Outline of Lecture #1

Cell

    Definition

-Basic unit of structure for all living organisms
-Also fundamental unit of reproduction and function
-All cells physically defined by cell membrane that controls movement of stuff in and out
-Usually, but not always, easy to tell where one cell ends and another begins
Early observations
    Robert Hooke (1665) ó dead plant cells. Coined term "cell."

    Cell versus organism

Yeast (a fungus) and many bacteria are single-celled (unicellular) organisms
Human individual is an organism comprised of a trillion cells (multicellular).
Cell Diversity

        Size

-Cell size range: 1 micrometer - 200 micrometers.
-Advantages of being small: large surface to volume ratio, so things can be moved in and out efficiently. Also, diffusion time to center of cell is low
-Advantages of being large: Can compartmentalize functions.
-Advantages of being long: Single nucleus can maintain control over large distance. Can conduct fluids or signals unobstructed.         Differentiation and specialization -Shape, structure and biochemistry often reflect function
-Examples: red blood cell, nerve cells, rod cell, phloem and xylem cells of plants
-Some cells are dead at maturity (e.g. xylem cells)
-Red blood cells lose nucleus and important functions         Prokaryotes (procaryotes) versus eukaryotes (eucaryotes)

Cell structure

-Cell membrane
-Cell wall (Plants, fungi, bacteria)
-Plants and animals differ in terms of how adjacent cells are in contact with one another


Slides shown

All from Alberts et al.

Figures 1-21, 1-22, 15-1, 15-20, 15-26

Panels 1-2, 1-3 ("germ cells" only)