Biology: Oxidative Phosphorylation and Electron Transport Chain

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

During glycolysis, what is one glucose molecule broken down into?

Two molecules of pyruvate (correct)

Three molecules of ATP

Four molecules of ATP

One molecule of NADH

How many ATP molecules are produced directly during the Citric Acid Cycle for each glucose molecule?

1 ATP

6 ATP

2 ATP (correct)

4 ATP

What are NADH and FADH2 used for in oxidative phosphorylation?

Breaking down pyruvate

Transferring electrons in electron transport chains (correct)

Storing glucose

Transporting oxygen molecules

What is the net gain of ATP from glycolysis?

2 ATP Signup and view all the answers

What maximum number of ATP can oxidative phosphorylation produce?

34 ATP Signup and view all the answers

What creates a proton gradient in the mitochondria?

Pumping of protons out of the inner membrane Signup and view all the answers

Which complex is powered by the proton gradient to produce ATP?

ATP synthase Signup and view all the answers

What happens at the end of the electron transport chain?

Electrons combine with oxygen and protons to form water Signup and view all the answers

What is used to pump protons into a space to create a gradient?

Oxidation of NADH and FADH2 Signup and view all the answers

How does the proton gradient power the production of ATP?

By flowing into the mitochondria through ATP synthase Signup and view all the answers

What drives the production of ATP in oxidative phosphorylation?

A proton gradient Signup and view all the answers

Where are the complexes involved in electron transport located?

In the inner membrane of mitochondria Signup and view all the answers

What do the complexes in electron transport take electrons from?

Molecules that come from food Signup and view all the answers

What happens to electrons as they move from one protein complex to the next in energy transfer?

They lose energy Signup and view all the answers

What do protein complexes use energy from electrons to do?

Pump protons (H+ ions) from inside mitochondria Signup and view all the answers

What is the effect of dehydrogenation on a beta carbon?

Turns an -OH group into a C=O double bond Signup and view all the answers

What is the main purpose of the acetyl-transfer process?

To produce energy in the citric acid cycle Signup and view all the answers

In which cellular location does fatty acid synthesis occur?

Cytosol Signup and view all the answers

What is the initial molecule used in the conversion process during fatty acid synthesis?

Acetyl-CoA Signup and view all the answers

How is acetyl-CoA transported from the mitochondria to the cytosol for fatty acid synthesis?

As citrate Signup and view all the answers

What molecule is formed when fatty acids are attached to CoA?

Acetyl-CoA Signup and view all the answers

What is the role of carnitine in the metabolism of fatty acids?

To transport fatty acids into the mitochondria Signup and view all the answers

Which cycle does Acetyl-CoA enter to help produce high energy molecules?

Citric acid cycle Signup and view all the answers

What differentiates Acyl-CoA from Acetyl-CoA?

Acyl-CoA has a longer carbon chain Signup and view all the answers

What is DHAP derived from?

Fructose 1-phosphate Signup and view all the answers

Which of the following statements is true about Acetyl-CoA?

Acetyl-CoA contains two carbon acetyls. Signup and view all the answers

What is the main function of Acyl-CoA in metabolism?

Acyl-CoA is involved in the metabolism of fatty acids. Signup and view all the answers

What happens during the dehydrogenation step?

Hydrogen atoms are removed and transferred to FAD+. Signup and view all the answers

In the hydration step, what effect does adding water have on the double bond?

The double bond is converted to a single bond. Signup and view all the answers

Which of the following differentiates Acetyl-CoA from Acyl-CoA?

Acetyl-CoA contains two carbon acetyls. Signup and view all the answers

What is done with proteins instead of storing them as energy?

They are recycled as amino acids. Signup and view all the answers

Which intermediate product is associated with the urea cycle?

Urea Signup and view all the answers

What role do carbon skeletons of amino acids play in the TCA cycle?

They act as intermediates for ATP production. Signup and view all the answers

Why is ammonia removed from the body?

It is toxic to the body. Signup and view all the answers

Which process is involved in the conversion of carbon skeletons to glucose?

Gluconeogenesis Signup and view all the answers

What is formed when the amino group from an amino acid is transferred to alpha-ketoglutarate?

Glutamate Signup and view all the answers

What happens to the remaining carbon part of an amino acid after the amino group has been removed?

It forms alpha-keto acid Signup and view all the answers

During exercise, what do muscles produce that is later converted into pyruvate?

Alanine Signup and view all the answers

What role does pyruvate play after being converted from alanine in the liver?

It is used to make glucose Signup and view all the answers

Which compound carries the amino group into the urea cycle for disposal?

Glutamate Signup and view all the answers

What is produced when ornithine reacts with carbamoyl phosphate?

Citrulline Signup and view all the answers

Which molecule combines with citrulline after it exits the mitochondria?

Aspartate Signup and view all the answers

What does the reaction of arginosuccinate produce, aside from arginine?

Fumarate Signup and view all the answers

What role does alpha ketoglutarate play in the urea cycle?

