Cells

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Cells

• Cell Theory
• Prokaryotes vs. Eukaryotes
• Cellular Organization

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Important Scientists

• Robert Hooke
• 1655 First person to look at dead cork cells
• First to use the term cell
• Anton van Leeuwenhook
• 1673 First person to observe living cells

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Cell Theory

• All living things are composed of one or more
  cells.
• Cells are the basic units of structure and
  function in an organism.
• Cells come only from the reproduction of existing
  cells.

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Eukaryotes

• Usually in multicellular organisms
• Cells containing a membrane bound nucleus and
  other membrane-bound organelles.

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Prokaryotes

• Unicellular organisms (Example bacteria)
• Cells lacking membrane-bound nucleus and
  organelles.

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Cell Size

• Limited by the ratio of volume to surface area.

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Cell Shape

• Determined by function of cell.

Elodea Cells
Nerve Cell
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Cell Membrane

• Selectively permeable
• Made of lipids and proteins
• Phospholipids
• Form a lipid bilayer
• Peripheral Proteins
• On the outside and inside of lipid bilayer
• Integral Proteins
• In between lipid bilayer

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Cell Membrane
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Cytoplasm

• Made of fluid called cytosol, an aqueous
  solution.
• Contains the various organelles of the cell.

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Mitochondria

• Power house of cell
• Creates ATP (what cells use for energy)
• Folds inside are called cristae
• Contain their own DNA
• Grow and divide by themselves

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Mitochondria
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Ribosomes

• Most numerous organelle
• No membrane
• Synthesize protein
• Float free in cytosol or are attached to rough
  endoplasmic reticulum

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Ribosomes
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Endoplasmic Reticulum

• Highway of the cell
• Made of tubules and sacs
• Rough ER covered in ribosomes
• Exports large amounts of protein from the cell
• Smooth ER no ribosomes
• Specialized job according to cell type

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Endoplasmic Reticulum
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Golgi Apparatus

• The UPS of the cell
• Modifies the proteins to be exported outside the
  cell

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Golgi Apparatus
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Lysosomes

• Filled with hydrolytic enzymes
• Digests old organelles
• Rare in plant cells

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Lysosomes
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Cytoskeleton

• Long protein strands
• Provide structure and support
• Move organelles around during mitosis
• Microfilaments Actin strands
• Microtubules Spindle fibers (move chromosomes
  during mitosis)

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Cytoskeleton
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Cilia Flagella

• Cilia rows of tiny hairs on outside of
  membrane
• Flagella tail on outside of membrane
• Both are used to move cell around

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Cilia Flagella
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Nucleus

• Nuclear Envelope surrounds nucleus
• Nuclear Pores Allow RNA to pass in and out of
  nucleus
• Inside Nuclear Envelope
• Chromatin (DNA)
• Nucleolus (Synthesizes ribosomes)

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Nucleus
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Plant Cells
Have rigid cell walls.
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Plant Cells

• Vacuoles store enzymes, food, and wastes

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Plant Cells

• Plastids
• Similar to mitochondria
• 2 membranes
• Contain DNA
• Provide color to plants/flowers

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Plant Cells - Plastids
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Cellular Organization

• Cells are organized into...

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Cellular Organization

• Tissues which are organized into...
• groups of cells that carry out a specific function

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Cellular Organization

• Organs which are organized into...
• several types of tissues that interact to perform
  a specific function

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Cellular Organization

• Organ Systems which are organized into
• a group of organs that work together to perform a
  specific task

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Cellular Organization

• An ORGANISM!
• Which usually are organized into populations,
  which fit into their communities, which fit into
  their ecosystems!

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Colonial Organization

• Colonies of genetically identical cells
• Volvox (Alga)
• Hollow spheres that contain hundreds of cells