5.1 Movement of Substances
 

-maintaining a relatively constant internal
   cell environment is essential for life

-several processes need to occur in the
   cell in order to maintain this homeostasis
 

cell membrane

passive
-no cellular energy is used
-e.g. diffusion, osmosis

active
-requires energy
-"pumps" material from low concentration
    to a higher concentration
-large protein particles in the cell
    membrane are involved and are called
    "carriers"
 
 

DIFFUSION
-form of passive transport
-material goes from higher concentration
    to a lower concentration
 

5.2 Energy Processes

-all animals depend on other organisms to
    obtain energy

-plants do not depend on other organisms
 

PHOTOSYNTHESIS
-plants get their energy through the
    process of photosynthesis
- means "putting together with light"

• takes place in chloroplasts
• chlorophyll in the chloroplasts trap the light energy
• the chemical reaction:

                        Reactants                                    Products
 

• takes air (CO_{2 ,} water) and sun's energy [Reactants]
• makes sugar (glucose) and oxygen [Products]
• light energy is converted to chemical energy
• chemical energy is stored as glucose or starch in leaves and seeds

• occurs in both plants and animal cells
• releases the stored energy of glucose
• the chemical reaction:

   Reactants                            Products
 
• gives off Carbon dioxide, water, and energy in the form of ATP (Products)
• ATP carries energy throughout the organism

• occurs when cells break down glucose without oxygen
• either alcohol or lactic acid is produced and a small amount of ATP

• muscle cramps:
• caused by fermentation
• lack of enough oxygen from exertion
• stored glycogen is converted to lactic acid
• sometimes the lactic acid builds up (accumulates) causing cramps or soreness of muscles

5.3 Cell Growth and Division

CELL DIVISION

cell division   - process during which your
                        body makes new cells
                     - two identical cells are
                        produced
                     - in single-celled organisms,
                       two new organisms are
                       formed

CYCLE OF CELL GROWTH

[see Fig. 5.7 p 103 in textbook]

- most of a cell's life is spent in the phase
    of growth and development called
    interphase
-cell doubles in size during interphase

mitosis - when cell nucleus divides into two
                identical nuclei

chromosomes - threadlike strands in the nucleus that controls cell activity and carry the genetic material (DNA)

FOUR STEPS OF MITOSIS: (in order)

PROPHASE -first step in mitosis

METAPHASE - second step

ANAPHASE -third step

TELOPHASE -final step of mitosis
   -phase of mitosis when cell divides
            into two new cells
   -two identical nuclei exist

Make up a mnemonic to remember order, e.g.
"propose meeting and television"
      or just "pmat"
your mnemonic:
 
 

    [OH#12 Phases of Cell Cycle, part a]
  [OH#13 Phases of Cell Cycle, part b]

See Fig. 5.8 Animal Cell Cycle pg104 & 105 in Text book

For the test

• STUDY THESE NOTES
• STUDY NOTE CARDS
• ALSO--Read "Science and Society" for each section 5.1, 5.2, and 5.3, pgs. 96, 101, 106.  There will be one question about this material from each section, i.e.--3 questions.