PHASES OF CELL CYCLE

Interphase

• “resting phase”

• longest phase

G1

Period prior to DNA synthesis

S

period of actual DNA synthesis

G2

• period after DNA synthesis

• the cell is now ready to eter the cell division phase

Prophase

chromosomes thicken and become visible while the nuclear membrane & nucleolus disappear

Metaphase

Chromosomes line up along equatorial plane

Anaphase

chromosomes attach to spindle fibers & move toward opposite poles

Telophase

each chromatids form separated chromosomes become the chromatids of daughter cells, and the nuclear membrane and nucleolus reappear

Cell membrane

• aka “plasma membrane”

• regulates inflow & outflow of cytoplasmic substances

Nucleus

• contains genetic materials

• DNA in chromosomes, RNA in nucleolus, nuclear sao & nuclear envelope

Mitochondrion

• boat or sausage shaped

• regarded as the powerhouse of cell for it produces energy in the form of ATP thru Kreb’s cycle/citric/tricarboxylic acid cycle

Lysosome & peroxisome

contain hydrolytic & oxidative enzymes, respectively, for destroying foreig agents (esp in phagocytic cells capable of engulfing bacteria & viruses

Rough endoplasmic reticulum

• type of ER for protein synthesis

smooth endoplasmic reticulum

• type of ER for lipid, steroid and carbohydrate synthesis

Ribosome

freely suspended in cytoplasm; protein synthesis for internal use (lipoproteins, glycoproteins etc.)

Golgi apparatus

• “golgi body”, “golgi complex”

• packages secretory products of RER & SER prior to release out of cell

Centriole

Paired organelle which migrates to opposite poles during mitosis & meiosis and served to organize & guide to mitotic spindles during cell division processes