Organelles

• Describe mitochondria:

  • Site of cellular respiration
  • Powerhouse of cells
  • Double membrane structures
  • Spread throughout cytoplasm
  • Cellular reactions that release energy
• Describe the role of nuclear pores?

  • Nuclear pores allow large molecules to enter or exit the nucleus
• State the difference between the rough ER and the smooth ER:

  • Rough ER has ribosomes attached on the surface of the membrane, while smooth ER doesn't.
• Describe the endoplasmic reticulum (ER)

  • Forms channels and are involved in storing and transporting molecules
• Describe the Golgi Apparatus/Body:

  • Modifies and packages proteins
  • Series of flattened membranous bags stacked upon the other
• Describe the ribosomes:

  • Site of protein synthesis
  • Spherical, small organelles
  • Either in cytoplasm or attached within the cells such as the endoplasmic reticulum (ER)
• Describe the nucleous:

  • Within the nucleus
  • Composed of RNA which has a role in protein synthesis
• Describe the phospholipid bilayer in the cell membrane:

  • 2 layers
  • Phospholipids have hydrophilic head which is water loving and hydrophobic tails which is water hating
• Describe cytosol:

  • Liquid part of cytoplasm
  • Made up of mixture of substances dissolved in water
• Describe lysosomes:

  • Contain digestive enzymes
  • Small spheres, formed from Golgi Apparatus
• Describe the cell membrane:

  • Surrounds the cell
  • Separates the cell contents from the external environment
  • Controls what enters and leaves the cell
• What does protoplasm refer too?

  • Refers to nucleus and cytoplasm together
• Explain difference between cilia and flagella and what they have in common:

  • Cilia are short and numerous projections off the cell membrane, to move substances over the surface of the cell
  • Flagella are long and fewer (one or two) and are used to propel or move the cell
  • Both are important in moving particles or cells
• Describe the terms fluid and mosaic in the fluid mosaic model:

  • The structure in the membrane are constantly moving = fluid
  • It is composed of many different types of molecules = mosaic
• What does a cell include?

  • Cell membrane
  • Cytoplasm
  • Organelles
  • Inclusions
  • Cytoskeleton
• Describe the nucleus:

  • Controls all activity in cell
  • Contains genetic material (DNA and RNA)
• What does DNA do when cell isn't dividing:

  DNA in form of long strands called chromatin
• What does DNA do when cell is dividing:

  Chromatin thickens coil to form chromosomes
• What do all cells have and what do plant and animals cells have in common?

  • Cell membrane
  • Cytoplasm
  • Genetic material
  • In common: Mitochondria
• Main functions of cell membrane:

  • Physical barrier
  • Regulate the passage of materials (homeostasis)
  • Sensitivity (hormone sensitivity)
  • Support (cytoskeleton)
  • Indentification
• State cell theory:

  The cell theory states that all organisms are made up of cells, which are the basic unit of life and arise from pre-existing cells.
• Describe vesicles:

  Membrane bound sacs
• Describe Eukaryotic cells:

  Plant and animal cells with a nucleus and membrane-enclosed organelles
• Describe the cytoplasm:

  • Thick fluid between the cell membrane and the nucleus
  • Consists of organelles suspended in cytosol
• Describe microtubes:

  • Part of cytoskeleton
  • Hollow rods that keep organelles in place or move them around the cell
• Proteins in cell membrane:

  • Carrier
  • Channel
  • Cell identity markers (glycoprotein)
  • Receptor protein
• Explain why cells vary in size and shape?

  • To provide different structures of tissues and organs needed to carry out the functions necessary for life
• Describe Prokaryotic cells:

  • Unicellular organisms without a nucleus or membrane-enclosed organisms