Structure of eukaryotic cells

• The rough endoplasmic reticulum (RER) translates and distributes proteins.
• Ribosomes structure to function:

  • Large sub unit
  • Small sub unit
• Smooth endoplasmic reticulum (SER) structure to function:

  • Has a layered membrane of fluid filled sacs (cisternae)
  • Increases surface area and improves efficiency
  • Tube like structure
• The smooth endoplasmic reticulum synthesizes and distributes carbohydrates and lipids
• Rough endoplasmic reticulum adapted to their function:

  • Contains many ribosomes which increases its surface area
  • They also contain cisternae within their structure
• The mitrochondria releases energy in the form of ATP and has its own DNA to create enzymes to speed up respiration.
• Mitrochondria structure to function:

  • Inner membrane is folded into cristae
  • Matrix makes its own DNA
• Exocylsis is when the vesicle fuses with the membrane and releases its contents
• Lysosomes have many functions:

  • Hydrolise pathogens
  • Releases its enzymes
  • Digest worn out cells
  • Completely breaks down dead cells
• Lysomes contain a hydrolytic enzyme called lysozymes and are spherical in shape.
• A golgi visacle is what a protien that has been modified by the golgi apparatus is called.
• Function of golgi apparatus:

  • Modifies proteins and lipids
  • Labels and sorts molecules to where they are needed
  • Once sorted they are distributed from the trans face
• The trans face receives modified proteins which are released back into the cell.
• The cisternae in the golgi apparatus is where the protein is modified, sorted and labeled.
• The cist face receives the translated protien coming from either the cytoplasm or RER
• The golgi apparatus is made of:

  • A collection of folded cisternae
  • These are broken down into components which make up the cist and trans face
• The 3 main features of chloroplasts:

  • Chloroplast envelope surrounds the chloroplast and controls what can enter and leave the chloroplast
  • The grana is stacks of disks called thylakoids, which is where light absorption happens
  • The stroma the synthesis of sugar happens here
• Chloroplast structure to function:

  • The granal membrane provides a large surface area for light absorption to happen effieciently
  • The fluid in the stroma processes enzymes to make sugars
  • Contains both DNA and ribosomes to quickly and easily manufacture proteins needed for photosynthesis
• The vacuole is a fluid filled sac bound by a single membrane, which is called the tonoplast.
• Plant vacuoles functions:

  • They support herbacous plants and herbacous parts of woody plants due to their rigid structure
  • The sugars and amino acids within the cell sap act as a temporary food source
  • The pigment called anthocyanins can colour petals and attract pollinating insects
• Vacuole structure to function:

  • A large amount of cell sap is contained providing a large area of temporary food storage
  • Rigid structure helps protect the cell
  • Takes large amount of space in a plant to help protect large area of space
• The cell wall contains microfibrills embedded in a matrix. These cellulose structures are strong and contribute this to the cell
• Cell wall functions:

  • Provide mechanical strength which stops the cell from bursting under pressure during osmosis
  • Allow water to pass through it and contribute to the movement of water through the plant
  • To provide mechanical strength to the plant as a whole
• Cell wall structure to function:

  • They consist of many polysaccharides such as cellulose
  • The middle lamella which marks the boundary and cements adjacent cells together
• Whilst a plant cell wall is made of cellulose, algae cell walls can be made from either cellulose, glycoproteins or a mixture of both and fungi cell walls are made from a mixture of polysaccharides containing nitrogen called chitin
• The cell membrane controls the entry and exit of material, primarily it is made of phospholipids.
• The cytoplasm is a jelly like substance that contains enzymes and other soluble materials
• Ribosomes synthesis polypeptides, bacteria contains the 70S type.
• The cell membrane controls the entry and exit of material. It is primarily made of phospholipids.
• Select the three statements that best describe prokaryotic cells

  Some have a capsule

  Contain no membrane bound organelles

  May have circular DNA strands called plasmids
• What structure within the nucleus is responsible for synthesizing ribosomes

  Nucleolus
• Which two organelles contain their own DNA and ribosomes

  Mitrocondria

  Chloroplasts
• Suggest two organelles that phagocytes might have numerous / well developed of.

  Golgi apparatus

  Lysosomes
• Where in chloroplasts does light independent stage of photosynthesis occur

  Stroma