Miscellaneous

Question 1

In a mitochondrion what is the relationship between the inner membrane space, matrix and intermembrane space?

Answer 1

The inner membrane space separates the matric from the intermembrane space.

Question 2

What is the role of enzymes in the CAC?

Answer 2

Oxidised coenzymes are converted to electron-rich coenzymes in multiple chemical reactions and the electron-rich coenzymes are then taken to ETC.

Question 3

Excess dietary carbohydrate is converted to ____________ and ____________ via
separate metabolic reactions.

Answer 3

Glycogen and Fat

Question 4

Which of the following coenzymes is required for the chemical reaction in step 6 of
glycolysis?
NADH, NAD+, ATP, pyruvate, glycogen

Answer 4

NAD+

Question 5

What do enzymes in the small intestine do to assist breaking down carbohydrates into smaller
sugars (such as monosaccharides and disaccharides)?

Answer 5

Each carbohydrate requires a specific enzyme to cleave their glycosidic bonds that link the sugar units
together in order to create smaller sugars (usually monosaccharides).

Question 6

How are the carbohydrate digestion products transported into the bloodstream? Where are the monosaccharides taken once in the blood?

Answer 6

Monosaccharides are absorbed by the lining of
the small intestine (via active transport), which allows them (glucose, fructose, galactose) to enter the blood.

Once in the blood the monosaccharides are taken to the liver to be metabolised.

Question 7

Where does the input required for glycolysis come from?

Answer 7

Glucose = from the digestion of complex carbohydrates.

Glucose enters the blood after digestion, the release of insulin promotes the movement of glucose into the cell, it can then be used in glycolysis.

Question 8

The formation of lactate from pyruvate requires what chemical reaction and what reactant/product?

Answer 8

The oxidation of NADH to NAD

Question 9

Which two of the following substances are participants in the reactions encompassed by the
Cori cycle?

Pyruvate
lactate
acetyl CoA

Answer 9

Pyruvate and lactate

Question 10

How many NADH and FADH2 are made through the CAC? And what is the product?

Answer 10

Three NADH
Two FADH2
Oxaloacetate

Question 11

What is an allosteric enzyme?

Answer 11

contains regulatory sites

Question 12

Name the 2 sources that Acetyl coA can come from.

Answer 12

Glucose through glycolysis.

Beta-oxidation of FAs

Question 13

What is oxaloacetate produced from?

Answer 13

Malate via CAC

also made form pyruvate

Question 14

What does the Cori Cycle do?

Answer 14

Allows lactic acid produced in skeletal muscles to be converted to glucose in the liver by gluconeogenesis.

Question 15

Cori Cycle: Lactate forms in the muscles during exercise, then diffuses from muscle cells into the bloodstream, then what happens?

Answer 15

Lactate diffuses through the blood and into the liver.
Is converted to pyruvate
Converted to Glucose via gluconeogenesis
Glucose is passed into the blood, and then into the muscles where is can be converted to pruvate via glycolysis.

Question 16

What is the name of the process in which glucose 6-phosphate is converted to glycogen?
Gluconeogenesis
Glycolysis
glycogenesis
Glycogenolysis

Answer 16

glycogenesis

Question 17

Glycogen is converted to glucose in which of the following processes?
Gluconeogenesis
Glycogenesis
Glycogenolysis
Glycolysis

Answer 17

Glycogenolysis

Question 18

Where does the ETC occur?
mitochondrial matrix
inner membrane
intermembrane space
outer membrane

Answer 18

Complexes I to IV are embedded in the inner membrane of the mitochondria so ETC takes place here.

Question 19

Where does OP occur?
mitochondrial matrix
inner membrane
intermembrane space
outer membrane.

Answer 19

matrix, inner membrane and intermembrane space are all involved.

H+ are pumped from the matrix into IMS through complexes I, II, IV.

Once enough H+ have built up in IMS they move back into matrix via ATP synthase which is in inner membrane.

Question 20

What is the output of the ETC?

Answer 20

When oxygen accepts electrons from complex IV it becomes H2O (oxygen also accepts some H+), which is the output of the ETC. Oxygen must be present to use as the final electron acceptor for the generation of ATP.

Question 21

How are electrons stripped from the NADH

coenzyme by complex I of the ETC.

Answer 21

The electrons are stripped off NADH via a redox reaction.

One of the components of complex I (FMN) accepts the electrons from NADH, causing NADH to be oxidised to NAD+. The electrons are then passed along the ETC.

NAD+ is taken back to the CAC to be used in the redox reaction steps.

Question 22

How are electrons passed through the complexes in the ETC?

Answer 22

Mobile electron carriers: CoQ and cytochrome C

CoQ carries electrons from complexes I and II to complex III

Cyt C carries electrons from complex III to complex IV.

Question 23

In OP - How does the movement of H+

through ATP synthase regenerate ATP?

Answer 23

The H+ gradient generates energy as H+ moves through ATP synthase and this energy is harnessed to regenerate ATP along with one Phosphate unit.

Question 24

Why is it important that oxygen is present to function as the final electron acceptor of the ETC?

Answer 24

Electrons must be taken off the chain or they would stop moving through the ETC, OP would also stop and ATP could not be produced. So electrons from complex IV must be accepted by oxygen to continue the cycle.

Question 25

As electrons are passed along the complexes within the ETC, the complexes I, III and IV open their H+ channels.

What happens once these H+ channels are open? How does this process link the ETC to OP?

Answer 25

The open H+ channels of the ETC complexes allows H+
to move from the matrix into the intermembrane space.

As more electrons move through the ETC, more H+ are
pumped into the intermembrane space (between the inner and outer membrane).

When the concentration of H+ is high in the intermembrane space, OP begins and the H+ move through ATP synthase back into the matrix.

Question 26

Once there is a high concentration of H+ in the intermembrane space, the H+ move through ATP synthase back into the matrix. How does the movement of H+ through ATP synthase regenerate ATP?

Answer 26

Once H+ start to move through ATP synthase (from the intermembrane space into the matrix) an H+ gradient is generated.

The H+ gradient (movement) generates energy, which is harnessed by the ATP synthase enzyme to regenerate ATP.

A phosphate unit is attached to an ADP in the presence of energy (from H+ movement
through ATP synthase) to regenerate ATP:

ADP + Pi + energy (H+ movement) → ATP