cell ultrastructure

• What is the primary function of the nucleus in a cell?


  Acts as the control centre of the cell
• What does the nucleus retain in the cell?

  The genetic material of the cell in the form of DNA and chromosomes
• What is manufactured in the nucleus?

  RNA and ribosomes
• What is the structure of the nuclear envelope?


  A double membrane surrounding the nucleus, perforated by pores
• What is the function of the pores in the nuclear envelope?

  Enable communication between the nucleus and the cytoplasm
• What is the role of the nucleolus?

  Stores the cell’s RNA and is important in the production of ribosomes
• Where is the nucleolus located?

  In the nucleus and is not surrounded by a membrane
• What is the primary function of mitochondria?

  The site of energy producing reactions within the cell - aerobic respiration
• What is the typical shape of mitochondria?

  Usually rod-shaped
• What are the main components of mitochondria?

  Double membrane, cristae, and the matrix
• What characterizes the rough endoplasmic reticulum?

  Its surface is dotted with ribosomes
• What is the function of ribosomes on the rough endoplasmic reticulum?


  Create, store, and transport proteins
• How does the rough endoplasmic reticulum contribute to protein synthesis?

  Provides a large surface area for the synthesis of protein
• What role does the rough endoplasmic reticulum play in material transportation?

  Provides a pathway for the transportation of materials, especially proteins, around the cell
• What is the primary function of the smooth endoplasmic reticulum?

  Synthesizes, stores, and transports lipids and carbohydrates
• What substances does the smooth endoplasmic reticulum help to create?

  Steroids
• What is the structure of the Golgi apparatus?

  A group of smooth endoplasmic reticulum containing a series of flattened sacs
• What are the functions of the Golgi apparatus?

  Makes lysosomes, produces secretory enzymes, and transports, modifies, and stores lipids
• What is the function of vesicles?


  Transports substances to and from the outside of the cell via the plasma membrane
• What do lysosomes contain?

  Digestive enzymes that digest invading cells and destroy cells when they need to be replaced or die
• What is the role of lysosomes in the cell?

  Release enzymes to the outside of the cell
• What is the function of the cell/plasma membrane?


  Separates the interior from the outside environment
• How does the cell/plasma membrane control substances?

  Controls what enters and exits the cell
• What is the role of cilia in a cell?

  Help substances move along the surface
• What do cilia contain that allows them to move?

  Microtubules
• What is the function of the cytoskeleton?

  Supports the cell membrane and gives the cell its shape
• How does the cytoskeleton help organelles?

  Helps to correctly position organelles
• What are the components of the cytoskeleton?

  Made from microtubules, actin filaments, and intermediate filaments
• What is the primary function of ribosomes?

  The site of protein synthesis
• What are microtubules?


  Very small, hollow cylinders
• What is the role of microtubules in the cell?

  Act as a guide for moving organelles
• How do microtubules assist during cell division?

  They grow fibres which attach onto chromosomes to pull apart the replicated chromosome
• What are centrioles?


  Small, hollow cylinders containing a ring of microtubules
• What is the function of centrioles during cell division?

  Involved with separation of chromosomes
• What are peroxisomes?


  Single membrane that contains digestive enzymes for breaking down toxic materials
• What is the role of peroxisomes in the cell?

  Helps to remove toxic substances
• What do peroxisomes hold onto?

  Enzymes that require oxygen
• What type of cells are plant and animal cells classified as?

  Eukaryotic
• What type of cells are bacteria classified as?

  Prokaryotic
• What is the basic unit of life?

  Cells