Organelle structure description Flashcards
Nucleus
Largest organelle
When stained shows darkened patches known as chromatin
Surrounded by nuclear envelope
Numerous holes called nuclear pores around the envelope
Inside this organelle is a dense sphere structure called the nucleolus
Endoplasmic reticulum
Series of flattened membrane bound sacs called cisternae Continues with outer nuclear envelope Two types Rough is studded with ribosomes Smooth is not studded with ribosomes
Golgi apparatus
Consists of a stack of membrane bound flattened sacs
Not stable structure, constantly changing
Mitochondria
Spherical or sausage shaped
2 membranes separated by fluid filled space
Inner membrane highly folded to form cristae
Central part of the organelle is called the matrix
Chloroplasts
Only found in plant cells, and some in protoctists
2 membranes separated by fluid filled space
Inside the organelle there are flattened membrane sacs called thylakoids
Stack of thylakoids is called a granum
Organelle often contains starch grains
Lysosomes
Spherical sacs surrounded by a single membrane
Contain powerful digestive enzymes
Vacuole
Largest central organ found in plant cells
Filled with water and solutes so it presses the cytoplasm against the cell wall
Vesicles
Membrane bound sacs
Ribosome
Tiny
Found in cytoplasm, as well as bound to endoplasmic reticulum
Made of 2 subunits
Centrioles
Small tubes of protein fibres (microtubules)
Pair of them next to the nucleus in animal cells
Cilia and flagella
Hair like extensions which stick out from cell
Each one made up of a cylinder
Cylinder contains 9 microtubules in a circle, and 2 microtubules in a central bundle
Cytoskeleton
Describes network of protein fibres found inside a cell
Proteins included are actin and tubulin
Plant cell wall
Outside of plant cells plasma membrane
Made of cellulose
