Cell Biology and Transport Mechanisms Vocabulary

Vocabulary terms covering cell membrane transport, bacterial internal structures, and eukaryotic cell components based on the lecture transcript.

Osmosis

The net movement of water molecules from an area of higher water concentration to an area of lower water concentration across a semi-permeable membrane.

Passive transport

The movement of substances across a cell membrane along their concentration gradient (from high concentration to low concentration) without the expenditure of cellular energy.

Active transport

The movement of substances across a cell membrane against their concentration gradient (from low concentration to high concentration), requiring cellular energy such as ATP.

Facilitated diffusion

A passive transport process where substances move down their concentration gradient across a cell membrane with the assistance of membrane transport proteins.

Aquaporin

A specialized membrane channel protein that specifically facilitates the rapid movement of water molecules across the cell membrane.

Group translocation

A form of active transport in prokaryotes where a substance is chemically altered or modified as it is transported across the cell membrane.

Phosphoenolpyruvate (PEP)

An energy-rich compound used in group translocation to donate a phosphate group and chemically alter molecules like glucose as they enter the cell.

Cytoskeleton

A network of structural proteins inside the cytoplasm that maintains cell shape and serves as an internal transport system for moving materials efficiently.

Plasmid

Small, extra-chromosomal circular rings of DNA found in bacteria that carry non-essential genes allowing adaptation to novel environments.

70S Ribosome

The prokaryotic ribosome responsible for protein translation, composed of a 30S small subunit and a 50S large subunit based on sedimentation rate.

Inclusions

Reserve deposits within the cytoplasm of bacterial cells that store nutrients and compounds such as phosphates, lipids, or specific enzymes.

Endospore

A durable, dormant survival structure formed by certain bacteria to withstand unfavorable environmental conditions like drying out.

9+2 arrangement

The characteristic structural arrangement of microtubules in eukaryotic flagella and cilia, consisting of nine outer doublets surrounding two central single microtubules.

Extracellular matrix (Glycocalyx)

A carbohydrate-rich outer cell surface coating present in eukaryotic cells that facilitates cell-to-cell recognition and structural adhesion.