Cells are the basics of life 2.1 and 2.2

• Cell Theory

  • Cells are the smallest structural and functional units of life.
  • Cells originate from existing cells through cell division.
  • Cells contain hereditary material.
• Fluid Mosiac Model - membrane


  Separates the cell cytoplasm from its surroundings and controls the exchange of materials between the cell and its environment
• Fluid Mosaic Model - Phospholipids


  • Arrange themselves into a two-layer sheet called a phospholipid bilayer
  • Hydrophilic ("water-loving") heads are arranged to face outward, exposed to the aqueous solutions on both sides of a membrane
  • Hydrophobic ("water-fearing") tails are arranged inward, mingling with each other and shielded from water
• Fluid Mosaic Model - Membrane


  • Suspended in the phospholipid bilayer are proteins that help regulate traffic across the membrane
• Different locations of ribosomes and where they synthesise proteins

  • Ribosomes can be found floating freely in the cytoplasm or attached to the endoplasmic reticulum (ER).
  • Free ribosomes typically synthesize proteins that function within the cytoplasm.
  • Ribosomes attached to the rough ER synthesize proteins that are either incorporated into cell membranes, exported from the cell, or sent to lysosomes​
• Nucleus Structure


  Enclosed in a double-layered

  nuclear membrane

  Nucleolus inside

  contains RNA

  Nuclear pores

  allow a type of

  RNA (messenger

  RNA) to leave the

  nucleus following

  transcription
• Nucleus Function


  Controls the cell activities. Contains

  DNA, which codes for proteins. This DNA is passed onto daughter cells in mitosis and meiosis.
• Nucleus Organelle Definition


  Contains the cell's hereditary material and controls cellular activities.
• Mitochondria Organelle Definiton


  An organelles where respiration occurs, releasing energy ATP
• Mitochondria Function

  Site of stages 2 and

  3 of aerobic cellular

  respiration, which releases usable

  energy in the form

  of ATP molecules
• Mitochondria Structure


  Has a double

  membrane, with the inner membrane

  folded to form

  cristae, with matrix between
• Chloroplast Organelle Definition 


  Chloroplast (plants)

  an organelle where photosynthesis occurs; contains chlorophyll
• Chloroplast Structure 


  Double membrane comprising grana

  (stacks of membrane discs called thylakoids) and stroma (fluid). Grana contain chlorophyll.
• Chloroplast Function 


  Site of photosynthesis, which converts carbon dioxide and water, with the assistance of light, to glucose and oxygen

  Animal cells do not have chloroplasts.
• Golgi Apparatus Organelle Defintion


  Golgi apparatus

  an organelle consisting of layers that modifies and packages proteins
• Golgi Apparatus Structure


  Layers of membrane- bound stacks
• Golgi Apparatus Functionn


  Modifies and

  packages proteins into secretory vesicles for

  exporting from the cell
• Vesicles Organelle Defintion 


  an organelle that transports materials between organelles and within the cell
• Vesicles Function 


  Transport of materials (e.g.

  sac
• Vesicle Structure


  Membrane-bound
• Endoplasmic Reticulum (Smooth and Rough) Organelle Defintion


  Smooth endoplasmic reticulum

  an organelle that synthesises and transports lipids

  Rough endoplasmic reticulum

  an organelle that transports proteins in vesicles to the Golgi apparatus
• Different Locations of Ribosomes and Where They Synthesize Proteins

  • Ribosomes can be found floating freely in the cytoplasm or attached to the endoplasmic reticulum (ER).
  • Free ribosomes typically synthesize proteins that function within the cytoplasm.
  • Ribosomes attached to the rough ER synthesize proteins that are either incorporated into cell membranes, exported from the cell, or sent to lysosom
• Lysosome Organelle Defintion 


  Involved in the breakdown of waste materials and cellular debris.
• Lysosomes Structure


  Lysosomes have a single membrane and are filled with digestive enzymes.
• Lysosomes Function


  Lysosomes are involved in "intracellular digestion". They are important because lysosomes help break down old cell parts, digest materials in the cell, and objects that enter the cell.
• Cytoskeleton Structure and Function


  The cytoskeleton is a structure that helps cells maintain their shape and internal organization, and it also provides mechanical support that enables cells to carry out essential functions like division and movement.
• Prokaryotes 


  Prokaryotic Cells - Prokaryotic cells range from 0.1 to 5.0 micrometers

  Found in bacteria and archaea

  Smaller, simpler

  Most have cell walls; some have capsules, fimbriae, and/or flagella.

  Have a plasma membrane

  No membrane-bound organelles

  Have a nucleoid region containing a single circular chromosome

  Have ribosomes
• Eukaryotes

  Found in protists, plants, fungi, and animals

  Larger, more complex

  Plant cells have cell walls; animal cells are surrounded by an extracellular matrix.

  Have a plasma membrane

  Membrane-bound organelles (for example, nucleus, ER)

  Have a nucleus containing

  one or more linear chromosomes

  Have ribosomes