Cell Structure Class

Question 1

Substrate-level Phosphorylation

Answer 1

As a glucose molecule is gradually broken down, some of the breakdowns steps release energy that is captured directly as ATP. In these steps, a phosphate group is transferred from a pathway intermediate straight to ADP, a process known as substrate-level phosphorylation.

Question 2

Oxidative Phosphorylation

Answer 2

As an electron passes through the electron transport chain, the energy it releases is used to pump protons (H​+)
​out of the matrix of the mitochondrion, forming an electrochemical gradient. When the H​+ flow back down their gradient, they pass through an enzyme called ATP synthase, driving synthesis of ATP. This process is known as oxidative phosphorylation.

Question 3

Cellular Respiration

Answer 3

When organic fuels like glucose are broken down using an electron transport chain, the breakdown process is known as cellular respiration.

Question 4

Electron Carriers

Answer 4

also called electron shuttles, are small organic molecules that play key roles in cellular respiration.
2 Types: NAD+ and FAD

Question 5

When NAD+ and FAD pick up electrons, what do they gain?

Answer 5

One or more H atoms, making them NADH + H+ and FADH2.

Once they drop the electrons off, they go right back to their original state.

Question 6

Oxidation-Reduction Reaction (redox reactions)

Answer 6

Reactions involving electron transfers

Question 7

Oxidized

Answer 7

Lost elections (reducing agent)

Question 8

Reduced

Answer 8

Gained electrons (oxidizing agent)

Question 9

In cellular respiration what is oxidized?

Answer 9

Carbon

Question 10

In cellular respiration what is reduced?

Answer 10

Oxygen

Question 11

Higher Energy to Lower Energy?

Answer 11

Energy Released

Question 12

Cellular Respiration Delta G outcome?

Answer 12

Delta G= -686 kcal/mol

Question 13

Which of the following correctly describes the structure of ATP and how it provides energy?

Answer 13

ATP contains a 5-carbon sugar, three phosphate groups, and an adenine base. Energy is released when the bond between the second phosphate group and third phosphate group is broken.

Question 14

What is true of NAD in cellular respiration?

Answer 14

NAD carries and transfers electrons and H+ ions.

Question 15

Glycolysis occurs where?

Answer 15

In the cytosol

Question 16

Glycolysis

Answer 16

In glycolysis, glucose—a six-carbon sugar—undergoes a series of chemical transformations. In the end, it gets converted into two molecules of pyruvate, a three-carbon organic molecule. In these reactions, ATP is made, and
NAD+ is converted to NADH
Oxygen Independent

Question 17

Pyruvate Oxidation

Answer 17

Each pyruvate from glycolysis goes into the mitochondrial matrix—the innermost compartment of mitochondria. There, it’s converted into a two-carbon molecule bound to Coenzyme A, known as acetyl CoA. Carbon dioxide is released and NADH is generated.

Question 18

Citric Acid Cycle

Answer 18

The acetyl CoA made in the last step combines with a four-carbon molecule and goes through a cycle of reactions, ultimately regenerating the four-carbon starting molecule. ATP, NADH, FADH​2 are produced, and carbon dioxide is released.