Cellular Respiration

Even though respiration is an energy-releasing process, a small amount of energy must be invested to get the reactions going. During glycolysis, the energy of ___a___ ATP is consumed, but by the end of the process ___b___ ATP are produced

(a) 2 ATP are consumed. (b) 4 ATP are produced.

How many FADH2 are produced in glycolysis, the bridge reaction, and krebs cycle?

0 FADH2 in glycolysis, 0 FADH2 in the bridge reaction, and 2 FADH2 in the Kreb cycle

How many molecules of NADH are produced during glycolysis?

2

How many ATP are produced for each FADH2 entering the electron transport chain

2 ATP

List three end products of glycolysis

2 molecules of pyruvic acid, 2 NADH, and a net gain of 2 ATP

How many ATP are produced for each NADH entering the electron transport chain

3 ATP

What is the total amount of Carbon Dioxide, ATP, NADH, and FADH2 produced during the Krebs cycle per molecule of glucose?

4 CO2, 2 ATP, 6 NADH,2 FADH2

What molecule is formed when NAD+ accepts a pair of high-energy electrons?

NADH

List three basic components of an ATP molecule

The nitrogen base, adenine, five-carbon sugar, ribose, and three phosphate molecules.

What is the total amount of Carbon Dioxide, ATP, NADH, and FADH2 produced during the Krebs cycle per molecule of pyruvic acid?

2 CO2, 1 ATP, 3 NADH, 1 FADH2

How many NADH are produced in glycolysis, the bridge reaction, and krebs cycle?

2 NADH in glycolysis, 2 NADH in the bridge reaction, 6 NADH in the Krebs cycle.

In summary, for each molecule of glucose entering respiration, approximately how many ATP can be produced?

38 ATP

List three products that are continually produced in the Krebs cycle.

ATP, NADH, FADH2, and CO2

The Krebs cycle begins with a series of reactions that are sometimes referred to as the bridge reactions. In this set of reactions, pyruvic acid is converted into what compound?

Acetyl-CoA

How many ATP are produced in glycolysis, Kreb cycle, and ETS stages?

Net gain of 2 ATP in glycolysis, 2 ATP in Krebs cycle, 34 ATP in electron transport chain.

During fermentation, approximately how many ATP can be produced per molecule of glucose?

Fermentation will yield only a gain of 2 ATP per molecule of glucose.

Describe the process of glycolysis in one sentence

Glycolysis is the process in which a molecule of glucose is oxidized to produce two molecules of pyruvic acid

Explain how the electron transport chain produces ATP.

Hydrogen ions flow through ATP synthase from the intermembrane space back into the matrix of the mitochondria. This flow of hydrogen ions spins a rotor within ATP synthase. Each time it rotates a phosphate is attached to ADP to form ATP.

What are two possible paths for the pyruvic acid molecules produced in glycolysis?

If oxygen is present, the pyruvic acid will enter the mitochondria for the Krebs cycle.If oxygen is absent, the pyruvic acid will remain in the cytoplasm for fermentation.

What is a disadvantage of glycolysis?

If the cell relied only on glycolysis for ATP production, the cell would quickly run out of NAD+ to accept the hydrogen electrons. Without NAD+, the cell cannot keep glycolysis going and ATP production would stop.

The Krebs cycle begins with a series of reactions that are sometimes referred to as the bridge reactions. Explain why this name (bridge reaction) is used.

It is the bridge between: the cytoplasm and the mitochondrion, anaerobic and aerobic respiration glycolysis and the Krebs cycle.

What are NAD+ and FAD, and what is their role in the Krebs cycle?

NAD+ and FAD are electron carriers. They will deliver the high-energy electrons of hydrogen to the electron transport chain

What is NAD+ and what is its role in cellular respiration?

NAD+ is an electron carrier. It accepts a pair of high-energy electrons and holds them until they can be transferred to other molecules

The Krebs cycle begins when _________ produced by glycolysis enters the mitochondrion

Pyruvic acid

For each molecule of glucose in cellular respiration, how many molecules of carbon dioxide are produced? In which stage(s) are they produced?

Six molecules of carbon dioxide are produced for each molecule of glucose. Two are produced by the bridge reaction as pyruvic acid enters the mitochondria. The other four are produced in the Krebs cycle.

What happens to the ATP that is produced during the Krebs cycle?

The ATP is used as a source of energy for cellular processes.

Describe the Krebs cycle in one sentence

The Krebs cycle completes the oxidation of glucose by releasing carbon dioxide, producing a small amount of ATP, and storing high-energy electrons in molecules of NADH

What happens to the NADH and FADH2 molecules that are produced during the Krebs cycle?

The NADH and FADH2 will be used in the electron transport chain to generate large amounts of ATP.

What happens to the carbon dioxide that is produced during the Krebs cycle?

The carbon dioxide is released as a waste product.

Describe the electron transport chain in one sentence

The electron transport chain uses the high-energy electrons from glycolysis and the Krebs cycle to convert ADP to ATP

The high-energy electrons from NADH and FADH2 are passed along the electron transport chain. As they are passed from one protein to the next, they release energy. What is this energy used for?

The energy is used to pump hydrogen protons (H+) from the matrix into the intermembrane space. These protons are pumped against the concentration gradient.

What name is given to these loops and folds, and what is their purpose?

The loops and folds are called cristae. These membranes increase the surface area for the reactions of the electron transport chain.

As molecules of NADH are produced, they will be delivered to what stage of respiration?

The molecules of NADH are used in the electron transport chain

For each pyruvic acid converted to acetyl-CoA: a) How many molecules of NADH are formed? What happens to them? b) How many molecules of carbon dioxide are formed? What happens to them?

a) Two molecules of NADH are formed. The high-energy electrons being carried by NAD+ will be used in the electron transport chain. b) Two molecules of carbon dioxide are formed. They are released as a waste product.