Organelles

Structure

• double membrane (envelope) binds it
• nuclear pores allow mRNA and ribosomes out
• DNA loose inside nucleus as chromatin
• nucleoplasm is granular material

Function

• to contain codes for protein synthesis

Structure

• darker staining region of nucleus
• heterochromatin is densely packed
• euchromatin is less densely packed (lighter coloured)

Function

• synthesis of rRNA and ribosomes

Structure

• parallel double membranes form fluid-filled sacs: cisternae
• cisternae are studded with ribosomes
• cisternae sacs are interconnected
• membranes continue from nuclear envelope

Functions

• to transport materials through the cells
• transport proteins made by the ribosomes
• synthesise proteins (ribosomes' role)

Structure

• cisternae interconnected
• continuous of rough endoplasmic reticulum
• no ribosomes

Function

• synthesis and transport of lipids and steroids

Structure

• made of a large subunit atop a smaller subunit
• no membrane
• two tRNA attachment sites

Functions

• protein synthesis
• site where mRNA is translated and polypeptide formed

Structure

• series of separate, flatterened fluid-filled sacs: cisternae
• made of transport vesicles which fuse together and then pinch off later

Functions

• production and packaging of secretory enzymes
• making lysosomes, glycoproteins - modification of proteins from the rER
• transport and storage of lipids
• secreting carbohydrates

Structure

• cylindrical to enable large surface area to volume ratio, generslly 1-10 micrometers
• organic matrix solution contains lipid/protein compounds
• the double membrane is separated by inter-menbrane space, and the inner membrane folds into cristae
• ribosomes present (70S or small) and a circle or DNA

Function

• to produce ATP in aerobic respiration, which is the molecule used to release energy

Structure

• small, temporary vacuoles with one membrane surrounding enzymes

Function

• to isolate harmful enzymes which are released to repurpose old organelles
• ingesting bacteria isolated by white blood cells in phagocytosis

Structure

• ring of nine microtubule triplets. microtubules are hollow cylinders
• come in pairs ( a centrosome), at right angles to each other

Functions

• organise the spindle (microtubules) during cell division
• NOTE - only found in animal cells (some protoctistans too), and one centrosome per cell

Structure

• contains stroma (fluid) bound by a double membrane (envelope)
• like the mitochondria, has 70S ribosomes in the stroma and circular DNA
• thylakoids are the flattened sacks holding pigments (eg chlorophyll)
• stack of thylakoids = a granum (plural: grana) 
• also has starch grains

Function

• to trap light energy (hence large thylakoid surface area) for photosynthesis

Structure

• membrane that binds it is the tonoplast
• filled with sap/solution

Function

• to store cell sap solution which may contain glucose, amino acids, minerals)
• in plants it has a supportive role in the cell structure

Structure

• cells have pores called cell pits
• plasmodesmata are strands of cytoplasm through the cell pits

Functions

• transport of nutrients between plant cells
• the symplast (plasmodesmata network) is important in water transport