

Answer 20

Nicotinamide Adenine Dinucleotide (NAD+) and
Flavine Adenine Dinucleotide (FAD)
–> NADH and FADH2 (once hydrogens are added to both)

Question 21

on average, NADH produces how much ATP in the ETC?

Answer 21

2-3 ATP (2.5 avg)

Question 22

the way ATP is made in glycolysis is which ATP production system?

Answer 22

substrate level phosphorylation

Question 23

other than ADP + P –> ATP, what is another example of substrate level phosphorylation?

Answer 23

GTP –> GDP + P –> ADP + P –> ATP

ADP + GTP <–> ATP + GDP

Question 24

how many net ATP are created per one glucose molecule in glycolysis and the TCA? (together)

Answer 24

4

Question 25

after TCA is complete, where is all the energy?

Answer 25

in the NADH and FADH2 (in the hydrogen)

Question 26

where does the ETC happen?

Answer 26

inter membrane space

Question 27

after TCA, the series of electron carrier molecules are going to be where?

Answer 27

on the inner membrane of mitochondria

Question 28

how is most ATP produced?

Answer 28

from the NADH and FADH2 in the ETC

Question 29

as the electrons are passed through each complex, they are losing energy. where is this energy going and how is it being used?

Answer 29

it is going into the complexes to allow them to change shape.

Question 30

what happens when the last complex has the electron?

Answer 30

it has no where to pass it to, so it holds it. then the second last complex has an electron and has no where to pass it, so it holds it. this continues to make a backlog.

Question 31

what is the final electron acceptor in ETC? When the electron is accepted, what does the acceptor turn into?

Answer 31

oxygen. then turns into H2O

Question 32

If we stop breathing, where does respiration stop?

Answer 32

pyruvate decarboxylation

Question 33

what is the average ATP made in respiration per one glucose molecule?

Answer 33

32 ATP

Question 34

how many ATP does FADH2 make on average?

Answer 34

1.5 ATP

Question 35

how many complexes are in the ETC?

Answer 35

4

Question 36

what is a complex in the ETC?

Answer 36

a complex of molecules (proteins or not) that work together to carry the high energy electrons and carry them along

Question 37

which complex does not reach the entire inner mitochondrial membrane all the way through?

Answer 37

the second complex

Question 38

why does the second complex not reach through the entire inner mitochondrial membrane?

Answer 38

because the oxidation of FADH2 to FAD at complex II releases less energy than the oxidation of NADH to NAD+ at complex I

Question 39

once complex 1 turns NADH into NAD+, the H+ is transported through the complex to where?

Answer 39

the intermembrane space

Question 40

can ions travel across the membrane by itself? why?

Answer 40

no. because they are charged and are polar (water loving). the plasma membrane and other membranes are made of phospholipids which is lipids. water and lipids cannot be mixed. - ions cannot cross the membrane because the membrane is hydrophobic and ions are polar (water loving) - they are trapped until a channel(complex one) lets them in and out

Question 41

the high energy electron from the NADH in complex one goes where after complex one?

Answer 41

complex 3, then 4

Question 42

where is the only place that FADH2 can give its electrons?

Answer 42

complex 2

Question 43

why does FADH2 generate less ATP than NADH?

Answer 43

because it moves less hydrogen ions

Question 44

what is ATP synthase?

Answer 44

a complex protein made up of multiple subunits and its job is to generate ATP.

Question 45

how does ATP synthase generate ATP?

Answer 45

uses a gradient of hydrogen ions that are concentrated in the intermembrane space

Question 46

how does hydrogen end up in the intermembrane space?

Answer 46

through the complexes 1, 3 and 4

Question 47

what happens in ATP synthase for it to make chemical energy in the form of ATP?

Answer 47

a mechanical turning of the protein complex (rotates to turn ADP into ATP) - mechanical energy will be put in the phosphate group

Question 48

what is the process of ATP synthase generating ATP called?

Answer 48

Chemiosmosis

Question 49

how many NADH in cellular respiration total? how many FADH2? How much ATP does each generate?

Answer 49

10 NADH (x 2.5 = 25 ATP) 2 FADH2 (x1.5 = 3 ATP)

Question 50

if no oxygen is available, what happens to the pyruvate in glycolysis? (anaerobic)

Answer 50

pyruvate is converted into lactate with the use of hydrogen from NADH.

Question 51

when we do not consume any glucose, how does our body produce energy?

Answer 51

uses fatty acids and proteins (only if necessary) instead but they enter at the Acetyl CoA step