Biol 103: Introductory Biology I - Lecture 3 Cells

These flashcards cover key vocabulary related to cell biology, including cell theory, organelle functions, and cell structure types.

Cell Theory

Composite of three principles: all organisms are composed of cells, the cell is the basic unit of life, and all cells arise from other cells.

Eukaryotic Cells

Cells with a true nucleus and membrane-bound organelles found in organisms of the domain Eukarya.

Prokaryotic Cells

Cells without a true nucleus or membrane-bound organelles, primarily bacteria and archaea.

Plasma Membrane

The lipid bilayer that surrounds all cells, acting as a barrier to water-soluble substances.

Microscopy

Techniques used to view cells, including light and electron microscopy.

Ribosomes

Molecular machines that synthesize proteins by translating messenger RNA.

Endoplasmic Reticulum (ER)

An organelle involved in the synthesis of proteins (Rough ER) and lipids (Smooth ER).

Golgi Apparatus

An organelle responsible for modifying, sorting, and packaging proteins for secretion.

Lysosomes

Organelles that contain digestive enzymes to break down waste materials and cellular debris.

Chloroplasts

Organelles in plant cells that conduct photosynthesis, converting light energy into chemical energy.

Mitochondria

Organelles known as the powerhouses of the cell, where cellular respiration occurs.

Transport Proteins

Proteins that facilitate the movement of ions and molecules across the plasma membrane.

Microtubules

Cytoskeletal structures that provide support and shape to cells, and are involved in transport and cell division.

Cytoskeleton

A network of fibers that maintains cell shape, provides support, and facilitates movement.

Eukarya

The domain that includes all eukaryotic organisms, which have complex cells.

Cell Size Limitations

Cell size is constrained by surface area-to-volume ratio, affecting nutrient intake and waste removal.

Intercellular Junctions

Structures that facilitate communication and connection between adjacent cells.

Gap Junctions

Channels that allow for direct chemical communication between neighboring cells.

Tight Junctions

Seals between cells that prevent passage of molecules between the cells.

Desmosomes

Anchoring junctions that provide mechanical strength to tissues.

Electron Microscopes

Instruments that use electrons to magnify specimens, offering higher resolution than light microscopes.

Scanned Electron Microscopes

Electron microscopy technique that produces 3D images of the surface of a specimen.

Transmission Electron Microscopes

Electron microscopy technique that provides detailed images of the internal structures of cells.

Cell Wall

A rigid outer layer found in plant cells, providing structural support and protection.

Endosymbiotic Theory

The theory explaining the origin of mitochondria and chloroplasts as a result of symbiosis.

Vesicles

Small membrane-bound sacs that transport materials within a cell.

Cilia

Hair-like structures that protrude from the cell surface, involved in movement and sensory functions.

Flagella

Long, whip-like structures that propel cells through fluid environments.

Nuclear Envelope

Double membrane surrounding the nucleus, containing nuclear pores for molecular transport.

Chromatin

Complex of DNA and proteins found in eukaryotic nuclei, condensing to form chromosomes during cell division.

Plasmodesmata

Channels that connect plant cells, allowing for the transport of materials and communication.

Microfilaments

The smallest fibers of the cytoskeleton, made up of actin, involved in cell movement and shape.

Intermediate Filaments

Fibrous proteins of the cytoskeleton that provide structural support and resilience to cells.

Cytosol

The fluid component of the cytoplasm in which organelles are suspended.