Chapter 7 Cell Structure and Functions

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Chapter 7Cell Structure and Functions
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Chapter Outline

• 7-1 Life is Cellular
• 7-2 Eukaryotic Cell Structure
• 7-3 Cell Boundaries
• 7-4 The Diversity of Cellular Life

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Microscopes and Scientists

• 1. 1665 Robert Hooke
• used compound microscope to look at cork (dead
  wood)
• called small chambers cells
• 2. Anton Van Leeuwenhoek used single lens
  microscope saw tiny organisms in pond water

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Microscopes and Scientists

• 3. Mathias Schleiden concluded that plants are
  made of cells
• 4. Theodore Schwann concluded that animals are
  made of cells
• 5. Rudolph Virchow stated cells come from
  existing cells

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The Cell Theory

• All living things are composed of cells.
• Cells are the basic units of structure and
  function in living things.
• New cells are produced from existing cells.

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Exploring the Cell

• 1. Electron microscopes
• Samples are put in a vacuum must be dead
• Transmission electron microscopes (TEM) beams of
  electrons are
• passed through a thin sample
• Scanning electron microscope (SEM) beam of
  electrons move over the surface of a sample

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Prokaryotes and Eukaryotes

• 1. All cells have a cell membrane and contain DNA
• 2. nucleus a large structure that contains the
  cells genetic material in the form of DNA
• 3. Prokaryotes cells that do not contain a
  nucleus
• Small and simple cells
• Bacteria are prokaryotes

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Prokaryotes and Eukaryotes
Cell membrane

• 4. Eukaryotes cells that contain a nucleus
• Large and complex cells Highly specialized
• Can be unicellular (one celled organism) or
  multicellular
• Plants, animals, fungi and protists are
  eukaryotes

Prokaryotic Cell
Eukaryotic Cell
Cytoplasm
Nucleus
Organelles
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Cell Organelles

• 1. Eukaryotic cells contain organelles
  specialized structures that perform functions
  within the cells

2. Cytoplasm portion of cell outside the nucleus
3. Nucleus control center of the cell
4. Chromatin DNA bound to protein
5. Chromosomes condensed form of chromatin seen during division
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Cell Organelles
6. Nucleolus dense region in nucleus where ribosomes are made
7. Ribosomes make proteins with instructions from the nucleus
8. Endoplasmic Reticulum site where lipids, proteins and other materials are made two types- smooth and rough
9. Golgi Apparatus modifies, sorts, and packages proteins and materials
10. Lysosomes organelle filled with enzymes that breakdown wastes
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Cell Organelles
11. Vacuoles structure that stores water, salts, proteins, and carbs
12. Mitochondria convert energy from food into compounds the cell can use
13. Cloroplast capture energy from sunlight and covert to chemical energy
14. Cytoskeleton network of proteins that maintains cell shape and helps in cell movement
15. Centrioles organelle that helps in cell division in animal cells
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Do now vocab review

• ________________ basic unit of life
• ________________ DNA bound to protein
• ________________ cells that contain a
• nucleus
• ________________ specialized structures found
  in some cells
• ________________ mass of solute in a given
• volume of solution

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Bonus Question

• What is the term that describes the movement of
  the smell of popcorn?

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Cell Boundaries

• Cell membrane thin flexible barrier that
  regulates what enters and leaves the cell.
• 1. Most cell membranes have a lipid bilayer
• 2. Contain proteins and carbohydrates

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Lipids and water

• http//telstar.ote.cmu.edu/Hughes/tutorial/cellmem
  branes/orient2.swf

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Cell Boundaries
Plant Cell

• Cell Wall provides support and protection
• 1. Present in plants, algae, fungi and many
  prokaryotes
• 2. Cell walls lie outside the cell membrane
• 3. Composed mostly of a carbohydrate called
  cellulose

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Diffusion through boundaries

• 1. concentration mass of solute in a given
  volume of solution
• Ex 12 g salt in 3L water 4g/L
• 2. diffusion is the movement of molecules from an
  area of higher concentration to an area of lower
  concentration
• 3. equilibrium when concentration of solute is
  same throughout area

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Diffusion video
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Diffusion visual

• website

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Osmosis

• 4. Osmosis diffusion of water across a
  selectively permeable membrane
• Water can move across the membrane, and many
  solutes cannot

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Osmosis

• Terms for concentrations on sides of a membrane
• Isotonic concentration is same on both sides
• Hypertonic concentration of solute is higher
• Hypotonic concentration of solute is lower
• Cells are usually near isotonic solutions, so
  that they do not burst

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• 5. Facilitated Diffusion protein gates help
  certain molecules diffuse

Glucose molecules
High Concentration
Cell Membrane
Protein channel
Low Concentration
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• 6. Active transport uses energy to move
  molecules from an area of low concentration to
  high concentration
• Animation
• Normally cells have a lower Na concentration
  than outside. To keep it that way, cells have to
  pump Na out of the cell.

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• Endocytosis process of taking material into
  cells by forming a pocket of cell membrane
• Phagocytosis surrounding food particles
• Pinocytosis surrounding liquids
• Exocytosis process of releasing materials

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Review of Cell transport

• Wiley.com

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Label the organelles
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Unicellular vs. Multicellular

• 1. unicellular organisms one-celled organism
  yeast, volvox aureus
• 2. multicellular organisms
• Cell specialization cells throughout an organism
  can develop in different ways to perform
  different tasks
• Specialized animal cells
• Red blood cells carry oxygen throughout body
• Pancreatic cells many ribosomes to make
  proteins and enzymes for digestion
• Muscle cells overdeveloped cytoskeleton

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Multicellular organisms

• Levels of organization (Individual organism)
• Cells?tissues?organs?organ systems

Muscle cell
Smooth muscle tissue
Stomach
Digestive system