CELLS and CELL PROCESSES

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CELLS and CELL PROCESSES

• Test Review Notes

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CELLS

• All living things are composed of cells, from
  just one to many millions, whose details are
  usually visible only through a microscope.
• Different body tissues and organs are made up of
  different kinds of cells.
• What are the four types of body tissues?
• Name at least five different organs.

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• The cells in similar tissues and organs of other
  animals are like those in humans, but differ from
  cells found in plants.
• How are plant cells different from animal cells?

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• Within cells, many of the basic functions of
  organisms such as extracting energy from food
  and removing wastes are carried out.
• The way in which cells function is similar in all
  living organisms.
• How do cells get their food?
• How do cells get rid of their wastes?

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• About two-thirds (66) of the weight of cells is
  accounted for by water. This water gives cells
  many of their properties.
• Why is the water found in a cells cytoplasm so
  important for the cells survival?

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Food and Nutrition

• Food provides molecules that serve as fuel and
  building materials for all organisms and their
  cells.
• Plant cells take in carbon dioxide and water and
  use the energy from sunlight to chemically change
  them to food (sugar) and oxygen.
• What is this process called?
• PHOTOSYNTHESIS.

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• This food can be used immediately for fuel or
  stored for later use.

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• Organisms that eat plants break down the plant
  structures to produce the materials and energy
  they need to survive.
• Then they are consumed by other organisms.

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• All organisms (even plants) release the energy
  stored in sugar through a chemical change that
  requires oxygen and produces carbon dioxide and
  water, in addition to energy.
• What is this process called?
• RESPIRATION

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• Some of the energy from respiration is released
  as heat.
• What example can you think of for the above
  statement?
• Almost all food energy comes originally from the
  sun.
• How does a second level consumer get its energy
  from the sun?

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MATTER and CELLS

• Matter is made up of tiny particles called atoms,
  which are far too small to see even with a
  microscope.
• Atoms are the smallest units of an element.
• Elements are substances that cannot be broken
  down into simpler substances.
• The atoms of any element are alike, but are
  different from atoms of other elements.

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• Combinations of two or more elements chemically
  bonded together are called compounds.
• Combinations of two or more atoms chemically
  bonded together are called molecules.
• Molecules are the smallest units of compounds.
• Draw and label a water molecule.
• Draw and label a carbon dioxide molecule.

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• Many of the compounds found in living things are
  contain Carbon.
• These are called Organic Compounds.
• Organic compounds contain Carbon.
• Here are some of the most important organic
  compounds for living things

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The Arrangement of Organisms

• Atoms make ____________, which...
• make __________________, which...
• make __________________, which...
• make __________________, which...
• make __________________, which...
• make __________________.

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Proteins

• Contain C, H, N, O, and S
• Make up cell membranes, organelles, and other
  cell parts
• Made up of smaller molecules called Amino Acids.
• ENZYMES are proteins that control chemical
  reactions in an organism.

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Carbohydrates

• Contain C, H, and O
• Form cell walls and cell membranes.
• Energy rich food
• Sugar is a carbohydrate
• Sugar molecules can combine to form large
  molecules called starches.
• Plants store energy in starches.

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Lipids

• Contain C, H, and O
• Energy rich. Contain more energy than
  carbohydrates.
• Fats, oils and waxes are all lipids.
• Organisms store energy in fats.

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Nucleic Acids

• Made of C, H, N, O, and P (phosphorus).
• Very large organic molecules.
• DNA and RNA are Nucleic Acids.
• DNA contains genes that pass from a parent to its
  offspring.
• DNA also directs all a cells functions.
• RNA gives directions to the ribosomes to make
  specific proteins.

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Water and Cell Processes

• Without water, most of the chemical reactions
  required for life would not take place.
• Diffusion is the movement of molecules from areas
  of _____________ concentration to areas of
  ____________ concentration.
• Osmosis is the diffusion of water through a
  selectively permeable membrane.
• Most materials enter and leave a cell by
  diffusion through water.
• Diffusion and osmosis are both examples of
  _____________ transport.
• When a cell uses transport proteins or engulfing
  to acquire materials, this is called
  _____________ transport, and it requires
  _______________ .

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QUESTIONS FOR YOU

• How do photosynthesis and respiration form a
  cycle? Use these words in your answer molecules,
  raw materials, products.
• What is a system, and how is the cell a system?
• Compare the cell and these organelles to a
  factory nucleus, cell membrane, ribosomes,
  mitochondria.

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QUESTIONS FOR YOU

• How are the following words related cell, atom,
  molecule, organ system, organ, organism, tissue?
• How might the cell of the villae of the small
  intestine be different from the cell of an elodea
  leaf?
• How does the energy you got from your breakfast
  come from the sun?

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QUESTIONS FOR YOU

• How is osmosis different from diffusion?
• Draw a diagram of, and label how a cell shrinks
  when put into salt water. Explain the process
  using these words pore, diffusion, osmosis,
  selectively permeable membrane, salt molecule,
  water molecule.
• How does osmosis and diffusion help the cells of
  your body?