Cell structure Flashcards
Describe the structure and roles of the Cell wall
- Gives Plants strength, support and structure
- Made of cellulose
- can Function as a carbohydrate store
Describe the structure and roles of the Nucleus
- Largest organelle
- Controls the cell
- Contains the genetic
information
Describe the structure and roles of the Nuclear envelope
- A double membrane that surrounds the nucleus
- Contains pores that allow larger substances to enter/exit the nucleus
Describe the structure and roles of the Nucleolus
- Densely stained region where ribosomal RNA is produced
Describe the structure and roles of the Mitochondria
- Energy-generating organelle
- Surrounded by two membranes that fold to form cristae
- Cristae project into a liquid called the matrix
- 2-5um long
Describe the structure and roles of the Chloroplast
- Surrounded by a double membrane.
- Filled with a liquid called stroma
- Contains sacks of thylakoid membranes called grana
- 6-10um long
Describe the structure and roles of the Vacuoles
- Membrane is called the tonoplast
- Filled with a cell sap
- Important in keeping the cell firm
Describe the structure and roles of the RER
- Forms flattened sacs called cisternae which are double membraned
- Is the site of protein synthesis due to the presence of ribosomes
Describe the structure and roles of the SER
- site of lipids, steroids and cholesterol production
- Contains enzymes
Describe the structure and roles of the Ribosomes
- Made in the nucleus
- Two separate units
- Some remain free while others attach to ER
- Site of protein production
- 20nm
Describe the structure and roles of the Golgi Apparatus
- Stack of flattened double membrane cisternae
- Modifies, sorts and packages molecules ready for transport
- Opposite ends the sacs give off vesicles
Describe the structure and roles of the lysosomes
- Responsible for breaking down unwanted organelles and foreign matter
- Sacs surrounded by a single membrane
- Low pH
- Contain digestive enzymes
Describe the structure and roles of the Centrioles
- Produce mitotic spindle for cell division
- Involved in formation of cilia and undulipodia
- Made of tubulin forming bundles of microtubules
- 0.4um long
Describe the structure and roles of the Cytoskeleton
- Maintains shape and stability
- Allows substances and organelles to move within the cell and the cells itself to move
- Two types: actin filament (7nm) and microtubules (20 - 30nm)
Describe the structure and roles of the Cilia and undulipodia
- Arranged in the 9 + 2 formation
- Cilia are short and abundant on cells
They beat rhythmically - < 10um
- Undulipodia are long and singular
- Cause the cell to move
