Chapter 4 Cell Structure and Function Flashcards

A set of vocabulary flashcards reviewing Chapter 4 lecture material on cell theory, prokaryotic vs. eukaryotic cell structures, cellular organelles, membrane composition, and biological measurements.

Cell theory

The foundational biological principle stating that cells are the units of structure and function in all living organisms, and that all cells arise from preexisting cells.

Unicellular organism

An organism consisting of a single cell that carries out all life functions, such as bacteria, archaea, yeast, and most protists.

Multicellular organism

An organism composed of multiple interdependent cells that display division of labor and specialized functions, such as plants, animals, most fungi, and seaweeds.

Prokaryotic cell

A smaller, simpler, ancient type of cell that lacks organelles and a nucleus, containing a single circular chromosome located in a nucleoid region.

Eukaryotic cell

A larger, more complex cell type with compartmentalized chemical reactions, containing a membrane-enclosed nucleus with paired chromosomes and numerous organelles.

Peptidoglycan

A mesh-like polymer composed of sugar and amino acids that forms the cell wall in bacteria.

Cellulose

The rigid carbohydrate material that forms the cell wall of plant cells.

Chitin

The tough structural carbohydrate that forms the cell wall of fungi.

Nucleoid region

The region in a prokaryotic cell where the single circular DNA chromosome is attached to the inside of the plasma membrane.

Plasmids

Extra, tiny circular DNA molecules present inside prokaryotic cells.

Flagella

Long whip-like cellular extensions that rotate like propellers to propel cells.

Pili

Structures on the surface of prokaryotic cells that function as attachment structures to help them stick to surfaces.

Capsule

A sticky outer coating on prokaryotic cells that aids in attachment to surfaces.

Organelle

A membrane-enclosed structure in eukaryotic cells that performs a specific function to allow compartmentalization of chemical reactions.

Cytoplasm

The entire region of a eukaryotic cell located between the nucleus and the plasma membrane.

Cytosol

The fluid or liquid portion of the cytoplasm.

Phospholipid bilayer

A double-layered membrane structure consisting of hydrophilic polar phosphate heads facing outward and hydrophobic nonpolar fatty acid tails facing inward.

Extracellular matrix (ECM)

A substance secreted between the plasma membranes of animal cells that holds cells together to form tissues and organs.

Micrometer ($\mu\text{m}$)

A unit of length equal to $10^{-6}\,\text{m}$ or $10^{-3}\,\text{mm}$.

Nanometer ($\text{nm}$)

A unit of length equal to $10^{-9}\,\text{m}$ or $10^{-3}\,\mu\text{m}$.