Lecture 3

Question 1

After NADH is produced from the process of glycolysis, which statement does not describe how can it be used within the cell?
In the context of the question the answer is wrong but study this because it is described for what can be used, so anything that doesn’t describe this would be right.
Aerobic Respiration, Fermentation → Acetaldehyde, Lactic Acid & Ethanol

Answer 1

In the context of the question the answer is wrong but study this because it is described for what can be used, so anything that doesn’t describe this would be right.

Aerobic Respiration, Fermentation → Acetaldehyde, Lactic Acid & Ethanol

Question 2

Once glycolysis is complete, the first step within the first process of aerobic respiration is the oxidation of pyruvate. Where in the mitochondria does this process take place?

Answer 2

done in the intermembrane space(in between outer membrane and matrix membrane)

Question 3

Once glycolysis is complete, the first step within the first process of aerobic respiration is the oxidation of pyruvate. What is the equation of this process?

Answer 3

Pyruvate + NAD+ +CoA → Acetyl - CoA + NADH
(i.e. know the reactants and products we discussed and the equation which was on the board)

Question 4

After pyruvate oxidation is complete, acetyl Co-A is produced. Which statement describes a way acetyl-CoA can be used within your body?

Answer 4

Two main ways, energy storage and the krebs cycle
(we discussed two main ways)

Question 5

After pyruvate oxidation is complete, acetyl Co-A is produced. Acetyl Co-A can then be used within your cells in two main ways. ______________ takes place if the ATP level is high within the cell and ______________ takes place if the ATP level is low within your cell. Fill in the blanks

Answer 5

1. Energy/Fat Storage 2. Krebs Cycle

Question 6

Where within the mitochondria does the Krebs cycle (the citric acid cycle) take place?

Answer 6

Mitochondrial matrix

Question 7

Which statement describes any steps, reactants, or products of segment A of the Krebs cycle?
Step: carboxylating adding carbons (only time you’ll be adding carbons)
Explanation: acetyl CoA (coenzyme and two carbons, created during pyruvate oxidation) attached to 4 carbon molecules called oxaloacetate (left over from previous cycle since krebs are continuous). CoA kickstarts the program. Once the molecules are together in the Matrix. CoA will detach and go back to pyruvate oxidation to be reloaded. You’re then left with a 6 carbon molecule, called citrate.
Products and reactant:

Helpful tip: 2 + 4 = 6

Answer 7

Step: carboxylating adding carbons (only time you’ll be adding carbons)

Explanation: acetyl CoA (coenzyme and two carbons, created during pyruvate oxidation) attached to 4 carbon molecules called oxaloacetate (left over from previous cycle since krebs are continuous). CoA kickstarts the program. Once the molecules are together in the Matrix. CoA will detach and go back to pyruvate oxidation to be reloaded. You’re then left with a 6 carbon molecule, called citrate.
Products and reactant: 2 CoA (Acetyl-CoA) 4 carbon molecule (oxaloacetate) + 4 carbon molecule (oxaloacetate) = 6 carbon molecule (citrate)
Helpful tip: 2 + 4 = 6

Question 8

Which statement describes any steps, reactants, or products of segment B of the Krebs cycle?

Answer 8

Segment B: Once citrate is created it’s ready to be broken down.
Steps: only time in the Krebs Cycle that ATP is being produced

i. First step: one of the carbons will be removed and attached to oxygen and you’ll
be left with carbon dioxide (remember: oxygen is there because the whole
process requires oxygen). ETC When you remove stuff (oxidize) Hydrogen is
released so it bonds with NAD+ and forms NADH (goes to ). Last thing left is a
5 carbon molecule because 1 was broken off. 6 -1 = 5

ii. Second Step: Basically the same thing happens again. Another carbon is broken
off, what was once citrate, then carbon dioxide gets created. Then again NADH
gets created. And because you removed another carbon you’re left with a 4
carbon molecule. 5 - 1 = 4

iii. Third Step: Main stuff that happens to Carbon, preparing a molecule for segment
C. You are creating a tiny bit of ATP, because you take the 4 carbon molecules,
which at one point had phosphates, and you’re removing those phosphates to
create very little ATP. Once it loses the phosphates it’s ready for segment C.

decarboxylation: taking carbons away from a molecule (happens in this
segment and pyruvate oxidation 3 carbons → 2 carbon)
dehydrogenase: removing hydron (hydrogating would be opposite)

Question 9

Which statement describes any steps, reactants, or products of segment C of the Krebs cycle?

Answer 9

Steps: you have a 4 carbon molecule, the end product of the other, mainly just carbon since phosphates were removed. So it’ll be oxidized (removing some hydrogens). It stays 4 carbons the entire time, but you are taking hydrogens off and creating some double bonds instead. FADH2 is created alongside NADH, because the hydrogens are removed NAD and FAD are reduced. Will end with 4 carbon molecules, no decarboxylation. To create energy FADH and NADH are sent to ETC

Products and Reactants: Acetyl - CoA → 2CO2 + 2ATP + 3NADH +FADH2 +Acetyl CoA

Question 10

Where within the mitochondria does the ETC (electron transport chain) take place?

Answer 10

Inner mitochondrial membrane

Question 11

What is the proper order of the enzymes and carriers used within the electron transport chain?

Answer 11

NADH Dehydrogenase → Ubiquinone (Q) → BC1 Complex → Cytochrome c → Cytochrome Oxidase

Question 12

The electron transport chain is an area the accepts the electrons transferred within the mitochondria that consist of a series of membrane-associated proteins. What is the function of NADH dehydrogenase within the ETC?

