ALL ABOUT CELLS
NSC043 Lecture 3
What is a CELL?
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
Phagocytosis, Pinocytosis, and microvilli
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”
◦ 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.
Animal & Plant CELL
PROKARYOTIC vs. EUKARYOTIC
Cells with NO definite membrane & membrane systems
Cells WITH membranes and a definite nucleus
How do cells divide?
◦ 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 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...