Chapter 4 (Fall2010)

6 Pages
Unlock Document

Biological Sciences
Mary Olaveson

BIOA01FALL2010 CHAPTER 4 CELLSTHE WORKING UNITS OF LIFECell Theory cells are the fundamental units of life all organisms are composed of cells all cells come from preexisting cells7 characteristics of living things consist of organized cells contain heritable genetic info for reproduction show growth and development respondto environmental stimuli evolution maintain homeostasis useconvert energy and matter for biological function metabolism adapt to environmental change natural selectionevolution CELL SIZE IS LIMITED BY THE SURFACE AREATOVOLUME RATIOVolumes of cells range from 11000 cubic micrometersas V increases SA increasesthe volume of a cell determines the amount of chemical activity it carries out per unit of timethe surface area of a cell determines the amount of substances the cell can take in from outside environment and the amount of waste products it can release to the environmentthe smaller the cell the more efficient not as much waste lower need for resources easier transportation within the cell etccompartmentalization is key to eukaryotes MICROSCOPEScan visualize 02mmresolution the distance apart 2 objects must be in order for the eye to distinguish them as separate if they are closer together they appear as a single blurlight microscope allows visualization of cell sizes and shapes and some internal cell structures 1000 times what the eye can seeelectron microscope permits the details of many subcellular structures to be seen 1 million times what the eye can see CELL CHARACTERISTICSthese characteristics are of cells in all life therefore suggesting life comes from one source and has evolved through the yearscellularbased on on aqueous solutions6 elements C H N O P and SSimilar macromoleculesRNA and DNA from same nucleotidesGenome composed of RNA and DNAHave ribosomes acting as sites of protein synthesisUndergo metabolic reactions catalyzed by proteins ATPOsmotically active membranes of similar structureUse formationhydrolysis of ATP for energy flow CELLS ARE SURROUNDED BY A PLASMA MEMBRANEplasma membrane membrane that separates the cell from its environment creating a separate compartmentcomposed of phospholipid bylayer with the hydrophilic heads facing the aquous interior on one side of the membrane and the extracellular fluid on the other sideallows the cell to maintain a constant internal environmentacts as a selectively permeable barrier preventing or permitting some substances from entering or exiting the cell communication with adjacent cells and recives signals from the environmentcontains proteins that are responsible for binding and adhering to adjacent cells CELLS ARE PROKARYOTIC OR EUKARYOTIC
More Less

Related notes for BIOA01H3

Log In


Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.