Overview of Plant Physiology  

Definition - The study of how plants function in
terms of known chemical and physical laws

The plant cell  

Plant cells are surrounded by a rigid cell wall

  

 

   

  

 

Components:  

1. Protoplasm- aqueous solution of chemicals
2. Plasma membrane
      a. selectively permeable
        1. Controls exchange of materials with
           the environment
      b. Is a lipid bilayer

     

            

 

     c. Contain integral and peripheral proteins
       1. integral - may be in the lipid bilayer
          or embedded in the bilayer
       2. peripheral - on the outer or inner
         
surface of the membrane
    
  3. Organelles

 ENDOPLASMIC RETICULUM (ER)

  A SYSTEM OF MEMBRANES WITHIN THE CELL  

   COMPOUND OF FLATTENED TUBES AND SACS

TWO TYPES OF ER

    ROUGH ER  - COVERED WITH RIBOSOMES  

    SMOOTH ER - NO RIBOSOMES ATTACHED

TWO FUNCTIONS

ROUGH ER  - SITE OF SOME PROTEIN SYNTHESIS

SMOOTH ER - SYNTHESIS OF PHOSPHOLIPIDS FOR
            ASSEMBLY OF NEW MEMBRANES

DICTYOSOMES (GOLGI BODIES)  

STACKS OF FLATTENED, MEMBRANE SACS

RECEIVE MATERIAL FROM THE SMOOTH ER

MODIFY COMPONENTS RECEIVED FROM THE ER (ADD SUGARS)-

     GLYCOPROTEINS - PROTEIN + SUGAR

MICROBODIES

CHLOROPLASTS

MITOCHONDRIA

 

VACUOLE

 

 

CHANGES IN SIZE

CELLS AND TISSUES  

1. EPIDERMIS - LAYER OVER THE SURFACE OF THE PLANT BODY. FUNCTIONS IN PROTECTION FROM DESICCATION

BROKEN BY PORES THAT REGULATE THE MOVEMENT OF WATER OUT OF THE PLANT

2. PARENCHYMA

   a. PHOTOSYNTHESIS

   b. STORAGE

   c. WOUND HEALING

   d. THIN PRIMARY CELL WALLS

3. SUPORTING TISSUES

   a. COLLENCHYMA

      - HAVE THICK PRIMARY CELL WALLS

   b. SCLERENCHYMA

      - HAVE THICK SECONDARY CELL WALLS

      - TWO TYPES

        1. SCLERIDS

        2. FIBERS

4. VASCULAR TISSUES

   FUNCTION TO DISTRIBUTE WATER, MINERALS AND THE  
   PRODUCTS OF PHOTOSYNTHESIS

   TWO TYPES:

      XYLEM - COMPOSED OF TRACHEIDS, VESSEL               ELEMENTS & (PARENCHYMA CELLS)

            - DEAD AT MATURITY

            - HAVE THICK SECONDARY CELL
             
WALLS

 

      PHLOEM - TRANSPORT MOLECULES BETWEEN SOURCE AND
               SINK

             - COMPOSED OF SIEVE CELLS AND COMPANION                   CELLS,(SCLERIDS AND FIBERS)

             - ALIVE AT MATURITY 

    PLANT ORGANS

            - ROOTS

            - STEMS

            - LEAVES

            - FLOWERS

            - FRUITS

 

   FUNCTIONS-

   ROOTS -  ANCHOR THE PLANT

        -  STORE PHOTOSYNTHATE

        -  ABSORB WATER AND MINERAL NUTRIENTS     

   STEMS -  SUPPORT LEAVES

        -  CONDUCT NUTRIENTS & WATER  

   LEAVES- PHOTOSYNTHESIS