Eukaryotic Cell Organelles

Structure:

• largest organelle enclosed within an envelope (double membrane)
• contains chromosomal DNA which may be extended (euchromatin) or condensed (heterochromatin)
• perforated envelope (possesses pores)
• contains one or several nucleoli

Function:

• DNA codes for the synthesis of proteins in the cytoplasm 
• pores in the envelope allow large molecules in (enzymes) and out (RNA)
• nucleolus synthesises ribosomal RNA and manufactures ribosomes

Structure

• small bodies of protein and rRNA
• found free in cytoplasm or attached to rough endoplasmic reticulum

Function

• site of protein synthesis

Structure

• membrane system of sacs and tubes permeates the cytoplasm
• flattened rough ER - studded with ribosomes
• tubular smooth ER - lacks ribosomes

Function

• proteins made in ribosomes accumulate in the rough ER and passed on to Golgi apparatus
• smooth ER is involved with lipid metabolism

Structure

• stack of membrane-cound sacs (cisternae)
• forming face - has vesicles from the rough ER joining
• mature face - has vesicles pinching off

Function

• dynamic structure in which proteins are modified 
• e.g have carbohydrate attached to form glycoprotein
• packaged into vesicles either for secretion by exocytosis or for delivery elsewhere in the cell

Sturcture

• vesicles which are produced by the Golgi apparatus which contain hydrolytic enzymes

Function

• comine with membrane bound degenerate organelles or ingested particles (e.g. bacteria) to form secondary lysosomes
• hydrolytic enzymes digest the contents

Structure

• sausage shaped
• surrounded by an envelope
• inner membane of which is folded to form cristae
• fluid filled matrix
• several to thousands per cell

Function

• synthesis of ATP by aerobic respiration

Structure

• oviod
• surrounded by an envelope
• elaborate internal membrane system of lamellae with thylakoids stacked into grana
• contain lipid droplets and starch grains
• occur in some plant cells

Function

• site of photosynthesis
• chlorophyll molecules are attached to the lamellae

Structure

• bound by a single membrane
• vesicles are much smaller than vacuoles
• vacuoles are permanent in plant and fungal cells
• membrane of the sap vacuole in plant cells is called the tonoplast

Function

• vesicles may be used for storage and transport of substances
• e.g. transport to and from the cell-surface membrane or within the cytoplasm
• vacuoles are for storage of water and ions

Structure

• tubular
• formed from the protein tubulin
• occur within centrioles (as 9 triplets of microtubues in a circular arrangement) and throughout the cytoplasm
• animal and fungal cells contain a pair of centrioles

Function

• centrioles form the spindle fibres during cell division of animal and fungal cells
• microtubules also form part of the cytoskeleton and allow movement of cell organelles

Structure

• strands of cytoplasm between nighbouring plant cells that pass through pores in the walls

Function

• facilitate transport of materials between adjacent cells in plants