Organelles Flashcards
All organelles are membrane-bound meaning that they are…
…made from phospholipid bilayers
What are organelles?
Distinct, internal compartments of cells
What hold the organelles together?
Protein filaments that form the cytoskeleton
The cytoskeleton is formed by three components:
Microtubules
Microfilaments
Intermediate filaments
The three components together combine to assist in:
maintaining the shape of the cell
providing a support structure for organelles (like a scaffold)
the movement of materials (e.g. lysosomes) within a cell
movement of the cell itself if required (e.g. how amoebas move)
What does the plasma membrane do?
controls movement of substances in and out of cell
What is the cytosol?
jelly-like, intracellular fluid
water with many dissolved substances
What is the cytoplasm?
cytosol + organelles
(but NOT including the nucleus)
What is the nucleus?
Enclosed in a double membrane – the nuclear envelope
Contains the genetic material of cell (DNA)
DNA found in chromosomes
Nucleus contains nucleoli – large aggregations of RNA molecules
What is the mitochondria?
Source of chemical energy for the cell by producing adenosine triphosphate (ATP)
Enclosed in a double membrane
Inner membrane is highly folded
ATP is produced during cellular respiration, which occurs within these folds
What is the ribosome?
Made from protein and ribosomal RNA (rRNA)
Function is protein production
Found in cytosol as well as attached to the endoplasmic reticulum
Is ribosome is an organelle?
No it is not and isn’t enclosed in a nuclear membrane
What is the endoplasmic reticulum?
Channels formed by membranes
Used to transport material within cells
What is the rough E.R ?
They are very important in the synthesis and packaging of proteins. Some of those proteins might be used in the cell and some are sent out. The ribosomes are attached to the membrane of the ER.
What is the Smooth E.R?
It synthesizes lipids, phospholipids, and steroids. Cells which secrete these products, such as those in the testes, ovaries, and skin oil glands have a great deal of smooth endoplasmic reticulum.
