SCIENCE Chapter 1 Lesson 1

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SCIENCEChapter 1 Lesson 1
Above is bacteria on the head of a pin.

• How Do Plant and Animal Cells Differ?

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The microscope

• Invented by Robert Hooke in 1665.
• Hooke was one of Englands greatest scientist.
• First thing observed was a slice of cork.
• The cork looked like little rooms in a
  monasterythese were called cellsRobert called
  these views, therefore, he called them cells.
• Anton van Leeuwenhoek, a Dutch cloth merchant
  from Delft, Holland was a contemporary of Hooke.
  (Find out what he did!)

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Cells

• Cells have three basic componentsa plasma
  membrane, a central nuclear region, and
  cytoplasm.
• Plasma membrane is the surface of the cell that
  protects the cell and allows for food and waste
  exchanges.
• Nuclear region is the area that controls all the
  cells function and stores the DNA. (Some cells
  are missing this area, but dont reproduce.)
• Cytoplasm is the gel-like substance filling the
  cell between the plasma membrane and the nuclear
  region.

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Cell Theory

• Cell Theory is only about 150 years old.
• 1) All living things are made up of one or more
  cells.
• 2) Cells are the basic living units of all
  living things.
• 3) All cells come from preexisting cells. (Every
  living thing begins as one cell than the cells
  divide and the thing grows!)

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Parts of a Cell

• Cell membrane The thin layer that covers the
  cell.
• Cell wall (Only found in plant cells!) A stiff
  outer layer that protects plant cells and gives
  it shape.
• Cytoplasm the gel-like substance in the cell
  that holds the organelles.
• Organelles Tiny structures that carry out cell
  activities.

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Parts of a Cell continued.

• Mitochondria a bean shaped organelle that
  releases energy that is stored in sugars to carry
  out the cells activities. (Muscle cells have
  more mitochondria, because they require more
  energy.)
• Chloroplast (Only found in plant cells!) This
  enables plants to make its own food.
• Vacuole A space in the cell membrane that
  stores food to enter the cell and waste to exit
  the cell. (The cells garage!)

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Parts of a Cell continued.

• Nucleus the center of most cells that directs
  all the cells activities. (The cells brain!)
• Chromosome This is a structure that contains
  the information necessary to determine the
  characteristics of the organism. (Humans have 23
  pairs of chromosomes in their body cells.)
• Nuclear Membrane This surrounds the nucleus and
  holds it together.

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DNA
DNA A molecular model 1 hydrogen, 2 oxygen, 3
carbon in the helical phosphate ester chains, 4
carbon and nitrogen in the cross-linked purine
and pyrimidine bases, 5 phosphorus B double
helix
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DNA

• DNA stands for deoxyribonucleic acid.
• Chromosomes are made of DNA and other proteins.
• DNA is called the blueprint of life.
• DNA contains all the information and instructions
  about how the cell is built.