Eukaryotic Structure and Function

• The nucleus contains nuclear pores, which are holes in the nuclear membrane.
• The nucleus also contains a nuclear envelope, which has an outer and inner membrane.
• The nucleolus is a smaller sphere inside the nucleus where ribosome production occurs.
• Nucleoplasm is a granular, jelly-like substance found in the nucleus.
• Chromosomes are protein-bound, linear DNA found in the nucleus.
• The function of the nucleus is to serve as the site of DNA replication, contain the genetic code for each cell, control cellular processes such as gene expression and determine specialisation, and it is also the site of mRNA transcription, mitosis and semi conservative replication.
• what is the structure of the Smooth Endoplasmic Reticulum? SER has Folded membranes called cisternae.
• what is the function of Smooth Endoplasmic Reticulum. The function is the Synthesis and storage of lipids and carbohydrates
• what is the structure of the rough Endoplasmic Reticulum?

  Folded membranes called cisternae and also has Ribosomes on the cisternae.
• What is the Function of the Rough Endoplasmic Reticulum?

  Protein Synthesis, takes place on the ribosomes
• Structure of Mitochondria: double membrane. The inner membrane is folded to make cristae. Fluid centre called the mitochondria matrix. Has it's own loop of DNA
• Mitochondria Function: Site aerobic respiration and site of ATP production.
• Structure of lysosomes: a membrane bound organelle that contains bags of digestive enzymes - 50 different enzymes.
• Function of Lysosomes: hydrolyse phagocytic cells, completely break down dead cells, Exocytosis releases enzymes to outside of cell to destroy material, digest worn out organelles for reuse of materials.
• Structure of the Golgi Apparatus: Folded Membranes called cisternae and Secretary Vesicles pinch off from the Cisternae
• Function of Golgi Apparatus: Receives proteins from RER, Modifies proteins and lipids before packaging them into Golgi Vesicles
• Structure of Ribosomes: Ribosomes are composed of two subunits, a small subunit 70s (prokaryotic) and a large subunit 80s (eukaryotic).
• Function of Ribosomes: Site of protein synthesis, where proteins are made
• Structure of Vacuole (plants only): Filled with fluid. surrounded by a single membrane called a tonoplast.
• Function of a Vacuole: Make cells turgid to provide support. Temporary store of sugars and amino acids. Pigment may colour petals to attract pollinaters.
• Structure of Vesicles: A vesicle is a membrane-bound structure that contains a small amount of material.
• Function of Vesicle: Finished products are transported by vesicles to cell surface where they fuse with the membrane and the contents is released.
• Structure of Chloroplasts (plants only): double membrane, contains thylakoids (plural = granum), folded membranes embedded with proteins and chlorophyll (pigment). Fluid filled stroma contains enzymes for photosynthesis.
• Structure of the Cell wall (plants only): made of microfibrils of the cellulose polymer. In Fungi the cell wall is made of chitin, a nitrogen containing polysaccharide.
• Function of the Cell Wall: Provides structural support and protection to the cell.
• Structure of The cell surface membrane: 'Fluid mosaic’ phospholipid bilayer. Containing embedded proteins and receptors, which could be glycoproteins or glycolipids, and cholesterol.
• Function of The cell surface membrane: controls the entrance and exit of molecules

  • isolates cytoplasm from extracellular activity
  • selectively permeable to regulate transport of substances
  • involved in cell signalling/cell recognition