PHYSL 212 Lecture 1 - Cellular Structure (Terms)

Organelle

Specialized structures contained within cells that carry out necessary functions to sustain the cell

Nucleus

The organelle responsible for the storage of DNA in the form of chromatin

Nuclear Envelope

The membrane of the nucleus that facilitates passage of RNA into the cytoplasm and the entrance of proteins that modulate gene expression

Nucleolus

A sub-cellular organelle that is the site of ribosomal RNA synthesis and the protein components of ribosomes

Ribosomes

Small abundant organelles that act as a “protein factory” by translating RNA into protein

Endoplasmic Reticulum

An organelle comprised of two continuous structures, primarily responsible for fatty acid and protein synthesis

Smooth Endoplasmic Reticulum

A section of the ER that contains enzymes associated with fatty acid synthesis as well as stores and releases calcium

Rough Endoplasmic Reticulum

A section of the ER that is adhered with ribosomes, acting as a site for protein synthesis for proteins distributed to other organelles or secreted

Golgi Apparatus

An organelle with polar faces that modifies and sorts proteins arriving from the rough ER and distributes them to other organelles or the cell membrane for secretion

Endosome

An organelle comprised of a small, membrane bound vesicle that sorts and organizes vesicular movement and traffic in the cell, carrying and moving objects within

Lysosome

An organelle that acts as the cell’s “stomach”, containing digestive enzymes to recycle and break down parts required to maintain the body’s defence systems

Peroxisome

An organelle that acts as the cell’s “reprocessing plant”, containing oxygen-consuming enzymes to break down substances toxic to the body into a form that is safe

Mitochondria

An organelle that transfers the energy present in nutrients into ATP via cellular respiration

Cytoskeleton

An organelle that is a network of protein filaments throughout the cell used to structurally support the cell, facilitate changes in cell shape, and produce cell movement

Actin Filament

A cytoskeleton protein filament formed from the assembly of globular actin proteins into two twisted chains with a role in movement of muscles

Intermediate Filaments

A cytoskeleton protein filament formed from twisted strands of multiple proteins (keratin, desmin, laminin, etc.) involved in the formation and structure of cell junctions

Microtubules

A cytoskeleton protein filament formed as a hollow tube made from globular tubulin subunits that allow motor proteins to move endocytes across the cell

Pathophysiology

The study of how a physiological part of the body changes in function after a disease or injury

Membrane

External amphipathic layers that surround cells and their internal structures

Fluid-Mosaic Model

The model of cell membrane structure stating that the membrane is made up of a phospholipid bilayer, along with membrane proteins and cholesterol

Integral Membrane Protein

A class of membrane protein embedded in the membrane or spanning the membrane

Peripheral Membrane Protein

A class of membrane protein that lies on a membrane surface (primarily cytosolic surface) bound to polar regions of integral membrane proteins

Desmosome

A type of cell junction that forms dense plaques between cells to give structural integrity to the cell

Tight Junction

A type of cell junction that forms a band around entire cells to create a barrier that prevents liquid and material leaks

Gap Junction

A type of cell junction that forms a pore between cells to allow passage of ions and small molecules