Plant and Animal Cell Organelle Unit 4

Nucleus

Command center of the cell; contains DNA and controls cell activities

Nucleolus

Region that produces subunits of ribosomes

Nuclear envelope

Double membrane with pores that encloses the nucleus

Ribosomes

Particles that carry out protein synthesis

Rough endoplasmic reticulum (Rough ER)

Studded with ribosomes; processes and modifies proteins

Smooth endoplasmic reticulum (Smooth ER)

Lacks ribosomes; synthesizes lipid molecules

Golgi apparatus

Processes, packages, and secretes modified proteins

Vesicle

Small membrane-bound sac that stores and transports substances

Peroxisome

Vesicle that breaks down fatty acids and produces hydrogen peroxide

Mitochondrion

Organelle that carries out cellular respiration, producing ATP molecules

Cytoplasm

Semifluid medium that contains organelles

Plasma membrane

Surrounds cytoplasm; regulates entrance and exit of molecules

Centrioles

Short cylinders of microtubules that help organize cell division in animal cells

Cytoskeleton

Maintains cell shape and assists movement of cell parts

Actin filaments

Protein fibers that play a role in cell movement and shape

Intermediate filaments

Protein fibers that provide support and strength

Microtubules

Cylindrical structures that move organelles and maintain cell shape

Lysosome

Vesicle that digests macromolecules and cell parts (mostly in animal cells)

Polyribosome

String of ribosomes simultaneously synthesizing the same protein

Cell wall

Outer surface that shapes, supports, and protects the cell

Central vacuole

Large, fluid-filled sac that stores metabolites and helps maintain turgor pressure

Chloroplast

Carries out photosynthesis, producing sugars

Plasmodesmata

Channels between plant cell walls for transport and communication