Metabolism: Glycolysis Steps Flashcards

Questions and Answers

What are the four sets of reactions involved in glucose catabolism?

Glycolysis

Kreb's Cycle

Electron Transport Chain

All of the above (correct)

What occurs in Glycolysis Step 1?

Glucose splits into 2 pyruvic acids.

Glycolysis Step 2 requires oxygen.

False

Glycolysis occurs in the mitochondria.

False Signup and view all the answers

In Glycolysis Step 5, what is transported to the electron transport chain?

NADH Signup and view all the answers

Match the glycolysis steps with their descriptions:

Step 1 = Glucose splits into pyruvic acids Step 3 = Occurs in the cytosol of all living things Step 4 = ATP produced is used immediately Step 6 = Conversion of pyruvic acid depends on the presence of O2 Signup and view all the answers

What is produced and diffuses out of the cell in Acetyl CoA Step 1?

CO2 Signup and view all the answers

Acetic acid attaches to ____ for transport to form Acetyl CoA.

CoA Signup and view all the answers

What is the reason the Kreb's cycle is called a cycle?

Both A and B Signup and view all the answers

What happens to H+ and depleted energy electrons at the end of the electron transport chain?

They bind with oxygen to form H2O. Signup and view all the answers

ATP is synthesized as electrons flow along the electron transport chain.

True Signup and view all the answers

Study Notes

Glucose Catabolism Overview

Cellular respiration involves four main stages: Glycolysis, Acetyl CoA formation, Kreb's cycle, and Electron transport chain (ETC).
Glycolysis is the first stage and occurs in the cytosol.

Glycolysis Steps

Step 1: Glucose (6C) breaks down into 2 pyruvic acids (3C) through a series of 10 enzymatic reactions.
Step 2: Glycolysis occurs without oxygen, qualifying as anaerobic respiration.
Step 3: This process happens in the cytosol of all organisms, including bacteria.
Step 4: ATP generated during glycolysis is used immediately by the cell.
Step 5: NADH is produced and carries high-energy electrons to the electron transport chain in mitochondria.
Step 6: Pyruvic acid conversion is contingent on oxygen availability:
- Anaerobic conversion results in lactic acid, which diffuses into the bloodstream and can be transformed back to pyruvic acid in the liver.
- Aerobic conversion allows pyruvic acid to move into mitochondria for further processing.

Acetyl CoA Formation

Step 1: Pyruvic acid is transformed into acetic acid before entering the Kreb's cycle, producing CO2 and transferring H+ and electrons to NAD, forming NADH.
Step 2: Acetic acid is then joined with CoA, creating Acetyl CoA for transport.
Step 3: Acetyl CoA is introduced into the Kreb's cycle.

Kreb's Cycle Mechanics

Step 1: CoA releases acetic acid to initiate the cycle and returns for more.
The cycle regenerates the starting molecule, oxaloacetic acid, by completing a full turn.
Each glucose molecule results in two cycles yielding:
- 4 CO2 expelled (2 per cycle)
- 6 NADH and 2 FADH formed, which move to the ETC for ATP production.

Electron Transport Chain (ETC) Process

Step 1: Coenzymes (NAD and FADH) carry energy-rich electrons and H+ ions from glycolysis, Acetyl CoA formation, and the Kreb's cycle.
- Electrons detach from hydrogen, resulting in NADH and FADH, which enter the ETC.
- H+ ions remain, creating a concentration gradient in mitochondria.
Step 2: ATP is synthesized during the electron flow along the chain, a process known as Chemiosmosis.
Step 3: Oxygen acts as the final electron acceptor, crucial for the chain's function.
Step 4: H+ ions, electrons, and oxygen combine to form water (H2O).

Description

Test your knowledge on glucose catabolism through these flashcards that cover key steps in glycolysis and subsequent reactions involved in cellular respiration. Understand the breakdown of glucose into pyruvic acid and the role of essential enzymes in each step.