It generates glutamate. Signup and view all the answers

What initiates the urea cycle by using amino groups and energy?

Carbamoyl-phosphate Signup and view all the answers

What is regenerated in the final step of the urea cycle?

Ornithine Signup and view all the answers

Where does one of the amino groups in the urea cycle come from?

Amino acids transported into the mitochondria Signup and view all the answers

Which TCA cycle intermediate is aspartate derived from?

Oxaloacetate Signup and view all the answers

What process utilizes glucogenic amino acids?

TCA cycle to make energy or glucose Signup and view all the answers

Ketogenic amino acids are primarily used in which process?

Production of ketone bodies or fats Signup and view all the answers

Study Notes

Oxidative Phosphorylation and Electron Transport Chain

Oxidative phosphorylation uses energy from moving electrons to create a proton gradient, which drives ATP production.
The process involves three main steps: electron transport chain, electron movement, and energy transfer.

Electron Transport Chain

Electrons transfer energy to pumps, creating a proton gradient used to produce ATP.
Complexes involved in electron transport are located in the inner mitochondrial membrane.
These complexes take electrons from molecules that come from food.

Creating a Gradient

Pumping protons out creates a high concentration of protons outside the inner membrane compared to inside.
This creates a proton gradient.

ATP Production

A proton gradient powers ATP synthase, allowing protons to flow back into the mitochondria.
This process produces ATP.

Water Formation

At the end of the electron transport chain, electrons combine with oxygen and protons to form water.

Process

The process uses energy from oxidizing NADH and FADH2 to pump protons into a space, creating a gradient.
This gradient powers the production of ATP as protons flow into the mitochondria.

ATP Production from Glucose

Cells produce ATP from glucose in three main stages: glycolysis, citric acid cycle, and oxidative phosphorylation.

Glycolysis

One glucose molecule is broken down into two pyruvate molecules, producing a net gain of 2 ATP.

Citric Acid Cycle

Each pyruvate is broken down in a cycle that must turn twice for each glucose molecule.
Two cycles produce 2 ATP directly and create NADH + FADH2.

Oxidative Phosphorylation

NADH + FADH2 are used in electron transport chains, producing up to 34 ATP.

Dehydrogenation

Dehydrogenation changes the -OH group on the beta carbon into a C=O double bond, making it more reactive.

Acetyl-transfer

Acetyl-transfer breaks fatty acid chains into smaller pieces, creating acetyl-CoA, and produces energy in the citric acid cycle.

Fatty Acid Synthesis

Fatty acid synthesis occurs in the cytosol, involving the conversion of acetyl-CoA into a 3-carbon molecule called malonyl-CoA.
More acetyl groups are added to build a longer fatty acid chain.

Fatty Acid Breakdown

Fatty acids are attached to CoA, forming acetyl-CoA, and are broken down into smaller pieces, each with 2 carbon atoms, to produce energy.

Difference Between Acetyl-CoA and Acyl-CoA

Acyl-CoA has a longer carbon chain and is involved in the metabolism of fatty acids.
Acetyl-CoA contains two carbon acetyls and is central in energy production, entering the citric acid cycle to generate energy.

4 Steps in Total

Dehydrogenation removes hydrogen atoms from a specific place in a molecule, transferring them to FAD+ and forming a double bond between neighboring carbon atoms.
Hydration adds water to the double bond, changing it to a single bond and attaching a hydroxyl group to the beta carbon.

Breakdown of Amino Acids

Amino acids are recycled, and their carbon skeletons can be used as intermediates in the TCA cycle.
Amino groups are converted into carbamoyl phosphate for the urea cycle, while the remaining carbon part becomes an alpha-keto acid.

Amino Acid Degradation and Nitrogen Excretion

Amino group from an amino acid is converted into carbamoyl phosphate for the urea cycle.
The remaining carbon part becomes an alpha-keto acid, which can be used for energy or glucose production.

Urea Cycle

Amino group is added to alpha-ketoglutarate to make glutamate, and then removed from glutamate to regenerate alpha-ketoglutarate.
Urea cycle starts by using amino groups and energy to make carbamoyl-phosphate.

Urea Cycle Steps

Ornithine reacts with carbamoyl phosphate to make citrulline.
Citrulline exits mitochondria and combines with aspartate to form arginosuccinate.
Arginosuccinate undergoes a reaction to produce arginine and release fumarate.
Arginine breaks down to regenerate ornithine, completing the urea cycle.

Key Points

One amino group in the cycle comes from amino acids that have been transported into mitochondria.
Other amino groups come from aspartate, derived from oxaloacetate in the TCA cycle.

Krebs Cycle

Glucogenic amino acids provide carbon skeletons that go into the TCA cycle to make energy or glucose.
Ketogenic amino acids are used in processes that lead to the production of ketone bodies or fats for energy.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Description

Learn about the process of oxidative phosphorylation, which generates ATP through electron transport chain, creating a proton gradient in mitochondria.