Organelles Flashcards
What is the Cell Membrane?
a delicate thin phospholipid bio-layer that encloses the cytoplasm in in all cells.
What does the Cell Membrane control?
The Cell Membrane controls the movement of substances into and out of the cell (selective permeability). It is responsible for recognition, adhesion and chemical communication between cells.
What is a Cell Wall?
The Cell Wall is a non-living, cellulose structure outside the cell membrane. It is only found in plant cells!
What does the Cell Wall control?
The Cell Wall provides support, prevents expansion of the cell, and allows water and dissolved substances to pass freely through it.
What are Centrosomes?
Centrosomes are structures found inside of cells. They are made from two centrioles (remember mitosis).
What do centrosomes do?
The main purpose of a centrosome is to organize microtubules and provide structure for the cell, as well as work to pull chromatids apart during cell division (mitosis).
What is cytoplasm?
The jelly-like fluid that fills a cell is called cytoplasm It is made up of 90% water and salt and contains ions, salts, enzymes and food molecules. Cytoplasm is present within the cell membrane of all cell types and contains all organelles and cell parts
What is the Endoplasmic reticulum (ER)
a network of intracellular membranes (called phospholipid bilayers - same as in the cell membrane). It is involved with the production, processing, transport and storage of materials within the cell.
Where is the Ednoplasmic reticulum located?
It it located next to the nucleus
What are the two types of ER?
Rough ER and smooth ER
What does the rough ER do?
Covered in ribosomes = involved in the synthesis and packaging of proteins
What does the smooth ER do?
no ribosomes (so smooth) = contains enzymes that help with the creation of important lipids, detoxifying substances (what turns alcohol into not alcohol), and stores ions that the cell may need later on (e.g. sodium ions are used for energy in muscle cells)
What is the Golgi Apparatus?
a stack of flat membrane sacs where the final synthesis and packaging of proteins into membrane-bound vesicles occurs before they are secreted from the cell. It is linked to the ER.
What does the Golgi Appartus do?
It processes proteins and packages up and sends them where they need to go
Made up of stacks of membranous layers that are called the Golgi body
In city analogy, it is the post office
What are lysosomes?
They are membrane-bound vesicles that contain powerful enzymes
What do lysosomes do?
They break down debris and foreign material = in city analogy it is the waste department
What is the mitochondria?
composed of folded layers of membrane
What does mitochondria do?
Energy is transformed and released for use by the cells. - it converts sugar, carbohydrates and fats into ATP
What does the nucleus contain?
The genetic information for the cell
What is the nucleolus? What makes it different from other organelles?
Located inside the nucleus - it is the only organelle that isn’t enveloped within its own membrane
What does the nucleolus do?
Main job is makes ribosomal RNA, or messenger rRNA, which it then combines with some proteins to form the basic units of ribosomes
What are ribosomes?
tiny organelles located in the cytosol, sometimes associated with endoplasmic reticulum.
What do ribosomes do?
Convert mRNA into proteins and amino acids
What are vacuoles?
membrane-bound and found in most cells in variable numbers.
What do vacuoles do?
They may contain food, enzymes or fluid.
What is the difference between plant vacuoles and animal vacuoles?
Plant cells typically have large fluid-filled vacuoles that provide physical support whereas those in animal cells, if they are present, tend to be quite small.
What do vesicles do?
transport items in and out of the cell
