CELL STRUCTURE AND FUNCTION

     

I   Cell

            A.  Definitions

            B.  Plasmalemma

                        1.  compartmentalization

                        2.  structure

                                    a.  lipid bilayer

                                    b.  proteins

                                    c.  semipermeable

                        3.  crossing the membrane

                                    a.  passive transport (with concentration gradient)    

                                                1.  diffusion 

                                                                                     Animation: How Diffusion Works                                                       

                                                            a.  osmosis (water)

                                                                        1.  hypertonic

                                                                        2.  hypotonic

                                                                        3.  isotonic

                                                2.  facilitated diffusion (protein pore)

                                    b.  active transport (with ATP and protein carrier)

            C.  Cytoplasm

                        1.  definition:   cytosol + organelles

                        2.  cytoskeleton

                        3.  organelles (small compartments)

                                    a.  mitochondria

                                                1.  “powerhouse of cell” - energy production

                                                2.  cell respiration:  glucose + oxygen ---> carbon dioxide + water + energy (ATP)                               

                                    b.  membrane networks

                                                1.  rough endoplasmic reticulum (RER) - protein synthesis

                                                2.  smooth endoplasmic reticulum (SER) - lipid synthesis

                                                3.  Golgi apparatus - protein sorting and packaging

                                    c.  lysosomes

                                                1.  “demolition sites” - microdigestive system

            D.  Nucleus

                        1.  DNA (deoxyribonucleic acid)

                                    a.  chromosomes vs. chromatin

                       2.  replication   (DNA to DNA)

                       3.  “command central”

                       4.  genes

            E.  Protein synthesis events

                         1.  DNA recipe copied on to RNA molecule = (mRNA) = transcription

                        2.  mRNA exit nucleus to ribosome

                        3.  transfer RNA (tRNA) with amino acid joins mRNA at ribosome = translation

 

 

       

       When you have finished this unit, you should be able to:

     

-   describe the structure of the plasma membrane

-   explain the function of the plasma membrane

-   explain why a substance crosses a membrane passively

-   define hypertonic, hypotonic, isotonic

-   explain why and how a substance crosses a membrane actively 

-   contrast diffusion and osmosis

-   given specific conditions, determine if a substance will cross a membrane

-   list the different components of the cytoskeleton and explain how they differ

-   name the organelles in the cell and state the function of each  

-   define cell respiration and where it occurs in the cell

-   define a "gene"

-   describe the role of DNA and RNA in making a protein

-   compare and contrast transcription and translation

   

 

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