Cell Organelle Functions and Structures

Cell Organelle Function & Structures

Plasma membrane - Structure

Lipid bilayer with scattered proteins and cholesterol molecules

Plasma membrane - Function

Maintains boundary of cell and integrity of cell structure; embedded proteins serve multiple functions

Nucleus - Structure

Surrounded by double-layered nuclear envelope

Nucleus - Function

Houses the DNA, which dictates cellular function and protein synthesis

Nucleolus - Structure

Dark oval structure inside the nucleus

Nucleolus - Function

Synthesis of ribosomal RNA

Cytosol - Structure

Gel-like fluid

Cytosol - Function

Cell metabolism, storage

Rough endoplasmic reticulum - Structure

Continuous with the nuclear envelope; flattened sacs dotted with ribosomes

Rough endoplasmic reticulum - Function

Protein synthesis and post-translational processing

Smooth endoplasmic reticulum - Structure

Tubular structure continuous with rough endoplasmic reticulum; without ribosomes

Smooth endoplasmic reticulum - Function

Lipid synthesis and post-translational processing of proteins; transport of molecules from endoplasmic reticulum to Golgi apparatus; calcium storage

Golgi apparatus - Structure

Series of flattened sacs near the endoplasmic reticulum

Golgi apparatus - Function

Involved in post-translational processing; packaging and sorting of proteins

Mitochondria - Structure

Oval-shaped, with an outer membrane and an inner membrane with folds called cristae that project into the matrix

Mitochondria - Function

ATP synthesis

Lysosomes - Structure

Granular, saclike membranous organelle scattered throughout the cytoplasm

Lysosomes - Function

Breakdown of cellular and extracellular debris

Peroxisomes - Structure

Membranous organelles similar in appearance to lysosomes, but smaller

Peroxisomes - Function

Responsible for breakdown of toxic substances, including hydrogen peroxide

Vaults - Structure

Small, barrel-shaped nonmembranous organelles

Vaults - Function

Unknown function; possibly transport of molecules between nucleus and cytoplasm

Ribosomes - Structure

Granular nonmembranous organelles composed of proteins and rRNA; located in cytosol or on surface of rough endoplasmic reticulum

Ribosomes - Function

Translation of mRNA to synthesize proteins

Centrioles - Structure

Two cylindrical bundles of protein filaments that are perpendicular to each other; non-membranous (extra)

Centrioles - Function

Direction of mitotic spindle development during cell division

Cytoskeleton - Structure

Composed of protein filaments, including microfilaments, intermediate filaments, and microtubules

Cytoskeleton - Function

Provides structural support of cell; cell movement and contraction