Cellular Organelles

Structure of the nucleus

• Double membrane (nuclear envelope) with pores

• Contains the nucleolus and chromatin (cell’s genes)

• Shape is maintained by the nuclear lamina (inner membranes)

• Found only in Eukaryotic cells

Function of the nucleus

• Stores genetic information

• Synthesis of RNA

• Ribosome subunit assembly

Structure of the Rough ER

Membrane studded with ribosomes attached to nuclear envelope

Function of the Rough ER

• Site of membrane-bound protein and secreted protein synthesis

• Cell compartmentalization

• Channels proteins to transport vesicles

• Attaches carbohydrate to some proteins

Structure of the Smooth ER

• Folded tubelike structure (cisternae)

• Continuous with the nuclear envelope

Functions of the Smooth ER

• Detoxification

• Calcium Storage

• Lipid Synthesis

• Metabolizes carbohydrates

Structure of the Golgi Complex

• Membrane bound structure composed on flattened sacs (cisternae)

Functions of the Golgi Complex

• Receives transport vesicles from the ER

• Folding and chemical modification of synthesized proteins

• Sorts and packages materials into transport vesicles

• Produces lysosomes and secretory vesicles

• Manufactures certain macromolecules

Structure of the Ribosomes

• Composed of rRNA and a protein

• Made up of 2 subunits (one large, one small)

• Can be bound or free (cytoplasmic)

Function of the ribosomes

• Site of protein synthesis

• Free Ribosomes - Produce proteins for use within the cell

• Bound Ribosomes - Produce proteins for export

Structure of the Mitochondria

• Double membrane (outer smooth, inner is highly folded(cristae))

Functions of the Mitochondria

• Site of cellular respiration

• Produces ATP from sugars, Fats, and other fuels

Structure of the Lysosome

• Membrane-enclosed sacs

• contain hydrolytic enzymes (to digest macromolecules)

• Work best in with the acidic environment inside the lysosome

Function of the Lysosome

• Autophagy - recycles the cells own organelles and macromolecules (digestion)

• Programmed cell death - Apoptosis

Structure of all Vacuoles

Membrane-bound sac

Functions of all vacuoles

• Storage and release of macromolecules and cellular waste products

• Derived from the ER and Golgi

Structure of the Chloroplast

• Double outer membrane (thylakoid sac stacked: granum and fluid: stroma)

• Contain chlorophyll (green pigment) and enzymes and electron transport proteins

• Known as a plastid because it holds pigments

Functions of the Chloroplast

• Site of photosynthesis

Structure of the nucleolus

A dense, membrane-less structure within the nucleus

Function of the Nucleolus

• Site of protein synthesis and assembly

Structure of the nuclear membrane

• Double membrane structure

• Perforated with pores

Functions of the Nuclear Membrane

• Forms the boundary between the nuclear contents and the cytoplasm

Function of Transport Vesicles

Carries ER products to the Golgi

Function of Secretory vesicles

• Carries Golgi modified products to the cell membrane

• Fuses with the cell membrane, releasing the contents to the outside of the cell

Function of the Peroxisomes

• Contains enzymes that transfer H from substrates to oxygen producing H2O2

• Detoxifies alcohol

• Contains enzymes that converts H2O2 to H2O and O2

Functions of the Centriole

• Involved in cell division

Structure of the cell membrane

• double layer of phospholipids

Function of the cell membrane

• Allows sufficient passage of oxygen, nutrients, and waste to service the volume of every cell

Structure of the chromatin

• DNA and proteins of chromosomes are together in an uncoiled, dispersed orientation

Function of the Chromatin

• Condenses to form discrete chromosomes as a cell prepares to divide

Components of the endomembrane system

• Nuclear envelope

• Endoplasmic Reticulum

• Golgi

• Lysosomes

• Vacuoles

• Plasma membrane

Function of the Food Vacuole

• Formed by phagocytosis

• Brings food in and connects with lysosome to digest the nutrients, etc.

Functions of the contractile vacuole

• Collects and expels excess water from freshwater protists and other cells

• Prevents from swelling

• Maintains cellular water balance

Functions of Central Vacuole

• Holds nutrients, ions, and water

• Maintains turgor pressure