Chapter 4: Evolutionary Origin of Cells and Their General Features

Flashcards summarizing key concepts related to the structure and function of cells, focusing on organelles like mitochondria and chloroplasts, protein sorting, and cell organization.

What are semiautonomous organelles?

Mitochondria and chloroplasts that grow and divide, but depend on the cell for some functions.

How do mitochondria reproduce?

Mitochondria divide by a process called binary fission.

What type of genome do mitochondria and chloroplasts contain?

They each contain their own small genomes that resemble bacterial genomes.

What is the main function of mitochondria?

To provide most of the cell's ATP via aerobic cellular respiration.

What is the role of chloroplasts?

To capture light energy and synthesize organic molecules such as glucose.

What theory explains the origin of mitochondria and chloroplasts?

The endosymbiosis theory, which suggests they derived from ancestral prokaryotic cells.

What role do sorting signals play in protein sorting?

Short amino acid sequences that direct proteins to their correct destinations.

Describe co-translational sorting.

It begins during translation when an ER signal sequence is bound by a signal recognition particle (SRP).

What happens during post-translational sorting?

Proteins synthesized in the cytosol that are directed to mitochondria, chloroplasts, or other organelles.

What are the main functions of the endomembrane system?

Protein secretion, sorting, lipid synthesis, and degradation of organic molecules.