Nelson Ch. 1 Cell Biology

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Nelson Ch. 1Cell Biology

• 1.1 The Cell Theory
• The human body is made up of how many cells?

100 trillion !! Wow!
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Contributors to the Cell Theory

• 1665 Robert Hooke and his primitive
  microscope

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Hookes drawing of cork cells

• Hooke didnt realize that cork cells are actually
  dead and therefore are empty inside.
• 1674 Anton van Leeuenhoek first described
  living cells blood, bacteria unicellular
  pond organisms.

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Anton van leeuenhoek

• Van Leeuenhoek is one of the contributors to the
  invention of the microscope.
• 1820- Robert Brown first described and named the
  nucleus.
• 1838 Theodor Schwann, Mathias Schleiden stated
  that both animal and plants are made of cells
• 1858 Rudolph Virchow theorized that all cells
  come from preexisting cells.

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The cell theory states

• All living things are composed of one or more
  cells.
• The cell is the smallest entity that retains the
  property of life.
• New cells arise only from cells that already
  exist.

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Classification of cells
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How many organelles can you recall?

• In partners, brainstorm all the organelles you
  can think of and what they do

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Cell structure

• The cytoplasm is a fluid that contains all the
  parts of a cell inside the cell membrane
  outside the nucleus. Chemical activities happen
  here, nutrients are transported processed,
  wastes are stored.

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Cell Membrane

• Outermost boundary of the cell
• Made of proteins and a bilayer(double) of lipid
  (fat)molecules
• Holds the cell content in place
• Regulates the movement of materials into and out
  of the cell

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Nucleus

• Control center of the cell
• Contains threadlike chromosomes made of genes
• Chromosomes are made of DNA
  (deoxyribonucleic acid)
• Pores in the envelope allow some things to pass
  through

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Nucleolus

• Specialized region at the centre of the Nucleus -
  can contain one nucleous or more(nucleoli)
• Produce ribosomes (protein factories)
• Involved in making ribonucleic acid (RNA)

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Cytoplasmic organelles mitochondria

• Oval shaped with 2 membranes a smooth outer
  and inner folded membrane called cristae
• power house or powerplant of the cell
• Site of cellular respiration energy is released
  from sugar energy is stored in ATP
• Mitochondria contain their own DNA ?

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ribosomes

• Site of protein synthesis
• Nick name protein factory
• Amino acids are joined together to make proteins
  here
• Made of rRNA and proteins, the smallest
  organelles (20nm)
• There are many ribosomes in one cell attached to
  the endoplamsic reticulum

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Enodplasmic reticulum ( ER)

• A network of interconnected canals that transport
  materials throughout the cytoplasm
• Rough ER has ribosomes
• Smooth ER no ribosomes- makes fats (lipids)

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Golgi apparatus

• Stores, modifies packages proteins from the RER
• Looks like a stack of flattened pancakes
• Pinches off to form small protein filled vesicles
• Forms Lysosomes

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lysosomes

• Organelles bound by a single membrane
• Formed by the Golgi apparatus
• Contain enzymes to break down large molecules
  cell parts
• Only found in animal cells
• Nick named Suicide sac

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Microfilaments microtubules

• Microfilaments are tubelike structures in the
  cytoplasm that help provide shape movement
• Microtubules are tubelike fibres (made of
  protein) that transport materials through the
  cytoplasm also found in flagella cilia

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Flagella and cilia

• A flagellum is a whip like tail
• that aids in movement
• Flagella spin like a propeller
• Cilia (cilium)are shorter, hair like
• structures that aid in movement.

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VACUOLES

• Fluid filled sacs
• Storage for sugars, minerals, proteins water
• Gives plant cells physical support
• Plant cells have large, central vacuoles
• Animal cells have many smaller vacuoles

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PLASTIDS

• Chemical factories or storehouses for food or
  pigments
• Chloroplasts contain chlorophyll are the site
  of photosynthesis
• Chromoplasts store pigments (orange, yellow)
• Amyloplasts colorless and store starch (potato)

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Centrioles

• Small protein bodies that are found in the
  cytoplasm of animal cells
• Play an organizational role in cell division

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Plant cell wall

• Protects supports the cell
• Primary cell wall made of cellulose
• Some plant cells have an additional secondary
  wall with a middle lamella in between that
  contains a sticky pectin to hold cells together

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Plant cell and organelles
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Animal cell and organelles
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Differences between plant and animal cells

• PLANT
• Have a cell wall
• Have a large central vacuole
• Contain plastids
• Have a definite shape
• Do not contain lysosomes
• Do not contain centrioles

• ANIMAL
• Have only a cell membrane
• Have many smaller vacuoles
• Dont contain plastids
• Have a more irregular shape
• Contain lysosomes
• Contain centrioles

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Plant Animal
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WATCH THE CELL ANIMATION AGAin and see if you can
recognize some of the structures

• Onion cells stained - can you see the nucleus?