unit 1

• What is the function of a cell wall?

  It supports, protects and maintains the shape of cell

  
• What type of organisms are cell walls found in?

  Plant, fungi and and bacteria
• What is the function of the mitochondria?

  Site of aerobic respiration

  
• What type of organisms are mitochondria found in?

  Plant, animal and fungi
• What is the function of chloroplasts?

  Site of photosynthesis

  
• What is the name of the green pigment found in chloroplasts?

  Chlorophyll
• What type of cell are chloroplasts found in?

  Green plant cells
• What is the function of the cell membrane?

  Controls entry and exit of substances

  
• What type of organisms are cell membranes found in?

  Plant, animal, fungi and bacteria
• What is the function of the vacuole?

  Stores water, sugar and salts
• What type of organisms are vacuoles found in?

  Plant
• What is the function of the nucleus?


  Controls the activities of the cell and contains genetic material.

  
• What type of organism does not have a true nucleus?

  Bacteria
• How is the genetic material in a bacteria organised?

  A circular chromosome and plasmids
• What is the function of plasmids?

  Code for synthesis of a few proteins not coded for by the bacterial chromosomes. Can be used in genetic engineering.

  
• What type of organisms are plasmids found in?

  Bacterial cells
• Do bacteria contain mitochondria?

  NO
• What is the function of the ribosomes?

  Site of protein synthesis
• What is the function of the of the cytoplasm ?


  The site of chemical reactions
• What is the cell wall of plants made of?

  Cellulose
• What is the cell membrane made of?

  Phospholipids and proteins
• What is passive transport?


  The movement of of substances/molecules down a concentration gradient from a high concentration to a low concentration that does not require energy

  
• What is osmosis?


  Osmosis is the movement of water molecules down a concentration gradient across a selectively permeable membrane from a high concentration to a low concentration. It is a passive process.

  
• Name 2 examples of passive transport

  Diffusion and osmosis
• Name the type of molecules which can move by passive transport through the cell membrane

  glucose, carbon dioxide, water, oxygen
• That term is used to describe the condition of a plant cell which has been place in a concentrated salt solution?

  plasmolysed
• Describe in terms of the movement of water molecules what happen when a plant cell is placed in a concentrated salt solution

  Water molecules move by osmosis from a high water concentration inside the cell to a low water concentration outside the cell and the cell becomes plasmolysed.
• Plasmolysis - draw a plasmolysed cell

  
• The term used to describe a plant cell that has swelled with water because it has been placed in pure water

  turgid
• Turgid - draw a turgid plant cell

  
• Describe in terms of the movement of water molecules what happen when a plant cell is placed in pure water

  Water molecules move by osmosis from a high water concentration outside the cell to a low water concentration inside the cell and the cell becomes turgid.
• osmosis - study the image and put into your own words what is happening.

  
• Explain what would happen if an in animal cell was placed in pure water

  Water molecules move by osmosis from a high water concentration outside the cell to a low water concentration inside the cell and the cell bursts

  
• Describe what would happen to an animal cell if it was placed in a concentrated salt solution.

  Water molecules move by osmosis from a high water concentration inside the cell to a low water concentration outside the cell and the cell shrinks

  
• What is active transport?

  The movement of molecules or ions into or out of a cell from a region of lower concentration to a region of higher concentration via membrane proteins using energy

  
• What supplies the energy needed for active transport?

  ATP
• Describe the structure of DNA

  double helix held together by complementary base pairs

  
• What is the function of DNA?

  DNA carries the genetic information for making proteins.
• Name the four bases in DNA

  Adenine, Thymine, Cytosine and Guanine

  
• What is the DNA base pairing rule?

  G-C, A-T

  C is always paired with G and A is always paired with T.