Chapter 6: The Endomembrane System and Cellular Components

These flashcards cover the key vocabulary related to the endomembrane system and cellular structures as presented in the lecture notes.

Endomembrane System

A set of membranous organelles that interact with each other via vesicles.

Vesicle

A structure that naturally forms during the processes of secretion, uptake, and transport of materials, enclosed by a lipid bilayer.

Endoplasmic Reticulum (ER)

A membranous network in the cytoplasm consisting of the RER and SER, providing a large surface area.

Rough Endoplasmic Reticulum (RER)

Endoplasmic reticulum embedded with ribosomes, which insert proteins into the ER lumen as they are synthesized.

Smooth Endoplasmic Reticulum (SER)

Endoplasmic reticulum that does not have ribosomes and is the primary site of lipid synthesis.

Golgi Apparatus

A stack of flattened membrane sacs called cisternae where proteins are processed, modified, and sorted.

Lysosomes

Small membrane-bound sacs containing digestive enzymes, used to degrade ingested material and damaged organelles.

Vacuole

Large membrane-bound sacs that perform many functions, particularly in plants, storing water, food, and waste.

Peroxisomes

Membrane-bound organelles that contain enzymes to break down hydrogen peroxide, protecting the cell.

Mitochondria

Organelles where aerobic respiration occurs, generating ATP from chemical energy.

Chloroplasts

Organelles in plants and algae that carry out photosynthesis, containing chlorophyll.

Endosymbiont Theory

Proposed theory stating that mitochondria and plastids evolved from prokaryotic cells.

Cytoskeleton

A dense network of protein fibers providing structural support, aiding in organelle positioning, cell movement, and transport of materials.

Microtubules

The thickest filaments of the cytoskeleton, made of tubulin dimers, involved in cell shape and organelle movement.

Microfilaments (Actin Filaments)

Solid filaments made of actin monomers, important in muscle contraction and cell movement.

Intermediate Filaments

Cytoskeletal components made of various proteins, providing structural stability to cells that withstand mechanical stress.

Extracellular Matrix (ECM)

A gel of carbohydrates and fibrous proteins outside the plasma membrane, providing structural support and facilitating cell communication.

Cell Wall

A rigid layer found outside the plasma membrane in plants and fungi, providing structure and support.