Natures Building Blocks

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Natures Building Blocks

• Cells

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• First discovered in 1665 by Robert Hook
• Using a microscope, he looked at cork
• Why did he call them cells?

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All living organisms are composed of cells

• Single celled organisms
• Examples are amoebas, paramecia, protozoa, and
  bacteria
• Bacteria are important!
• Help digestion
• Fix nitrogen
• Cause fermentation
• Cause disease

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• Multicelled organisms
• Examples People plants, etc.
• Cells can come in many different shapes and sizes
• Largest ostrich egg
• Smallest need high powered microscope to see
• (look at shapes on overhead)

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Cell structure and Function

• Plant and animals cells two main
• Cell wall plant cells only
• Made of cellulose in branches and stems
• Made of pectin in fruits
• Holds cells together
• Gives plant structure

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• Cell membrane
• Aka plasma membrane
• Selectively permeable
• Operates through diffusion
• Diffusion transfer of materials from high
  concentration to low concentration
• Osmosis Diffusion of WATER

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• Homeostasis balance that cells strive to
  maintain (steak and dog example)
• Turgidity when a cell has the right amount of
  liquid (turgor turgor pressure)
• Ex plastic bag

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More cell parts.
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Nucleus

• Prokaryotic cells do not have one
• Eukaryotic cells have one (sometimes many)
• Made of nucleic acids, enzymes, and proteins
• Control center of the cell
• Contains the genetic code (DNA)

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Cytoplasm

• Thick clear fluid that surrounds the nucleus
• Suspends other parts of the cell
• Moves materials around to help keep the cell
  alive and functioning

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Organelles

• The mini organs inside cells
• They carry out cell functions

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Mitochondria

• Shaped like a peanut
• Break down nutrients from food and supply cell
  with energy
• Cells that need less energy have a lower number
  of these
• Known as the powerhouse of the cell

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Vacuoles

• Vacuoles are specialized for different functions
• Made of a membrane that holds H2O and other
  materials
• All involve storage
• Some store wastes from the cell
• Some store nutrients and enzymes

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Microtubules

• Are like bones
• Thin, hollow tubes of protein that help give the
  cell structure
• Aid in cell division

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Microfilaments

• Fiber like structures
• Wave back and forth to make a cell move
• Extra credit by tomorrow
• Do both plant and animal cells have these?

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Ribosomes

• Where protein molecules are assembled
• Proteins are a key component of enzymes

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Golgi Apparatus

• Looks like flat sacs bundled together
• Takes water out of protein and prepares it to
  leave the cell

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Endoplasmic Reticulum

• Webbed network of double membranes
• Transports materials within the cell

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Lysosomes

• Digest proteins, carbohydrates, and other
  molecules
• Digests foreign invaders like bacteria
• If other organelles quit working digests them
  too!

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Plastids

• Plant cells only
• 3 types
• Chloroplasts convert suns energy to
  carbohydrates, contain chlorophyll
• Leucoplasts store starch, proteins, and lipids,
  mostly found in seeds
• Chromoplasts creates pigments that give fruit
  its color

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Centrioles

• Centers that organize the microtubules within a
  cell