Cellular Respiration

Cellular respiration is the process by which cells break down glucose and other organic molecules to produce energy in the form of ATP (adenosine triphosphate).

Overview of Cellular Respiration

Cellular respiration consists of three main stages: glycolysis, the citric acid cycle (Krebs cycle), and oxidative phosphorylation (electron transport chain and chemiosmosis).

Glycolysis

Glycolysis takes place in the cytoplasm and involves the breakdown of glucose into two molecules of pyruvate. This process generates a small amount of ATP and NADH.

Citric Acid Cycle (Krebs Cycle)

The citric acid cycle occurs in the mitochondria and completes the breakdown of glucose by oxidizing pyruvate to carbon dioxide. It also produces NADH and FADH2, which carry high-energy electrons to the next stage of respiration.

Oxidative Phosphorylation

Oxidative phosphorylation takes place in the inner mitochondrial membrane and involves the transfer of electrons from NADH and FADH2 to oxygen through a series of protein complexes in the electron transport chain. This process generates a large amount of ATP through chemiosmosis.

Study Guide

What is the main purpose of cellular respiration?
Describe the three main stages of cellular respiration.
Where does glycolysis take place in the cell?
What are the products of the citric acid cycle?
Which stage of cellular respiration generates the most ATP?
Explain the role of NADH and FADH2 in cellular respiration.

By understanding the process of cellular respiration and its key stages, you will be able to grasp how organisms convert energy from organic molecules into ATP, which is essential for all cellular activities.

◂Biology Worksheets and Study Guides High School. Cell Reproduction

The resources above cover the following skills:

LIFE SCIENCE (NGSS)

From Molecules to Organisms: Structures and Processes

Students who demonstrate understanding can:

Construct an explanation based on evidence for how the structure of DNA determines the structure of proteins which carry out the essential functions of life through systems of specialized cells.

Use a model to illustrate the role of cellular division (mitosis) and differentiation in producing and maintaining complex organisms.

Construct and revise an explanation based on evidence for how carbon, hydrogen, and oxygen from sugar molecules may combine with other elements to form amino acids and/or other large carbon-based molecules.

Heredity: Inheritance and Variation of Traits

Students who demonstrate understanding can:

Ask questions to clarify relationships about the role of DNA and chromosomes in coding the instructions for characteristic traits passed from parents to offspring.

Make and defend a claim based on evidence that inheritable genetic variations may result from: (1) new genetic combinations through meiosis, (2) viable errors occurring during replication, and/or (3) mutations caused by environmental factors.