Answer 12

first enzyme used. NADH is put in an enzyme, removes its hydrogen and becomes NAD+. And the Hydrogen will go to an area where it’ll drive a gradient that eventually powers the pump. When you do this because it’s being broken, energy is simultaneously being released, which allows you to go to the next step

Question 13

The electron transport chain is an area the accepts the electrons transferred within the mitochondria that consist of a series of membrane-associated proteins. What is the function of Ubiquinone (Q) within the ETC?

Answer 13

carrier that passes the electrons along the electron chain. The electron will power the chain and make it function. The name is derived from this because you are transferring electrons as they’re simultaneously being created from broken bonds. This will just carry electrons along.

Question 14

The electron transport chain is an area the accepts the electrons transferred within the mitochondria that consist of a series of membrane-associated proteins. What is the function of the BC1 complex within the ETC?

Answer 14

Operates as a proton pump driving protons across the membrane. The pump is powered by the electrons that are continuously removed, when NADH and FADH2 are being oxidized (basically gaining energy from that process). Only job is to drive them across the membrane to have a high concentration, because you are trying to build that high concentration gradient.

Question 15

The electron transport chain is an area the accepts the electrons transferred within the mitochondria that consist of a series of membrane-associated proteins. What is the function of Cytochrome c within the ETC?

Answer 15

Another carrier that moves electrons along the chain. The same thing as Ubiquinone, just know the order of each step.

Question 16

The electron transport chain is an area the accepts the electrons transferred within the mitochondria that consist of a series of membrane-associated proteins. What is the function of Cytochrome oxidase within the ETC?

Answer 16

Hydrogen and Oxygen combine to form water. Oxygen is the final electron acceptor, so it’ll take any leftover hydrogens you have to form water. Don’t want a high amount of oxygen in the mitochondrial matrix, you want them in a high amount in the intermembrane space, so basically taking unwanted hydrogens from the matrix and crating water. This allows you to have a high concentration gradient in the intermembrane space.

Question 17

Which statement accurately describes how the ATP is produced at the end of the ETC (know ALL information we discussed about the proton gradient and how it works)?

Answer 17

a. By the time you get to this step you have an immense amount of hydrogens inside that membrane. On the other side you have a very small amount on the other side regardless of the fact that hydrogens want to cross (because they can travel through easily).

b. The hydrogen comes in through the pump, being turned like a turbine, to create ATP, driven also by a proton gradient. So when the concentration gradient of protons in the intermembrane space is too high they go to an area of low concentration in the matrix and it’ll power this process. It’s a passive reaction forming this, again you don’t want to use energy to create it.

c. ATP Synthase: Enzyme used to create ATP. Powered by the concentration gradient. Means you are synthesizing ATP.

Question 18

What occurs during the process of chemiosmosis?

Answer 18

Producing ATP

Question 19

The electron transport chain is an area the accepts the electrons transferred within the mitochondria that consist of a series of membrane-associated proteins. What is the function of ATP synthase within the ETC?

Answer 19

Enzyme used to create ATP. Powered by the concentration gradient. Means you are synthesizing ATP.

Question 20

What is the theoretical and actual yield of ATP produced by aerobic respiration in eukaryotes?

Answer 20

36 and 30

Question 21

Why is the actual yield of ATP produced during aerobic respiration less than the theoretical yield which should occur? (know the two reasons we discussed in class)

Answer 21

There is leaking in the inner mitochondrial matrix and it allows all the hydrogens to travel through the synthase. Because some just enter the matrix naturally, they want to go from high to low concentration (proton gradient).

Question 22

Due to varying reasonings discussed in class, aerobic respiration only uses ___________ (percent) of energy within one original glucose molecule. Fill in the blank.

Answer 22

32%

Question 23

Aerobic respiration has different control points along its enzymatic pathway to not allow it to continue unless needed. One of the first control points occurs during glycolysis using the enzyme called phosphofructokinase. What things occurring in your cell can turn this enzymes on and off? (know all the conditions we discussed in class)
Phosphofructokinase: this enzyme will catalyze the conversion of fructose phosphate (glucose + phosphate), will turn it into fructose diphosphate (2). This is the enzyme responsible for attaching phosphates at certain parts of the cycle, then kick-starting glycolysis.
High levels of ADP → process turns on (eans you want to create ATP)
High ATP present → this will stay off (can only hold so much)

Answer 23

Phosphofructokinase: this enzyme will catalyze the conversion of fructose phosphate (glucose + phosphate), will turn it into fructose diphosphate (2). This is the enzyme responsible for attaching phosphates at certain parts of the cycle, then kick-starting glycolysis.

High levels of ADP → process turns on (eans you want to create ATP)

High ATP present → this will stay off (can only hold so much)

Question 24

Aerobic respiration has different control point along its enzymatic pathway to not allow it to continue unless needed. The second control point occurs right before the Krebs cycle begins using the enzyme called pyruvate dehydrogenase. What things occurring in your cell can turn this enzymes on and off? (know all the conditions we discussed in class)

Answer 24

Pyruvate Dehydrogenase: normally make pyruvate into acetyl CoA. Citrate levels decide if you can move to the Krebs cycle, so whether you need it or not will determine if it gets turned on or not.

Low levels of citrate → this will turn on and allow process to happen

High levels of Citrate → cycle won’t begin (because you don’t need it)

High NADH → turn off (no reason to produce anymore)

Low levels of NADH → turns on (you probably need the energy)

Question 25

Aerobic respiration has different control points along its enzymatic pathway to not allow it to continue unless needed. The third control point occurs at the beginning of the Krebs cycle using the enzyme called citrate synthase. What things occurring in your cell can turn this enzymes on and off? (know all the conditions we discussed in class)

Answer 25

Enzyme Citrate Synthase: Will tell you if you want to make the 4 carbon molecules to turn into citrate. If you want segment A to occur you need the enzyme.

High levels of ATP → turn off (not need to create process)

Low levels of ATP → turn on to create ATP