Biological Science: All About Cells

Only available on StudyMode
  • Download(s) : 36
  • Published : February 14, 2013
Open Document
Text Preview
BIOLOGICAL SCIENCE
ALL ABOUT CELLS
NSC043 Lecture 3

What is a CELL?
—  Basic

structural unit of all living organisms —  microscopic —  “all life forms are composed of cells and product of cells” —  All functions essential to life occur at the cellular level

1
 

Phagocytosis, Pinocytosis, and microvilli

CYTOPLASM
—  Collective

term for cytosol and organelles contained within —  Colloidal suspension —  Cytosol mainly composed of water with free-floating molecules —  Viscosity constantly changes —  “Cytoplasm is like egg whites It’s very fluid and jelly —like Parts in the cytoplasm — organelles Are like baby organs inside of a cell”

ORGANELLES
—  Numerous

membranous compartments

◦  Compartmentalized = doesn’t interfere with others ◦  But there is still communication —  “Little

organs” —  Contains chemical systems that perform a variety of functions

"Cells Are Us"  —  Cells contain certain smaller structures, known as organelles. —  They perform the work of cells. —  Organelles are thus one level of organization for life functions.

2
 

Animal & Plant CELL

comparison

PROKARYOTIC vs. EUKARYOTIC
— 

Cells with NO definite membrane & membrane systems

— 

Cells WITH membranes and a definite nucleus

3
 

How do cells divide?
—  PROKARYOTES

◦  Binary Fission
–  Prokaryotic chromosome contains mostly DNA and some associated proteins Asexual reproduction requires a single parent; offspring are genetically identical to parent.

EUKARYOTES Meiosis and Mitosis
— 

MEIOSIS
— 

Meiosis is essential for sexual reproduction and therefore occurs in all eukaryotes

— 

MITOSIS —  process in which a eukaryotic cell separates the chromosomes in its cell nucleus into two identical sets in two daughter nuclei. —  It is generally followed immediately by cytokinesis which divides the nuclei, cytoplasm, organelles and cell membrane into two daughter cells containing roughly...
tracking img