Cell Parts and Functions

• Cell Theory 

  • All living things are made up of cells.
  • Cells are the smallest working units of all living things.
  • All cells come from preexisting cells through cell division.
• Definition of Cell

  • A cell is the smallest unit that is capable of performing life functions.
• Examples of Cells

  • Amoeba Proteus
  • Plant Stem
  • Bacteria
  • Red Blood Cell
  • Nerve Cell
• Two types of Cells

  • Prokaryotic
  • Eukaryotic
• Prokaryotic

  • Do not have structures surrounded by membranes
  • Few internal structures
  • One-celled organisms,Bacteria
• Eukaryotic

  • Contain organelles surrounded by membranes
  • Most living organisms
• Cell Shape

  • Plants : Has a regular shape
  • Animal : has irregular or round shape
• cell membrane

  • outer membrane of cell that controls movements in and out of the cell
  • double layer 
  • The lipid forms from amphilathic phospolipids, stabilized by cholesterol and contains many embedded ( integral) proteins and many peripheral proteins on its cytoplamic surface
  • Endocytosis is cellular uptake of macromolecules of fluid by plasma membrane engulfment or invagination, followed by the “ pinching off “ or a filles membranous vesicle in the cytoplasma
• major types of endocytosis include

  • phagocytosis
  • pinocytosis
  • receptor-mediated endocytosis
  • exocytosis: cytoplasmic membrane vesicles fuse with the plasma membrane and release their contents go the extracullar place
• Cell wall

  • most commonly found in plant cells & bacteria
  • Supports & Protects cells
• Nucleus

  • direct cells activities 
  • separated from cytoplasm by nuclear membrane / nuclear envelop 
  • contains generic material - DNA
• Nuclear membrane 

  • surrounds nucleus
  • made of two layers
  • opening allow material to enter and leave nucleus
• Chromosomes

  • in nucleus
  • made of DNA
  • contain instructions for traits & characteristics
• Nucleolus

  • inside nucleus
  • contains RNA to build proteins
• cytoplasms

  • gel-like mixture
  • surrounded by cell membrane 
  • contains heredity material
• Endoplasmic Reticulum

  • moves materials around in cell
  • smooth type : lacks ribosomes
  • rough type ( pictured ) : ribosomes embedded in surface
• ribosomes

  • make proteins
  • found on ribosomes and floating throughout the cell
• Mitochondria

  • produces energy through chemical reactions - breaking down fats & carbohydrates
  • controls level of water and other materials in cell
  • recycles and decomposes proteins, fats, and carbohydrates
• Golgi bodies

  • protein ‘ packaging plant ‘
  • move materials within the cell
  • move materials out of the cell
• Lysosomes

  • digestive plant for proteins, fats and carbohydrates 
  • transport undigested material to cell membrane for removal
  • cell breaks down if lysosomes explodes 
  • usually not found in plants