Cell Structure

• All living organisms are made up of cells.
• Cells need to be viewed through a microscope.
• Plants and Animal cells

  
• Bacteria cell

  They dont contain any organelles

  
• Nucleus 


  Contains genetic information (DNA) in animal, plant and fungal cells
• Plasmid 


  A small ring of DNA only found in bacterial cells
• Cell membrane

  Controls entry and exit of substances such as oxygen and carbon dioxide.
• Cytoplasm

  Liquid inside cells containing organelles, the site of various chemical reactions
• Cell Wall

  The outer layer of plant, fungal and bacterial cells which helps support the cell
• Vacuole 


  Membrane bound sac that stores a solution of water found in plant and fungal cells
• Mitochondria


  Main site of energy (ATP) production in aerobic respiration in animal plant and fungal cells
• Ribosome 


  Site of protein synthesis in cells
• Cell walls of plant, fungal and bacterial cells are not all the same. They are made of different chemicals.
• Chloroplast 


  The site of photosynthesis in plant cells
• Give one difference between the structure of the bacterial cell and an animal cell.

  Animal cells contain a nucleus
• Why can't antibiotics be used to treat diseases caused by viruses?

  viruses live inside cells
• Name one structure that is found in a plant cell but is not found in a bacterial or an animal cell.


  Chloroplast
• What type of microscope is needed to see ribosomes and mitochondria?

  Electron
• Describe how the long tail and the mitochondria help the sperm to do its job.

  Long tail- moves the sperm towards the egg

  Mitochondria- to transfer energy by use of respiration
• What is the advantage of using an electron microscope?

  Higher magnification
• Cheek cells are a type of body cell.

  Body cells grow through cell division.

  What is the name of this type of cell division?

  Mitosis
• Oxygen will diffuse into the cell.

  Why?

  As oxygen is moving from a high concentration to a low concentration down a concentration gradient
• What does heating a loop in a flame do?

  Kills bacteria
• What does only lifting the petri dish a little do?

  Allow fewer bacteria to enter
• What does placing a loop from a bench to cool do?

  Increase risk of contamination with bacteria
• What is the function of the nucleus?


  To control the activities of the cell
• What does placing a petri dish in an incubator at 25* do?

  Decrease risk of pathogens growing
• What is the scientific name of the Mouth, stomach, intestines, liver and pancreas?

  An organ system
• What is the scientific name of the Layer of cells lining the stomach?

  A tissue
• Why do human skin cells need to divide?

  For growth and repair
• Name one food molecule absorbed into epithelial cells by active transport.

  Sugar
• Where may Human stem cells come from?

  embryos
• What can Human stem cells be used to treat?


  paralysis
• Suggest how the highly folded cell surface helps the epithelial cell to absorb soluble food.

  Increased surface area
• Suggest why epithelial cells have many mitochondria.

  For energy from respiration
• Why is it necessary to absorb some food molecules by active transport?

  helps sugar to be transferred from a low concentration in the gut to a higher concentration in the blood
• Describe the function of muscle cells in the wall of the stomach

  Contract to move food
• What is the function of a ribosome?

  to make protein
• Give one substance that plants absorb by active transport.

  Minerals
• Suggest why the ribosomes cannot be seen through a light microscope.

  too small