Chapter 4: Evolutionary Origin of Cells and Their General Features

These flashcards cover key concepts from Chapter 4, focusing on the evolutionary origin of cells, their general features, and the differences between prokaryotic and eukaryotic cells.

What are the stages in the origin of living cells on Earth?

1. Production of nucleotides and amino acids 2. Polymerization of nucleotides to form RNA and/or DNA, and amino acids to form proteins 3. Enclosure of polymers in membranes 4. Acquisition of properties of living cells by these polymers.

What is the cell theory?

1. All living organisms are composed of one or more cells 2. Cells are the smallest units of life 3. New cells arise only from pre-existing cells.

What differentiates prokaryotic cells from eukaryotic cells?

Prokaryotic cells are simple with no nucleus, while eukaryotic cells have a membrane-bound nucleus and organelles.

What are the main functions of lysosomes?

Contain acid hydrolases to perform hydrolysis, break down various biomolecules, and digest molecules taken in by endocytosis.

What are semiautonomous organelles?

Mitochondria and chloroplasts, which can grow and divide independently but depend on the cell for synthesis of some internal components.

What is the role of the Golgi apparatus?

Involved in secretion, processing, and protein sorting.

What determines the characteristics of a cell?

The proteome largely determines cell characteristics, despite identical DNA across different cell types.

What is the function of the cytoskeleton?

Provides shape, organization, and movement through a network of protein filaments.

Define endosymbiosis. What theory does it relate to?

Endosymbiosis is a symbiotic relationship where a smaller species lives within a larger one; relates to the theory that mitochondria and chloroplasts originated from bacteria.

What role do glycosaminoglycans (GAGs) play in the extracellular matrix?

They resist compression and help form a gel that protects cells.

What is Systems Biology?

The study of how new properties of life arise from complex interactions of cellular components.

What structures are typically found in a prokaryotic cell?

Plasma membrane, cytoplasm, nucleoid region, ribosomes, cell wall, glycocalyx, pili, and flagella.

What are the differences between rough and smooth endoplasmic reticulum?

Rough ER is studded with ribosomes and involved in protein synthesis, while smooth ER lacks ribosomes and is involved in lipid synthesis and detoxification.