Eukaryotic cells and organelles

• What does an animal cell contain?

  RER, SER, lysosome, ribosome, Golgi apparatus, cytoplasm, mitochondrion, nucleus, nucleolus, cell surface membrane
• What is plant cell wall made of?

  Cellulose
• Give a description of cell surface membrane. 


  Found on the surface of animal cell and just inside the cell wall of other cells. Mainly made of lipids and proteins.
• What is the function of cell surface membrane?

  Regulates the movement of substances into and out of the cell. Has receptor molecules on it, which allows it to respond to chemicals like hormones.
• Give a description of the Nucleus

  A large organelle surrounded by nuclear envelope (double membrane), which contains many pores. Nucleus contains chromosones called a nucleolus.
• Function of nucleus


  Controls cell activites. DNA contains instructions to make proteins. Pores allows substances (eg RNA) to move between nucleus + cytoplasm . Nucleolus makes ribosomes.
• Give a description of mitochondrion

  Oval shaped, double membrane. Inner membrane folded to form structure called cristae. Inside is matrix, which contains enzymes involved in respiration.
• Function of mitochondrion


  Site of aerobic respiration. Aerobic respiration produces ATP - a common energy source in the cell. Mitochondria are found in large number in cells that are very active and require a lot of energy.
• Description of chloroplast

  Small flattened structure found in plant cells. Surrounded by double membrane and also has membranes inside called thylakoid membranes. These membranes stacked up in some part of chloroplast to form grana. Grana linked together by lamellae - thin flat pieces of thylakoid membrane
• Function of cholorplast

  Site of photosynthesis. Some parts of photosynthesis happen in the grana - other parts happen in the the stroma ( thick fluid found in chloroplasts).
• Description of Golgi Apparatus


  Fluid filled membrane bound flattened sacs. Vesicles are often seen at the edges of the sacs
• Function of Golgi Apparatus

  Processes and packages new lipids and proteins. It also makes lysosomes.
• Description of Golgi Vesicle

  Small fluid filled sac in the cytoplasm, surrounded by a membrane and produced by the Golgi apparatus.
• Function of Golgi Apparatus


  Stores lipids and proteins made by the Golgi apparatus and transports them out of the cell.
• Description of Lysosome

  Round organelle surrounded by a membrane, with no clear internal structure. Its a type of Golgi vesicle.
• Function of Lysosome


  Contains digestive enzymes called lysozomes . These are kept seperate from the cytoplasm by the surrounding membrane. Used to digest invading cells or to break down worn out components of the cell.
• Description of Ribosome


  Small organelle that floats free in cytoplasm - or is attached to the RER. Made up of proteins and RNA. Not surrounded by a membrane
• Function of Ribosomes


  The site where proteins are made
• Description of Rough Endoplasmic Reticulum

  System of membranes enclosing a fluid filled space. Surface covered in ribosomes.
• Function of RER

  Folds and processes proteins that have been made at the ribosomes
• Description of smooth endoplasmic reticulum

  System of membranes enclosing a fluid filled space
• Function of SER

  Synthesises and processes lipids.
• Description of cell wall

  Rigid structure that surrounds cells in plants, algae and fungi. In plants and algae made mainly of cellulose. in fungi made of chitin.
• Function of cell wall

  Supports cells and prevents them from changing shape.
• Description of cell vacuole (plants)

  Membrane bound organelle found in cytoplasm. Contains cell sap - a weak solution of sugar + salts. Surrounding membrane called tonoplast.
• Function of cell vacuole (plants)

  Helps to maintain pressure inside cell and keeps cell rigid - stops plant from wilting. Also involved in isolation of unwanted chemicals inside the cells.
• How are Epithelial cells adapted to absorb food efficiently?

  • Walls of the small intestine have lots of finger like projections called villi. These increase surface area for absorption
  • Epithelial cells on the surface of the villi have folds in their cell surface membranes called microvilli. Microvilli increaese surface area even more
  • They also have lots of mitochondria - to provide energy for the transport of digested food molecules into the cell.