CELLS

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CELLS!!!!!
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Prokaryotic vs. Eukaryotic cells

• A prokaryotic cell is one that does not contain a
  nucleus or any organelles. Bacteria are
  prokaryotic cells. They contain DNA that is not
  enclose in a nucleus and some ribosomes in the
  cytoplasm. They are primitive cells
• Eukaryotic cells contain a nucleus and other
  membrane-bound organelles like mitochondria and
  vacuoles. They are found in all organisms other
  than bacteria.

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Scientists who studied cells

• Anton van Leeuwenhoek (1600)
• developed the first microscope
• Robert Hooke (1660)
• named the parts of a cork cell
• Robert Brown (1830)
• named the dark part in the center the nucleus
• Mathias Schleiden (1833)
• concluded that plants are made of cells
• Theodore Schwann (1833)
• concluded that animals are made of cells
• Rudolph Virchow (1855)
• cells arise form preexisting cells

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Cell Theory

• The work of many scientists has given rise to our
  modern cell theory
• All living things are composed of cells.
• Cells are the basic unit of structure and
  function in living things.
• All cells come from preexisting cells.

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Prokaryotic Cell
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Bacteria
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Animal Cells

• There are a few important differences between
  plant and animal cells.
• Animal cells have
• smaller vacuoles
• no cell walls
• centrioles
• no chloroplasts
• lysosomes

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Animal Cell
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Animal Cell
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Plant cells

• Plant cells have
• large vacuoles for storage of water (support)
• cell walls (support)
• no centrioles
• plastids-chloroplasts, leucoplasts, chromoplasts
  (storage of pigments)
• no lysosomes

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Plant Cell
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Plant Cell
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Structure and function

• A cells structure is directly related to its
  function!
• Long and skinny cells are good for movement.
  (muscle and nerve cells)
• Round cells are good for transportation. (red
  blood cells)
• Flat cells are good for covering and protection.
  (skin)
• Columnar cells are good for absorption.
  (intestines and stomach)

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Organelles

• An organelle is a small structure inside a cell
  that performs a specific function.
• cell wall -vacuole
• cell membrane -plastid
• nucleus -cytoskeleton
• cytoplasm -cilia
• mitochondria -flagella
• ribosome -centrioles
• endoplasmic reticulum -nucleolus
• golgi apparatus
• lysosome

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Cell Membrane

• The cell membrane is composed of
• phospholipids (two fatty acids)
• hydrophilic heads point to inside and outside of
  cell
• hydrophobic tails in the middle
• proteins
• used to carry molecules in and out of the cell
• carbohydrates
• used for recognition of self (antigens)
• Its function is to regulate the substances that
  come into and out of the cell.

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Cell Membrane
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Cell or Plasma Membrane
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Cell Wall
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Nucleus

• The function of the nucleus is to hold the DNA
  which stores the genetic code for the cell.
• There is a part of the nucleus that functions to
  make ribosomes that is called the nucleolus.

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Nucleus
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Nucleus
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Cytoskeleton

• The cell has an internal support network composed
  of microtubules and microfilaments that together
  are called the cytoskeleton.
• The cytoskeleton runs throughout the cytoplasm
  and holds the organelles in place.
• Specialized microfilaments and microtubules
  become flagella and cilia that are used for
  movement.

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Cytoskeleton
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Plastids

• Plastids are found only in plants and are
  organelles that store pigments. The most famous
  is the chloroplast that stores the green pigment
  cholrophyll.
• Leucoplast (white pigment)
• Chromoplast (red pigment)

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Chloroplast
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Mitochondria

• The mitochondria is considered the power house
  of the cell. It is the site where chemical energy
  in food is converted into the cellular form of
  energy called ATP.
• It is composed of an internal membrane called the
  cristae. The inside of the cristae is called the
  matrix.

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Mitochondria
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Mitochondrion
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Mitochondrial Evolution
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Ribosomes

• Ribosomes are the organelle where proteins are
  made. They float freely in the cytoplasm and are
  attached to the endoplasmic reticulcum to form
  rough ER.
• Ribosomes are the only organelle that is found in
  the cytoplasm of bacteria cells.

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Endoplasmic Reticulum

• The ER is specialized to help transport things
  throughout the cell.
• It is ROUGH when there are ribosomes attached to
  it. It is SMOOTH when there are no ribososmes
  attached.

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Endoplasmic Reticulum
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Lysosome

• Lysosomes are the areas of the cell responsible
  for digestion and waste removal.

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Lysosomes
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Golgi Apparatus

• The golgi body is the area of the cell that is
  responsible for collecting, modifying, packaging
  and distributing molecules. Proteins that are
  made at the ribosome will travel to the GA to be
  prepared and sent to the appropriate part of the
  cell or exported out of the cell.

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Golgi Apparatus
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Vacuole

• Vacuoles are the storage areas of the cell. The
  vacuoles store thing like salt, water, proteins
  and carbohydrates.
• In plant cells, there is a large central vacuole
  that stores water. When plants go into water
  stress, they lose the water in the central
  vacuole which results in wilting.