CELL COMPONENTS


Cells are the structural and functional units of life. The smallest organisms are composed of only a single cell while the largest are made up of billions of cells.

What is the structural and functional unit of life?

All cells come from what?

 

  Cells Are Small
       
Why do cells remain small?

       
Two types of cells distinguish two fundamentally distinct groups of organisms 

    A. Prokaryotes (before, nucleus) - no nucleus, i.e. DNA not membrane bound


    B. Eukaryotes (true, nucleus) - have a nucleus, i.e. DNA membrane bound
    C.  Major differences between prokaryotes and eukaryotes

 

Prokaryotes Eukaryotes
1. Nucleus no yes
2. Membrane bound organelles no yes
3. DNA (hereditary material) loop (no proteins) chromosomes (DNA + protein)

    What are the 3 basic difference between prokaryote and eukaryote cells?

       The internal organization in the eukaryotic cell allows a separation of what?

                

 



   Plasma membrane 

               
       

The plasma membrane is made up of what?

What makes up the fluid portion of the Fluid Mosaic Model of the Bilayer?

What makes up the mosaic portion of the Fluid Mosaic Model of the Bilayer?

What does it mean when we say the plasma membrane is selectively permeable?

Is the phospholipid's head polar or non-polar?  So is it hydrophobic or hydrophilic?  What about the fatty acid tails?

 

 

 


           
What substances can cross the membrane?  Why can non polar substances cross but not polar (excluding water)?  What is the name of the channels that allow water to cross the membrane?

What is diffusion?  Is diffusion fast or slow?  Is there an energy requirement for diffusion?  What is required to fuel movement of a substance against its concentration gradient?  What kind of transport is this called?

           

   Cytoplasm - semi fluid ground substance of the cell
        1. Forms most of the cell mass
        2. About 70% water

Most of the cell mass is made up of what?  What substance makes up most of the cytoplasm?

   Nucleus - control center of the cell

              
       
What is contained in the nucleus?  The nucleolus is responsible for ____________ assembly?  What nucleic acid is responsible for transfer of information from the nucleus to the rest of the cell?


  Endomembrane system - elaborate series of intracellular membranes that compartmentalize the cell
        1. Endoplasmic reticulum

Why is rough ER rough?  Ribosomes have a role in what? 

Where do you find smooth ER?  Smooth ER has a role in synthesis of what?
           
           Rough ER - has ribosomes attached
           Smooth ER - lacks ribosomes; site of various synthetic processes, , and storage; smooth ER forms transport vesicles. 

       

Golgi apparatus 

The golgi apparatus is responsible for what in the cell?


           

      Lysosomes 

Lysosomes contain a hydrolytic enzyme that allow them to do what?


               
       

Mitochondria - cell powerhouses

The mitochondria are responsible for producing what?  Mitochondria have their own DNA.  This leads scientists to believe what?

Aerobic respiration produces how many ATP from one molecule of glucose?


           

   Cytoskeleton - 3-D network of protein fibers which provides structural framework for the cell and suspends the organelles

Cell structure comes from what?


    Cilia and Flagella
        1. Cilia - short, usually numerous hair like projections that can move in an undulating fashion (e.g., Paramecium, lining of human upper respiratory tract)

        2.. Flagella - longer, usually fewer, whip-like projections that move in whip-like fashion (e.g., sperm cells)

      

Cilia moves what?  A flagella moves what?

Some of the structures found in a Eukaryotic cell and their proposed functions 

STRUCTURE  SOME OF PROPOSED FUNCTIONS
Cell Membrane Regulation of passage of materials into and out of the cell
Cell Wall Protection and maintenance of cell shape
Nucleus Contains most of the hereditary material (DNA) of the cell        Know this
Nucleolus Involved in the synthesis of ribosomes which then travel to the cytoplasm  Know this
Endoplasmic reticulum Synthesis and intracellular storage and transport of materials such as carbohydrates, proteins and steroids
Golgi Body Synthesis and secretion (often to the outside of the cell) of materials such as carbohydrates and proteins  Know this
Mitochondrion Derives chemical energy (in form of ATP) from organic materials for use by rest of cell (respiration)  Know this
Microbodies Various functions, depending on type, including fat breakdown and the packaging of "suicidal" hydrolytic enzymes (e.g. lysosomes)
Microtubules Maintenance of cell shape (where there is no cell wall), formation of "tracks" along which organelles can run, and formation of the spindle during cell division  Know this
Centrioles A group of microtubules which provide the base on which a flagellum can develop
Flagellum (Cilium) Provides motility, primarily for single-celled organisms. (Where an organism has more than 2 flagella, each is then known as a cilium)
Ribosome Site of protein synthesis     Know this
Vacuole Storage of substances (plants), site of digestion of particulate food (food vacuoles) in lower animals