B2.2 Organelles and Compartmentalization

Organelle

specialized structure that performs important specific cellular functions within a cell

cell fractionation

technique in which cells are broken into pieces and the different cell parts are separated

ultracentrifugation

The second stage of cell fractionation when the fragments in filtered homogenate are separated in a machine called a centrifuge.

Plasma membrane

A selectively-permeable phospholipid bilayer forming the boundary of the cells

homogenization

when trying to separate cell organelles, a tissue containing cells is blended in a cold buffered solution isotonic to the cell cytoplasm

nucleus

double membrane organelle where transcription and production of mRNA takes place

cytoplasm

A jellylike fluid inside the cell in which the organelles are suspended

Transcription

(genetics) the organic process whereby the DNA sequence in a gene is copied into mRNA. occurs in the nucleus of eukaryotic cells

translation

(genetics) the process whereby genetic information coded in messenger RNA directs the formation of a specific protein at a ribosome in the cytoplasm

metabolites

chemical products of metabolism

enzymes

Proteins that speed up chemical reactions

Lysosomes

single membrane bound cell organelle filled with enzymes needed to break down certain materials in the cell

phagocytosis

process in which extensions of cytoplasm surround and engulf large particles and take them into the cell

phagocytic vacuole

forms when microbe is engulfed and will fuse with a lysosome

mitochondria

a double membrane bound organelle found in large numbers in most cells, in which the biochemical processes of respiration and energy production occur.

Cytoskeleton

network of protein filaments within some cells that helps the cell maintain its shape and is involved in many forms of cell movement. Not considered an organelle

Chloroplast

a double membrane bound organelle found in plant and algae cells where photosynthesis occurs

ribosome

organelle not bound by a membrane that is the site of protein synthesis

cell wall

not considered an organelle - outside of a plant cell. rigid structure made of cellulose that surrounds the cell membrane and provides support to the cell

flagella

membrane bound organelle that allows for movement of cells

Organelles with no membrane

Ribosomes

Free DNA in prokaryotes

Microtubules

Organelles with single membrane

Rough and smooth eR

Vacuole and Vesicles

Lysossomes

Golgi Apparatus

Organelles with double membrane

Chloroplasts

Mitochondria

Nucleus

Amyloplasts

Chromoplasts