3.3 Structure of an Epithelial Cell Flashcards
What is the ultrastructure of a cell?
The internal structure of a cell that suits it for its job.
What type of cell is an epithelial cell?
Eukaryotic
What do eukaryotic cells have that prokaryotic cells don’t?
A distinct nucleus and membrane-bound organelles.
What is the function of an epithelial cell?
The absorb and secrete.
What is the most prominent feature of a eukaryotic cell?
The nucleus
What is the nuclear envelope?
A double membrane that surrounds the nucleus. It controls the entry and exit of materials in and out of the nucleus, and contains reactions within it.
What are nuclear pores?
They allow the passage of large molecules out of the nucleus.
What is nucleoplasm?
A granular, jelly-like material that make sup the bulk of the nucleus.
What is chromatin?
The DNA found within the nucleoplasm.
What is the nucleolus?
A small, spherical body within the nucleoplasm. It manufactures ribosomal RNA and assembles ribosomes.
What are 3 functions of the nucleus?
To act as the control centre of the cell through the production of mRNA and hence protein synthesis.
To retain the genetic material of the cell.
The manufacture ribosomal RNA and ribosomes.
What 3 structure make up mitochondria?
A double membrane
Cristae
The matrix
What is the double membrane?
It surround the mitochondria, the outer membrane controls the entry and exit of material. The inner membrane is folded to form the cristae.
What is the cristae?
Shelf-like extensions of the inner membrane. They provide a large surface area for the attachment of enzymes involved in respiration.
What is the matrix?
This makes up the remainder of the mitochondria. It is a semi-rigid material that contains protein, lipids and traces of DNA. The enzymes involved in respiration are in the matrix.
What is the mitochondria responsible for producing?
ATP, from carbohydrates
What are the two types of endoplasmic reticulum?
Rough ER and Smooth ER
What does the RER have that the SER doesn’t?
Ribosomes on its surface.
What are the RER’s two functions?
To provide a large surface area for the synthesis of proteins and glycoproteins.
To provide a pathway for the transport of materials, especially proteins, throughout the cell.
What are the SER’s two functions?
To synthesise, store and transport lipids and carbohydrates.
Where does the Golgi apparatus occur?
In nearly all eukaryotic cells.
What structure is it similar to?
The SER, except it is more compact.
What does it consist of?
A stack of membranes that make up the cisternae, with small rounded hollow structures called vesicles.
What are the 5 functions of the Golgi apparatus?
Add carbohydrates to proteins to form glycoproteins Produce secretory enzymes Secrete carbohydrates Transport, modify and store lipids Form lysosomes
