Cells

• Cells are the basic unit of life and are the building blocks of all living things
• Cells take in nutrients from food and convert them into energy
• Cells give structure to the body
• Cells carry out specialized functions
• The oldest type of cells is know as the prokaryotic cells whilst the larger and more complex cells are known as eukaryotic cells
• Prokaryotic cells are unicellular (have one cell) and are small compared to eukaryotic cells
• Prokaryotic cells have no true nucleus or membrane bound organelles
• Eukaryotic cells have a true nucleus containing DNA and are large cells
• Prokaryotic cells divide via binary fission
• Prokaryotic cells have a cell wall made up of polypeptides and amino acids
•   Eukaryotic cells can either be identified as an animal cell or a plant cell
• Eukaryotic cells have membrane bound organelles such as the mitochondria
• Eukaryotic cells divide by mitosis and meiosis
• A cell wall is only present in prokaryotic cells and plant eukaryotic cells
• Organelles are tiny organs present inside the cell which are responsible for carrying out specific jobs.
• Animal cells have an irregular shape since they have no cell wall.
• A cell membrane is a thin layer made up of proteins and lipids that surrounds the cell and controls what goes in and out
• The cell membrane protects the cell
• The cell membrane is semi permeable, meaning it only allows small molecules to enter or leave the cell
• The nucleus controls everything in the cell. It holds the genetic material
• The nucleus controls cell division and production of enzymes
• The cytoplasm is a jelly like substance which mainly provides structure to the cell and provided a medium in which chemical reactions can take place.
• Cytoplasm is made up of mostly water since water needs a lot of energy to heat it and is a very good solvent.
• The mitochondria are sausage shaped organelles which carry out respiration. This organelle has an outer and inner membrane.
• Ribosomes are responsible for the synthesis of proteins in the cell. These are not membrane bound organelles.
• Temporary vacuoles control the water content in the cell. This process is also known as osmoregulation
• Food particles in cells are made up of glycogen.
• Plant cells are eukaryotic cells. They have all of the typical membrane bound organelles however they also have a cell wall, a large permanent vacuoule and chloroplasts.
• The cell wall provides structure and support. It is made up of cellulose, a polysaccharide, and is often found as a custodial shape.
• A cell wall is fully permeable
• A permanent vacuole is filled with a liquid known as cell sap and is found in the middle of the cell.
• Cell sap is a solution of sugar and salts which the plant needs
• The permanent vacuole requires water for support and turgor pressure.
• Chloroplast are organelles needed for photosynthesis. They contain chlorophyll, a green pigment which gives the plant a green colour.
• The chlorophyll uses light energy from the sun and uses it to build food.
• Cell division is the cell - number increase by dividing
• Cell division occurs in different layers of the skin and root tips and buds
• When cells divide, they produce to daughter cells.
• One of the two daughter cells becomes specialized whilst the other one continued to divide into more cells
• Animal cell division

  1. DNA is replicated
  2. Nucleus divides
  3. Cytoplasm divides through splitting of cleavage