Biology

• Cell ultrastructure


  All the parts that make up a cell
• Cell wall


  Structure surrounding a cell that protects and helps the cell to keep its shape
• Cell membrane


  Controls what enters and leaves the cell (it is selectively permeable)

  
• Selectively permeable


  Only certain molecules can pass through
• Chloroplast


  Small green discs in plant cells where photosynthesis takes place
• Cytoplasm


  The jelly inside a cell where the organelles are found
• Nucleus


  Contains genetic information (DNA)
• Ribosome


  Site of protein synthesis
• Mitochondria


  Site of aerobic respiration
• Organelle


  Any part of the cell found in the cytoplasm

  
• Fungal cell


  The cell type found in fungi
• Cellulose


  The chemical that makes up plant cell walls
• Vacuole


  A structure found in the cytoplasm that contains cell sap in plants
• Cell wall


  Supports and strengthens cell
• Cell membrane


  Controls what substances enter and leave a cell
• Cytoplasm


  The fluid inside the cell membrane where many chemical reactions happen including fermentation
• Mitochondria


  The site of aerobic respiration where most ATP is produced
• Chloroplasts


  The site of photosynthesis where sugar is produced
• Vacuole


  A compartment in the cell that stores water and helps keep the cell turgid
• Ribosomes


  The site of protein synthesis (where the amino acids are joined together)
• Plasmids


  Small circular DNA molecules that contain genes
• Nucleus


  A compartment in the cell where DNA is stored as chromosomes
• Plant cell walls are made from cellulose
• Fungal cell


  • Yeast cells are an example of a fungus. They are similar to plant and animal cells but they have a different cell wall structure.
• Bacterial cell


  • Bacterial cells do not have a nucleus. Their DNA floats around in the cytoplasm as a large circular DNA molecule. They also lack a number of other organelles found in the other cell types. Their cell walls are also different to plant and yeast cells.

  
• Cell membrane


  The structure that controls movement of molecules into and out of a cell
• Phospholipids


  Molecules that make up the cell membrane with proteins
• Selectively permeable


  Allows some molecules through but not others
• Passive transport


  Movement of molecules that does not require energy
• Concentration gradient


  When there is a difference in concentration on each side of a cell membrane
• Diffusion


  The movement of molecules from higher concentration to lower concentration, down a concentration gradient
• Osmosis


  The movement of water from higher water concentration to lower water concentration, through a selectively permeable membrane
• Turgid


  A plant cell that has filled up with water
• Plasmolysed


  A plant cell that has shrunk as water moved out of it
• Active transport


  The movement of molecules and ions against the concentration gradient that requires energy
• Passive transport occurs down a concentration gradient and does not require energy
• Diffusion


  An example of passive transport, the movement of molecules down a concentration gradient from a higher to a lower concentration
• The cell membrane consists of phospholipids and proteins and is selectively permeable
• Osmosis is another example of passive transport
• Animal cell placed in salty/sugary solution


  Shrinks, water moves out of the cell by osmosis