Cell Cycle

Mitosis

Division of the nucleus

Somatic cell division

Duplicated DNA is distributed evenly between two daughter cells

Cytokinesis

Finished product of Mitosis

Division of cytoplasm to form two separate cells

Interphase

Where a cell spends most of its time carrying out normal functions

Time spent here determines rate of division

G1, S phase, G2

DNA exists as chromatin- thread like mass

G1

Cell replicates organelles and increases volume of cytosol

S phase

DNA duplication performed

At end cell contains two identical sets of chromosomes

G2

Centrioles (cell division machinery) prepare to enter Mitosis

Prophase

Nuclear envelope disappears

Nucleolus disappears

Centrioles migrate to opposite poles and form spindle fibers

Metaphase

Chromosomes align equator

Cell has a total of 4 chromosomes (sister chromatid)

Anaphase

Chromosomes and centromere split

Chromosomes are pulled to opposite sides of cell

Chromosome movement stops after arriving near centrioles

Telephase

Marks end of Mitosis- nuclear division over

Nuclear membrane reforms

Chromosomes uncoil

Cleavage furrow

Human cells

2 types

Somatic cells

Sex cells (gametes)

Plasma membrane

outside the cell

lipid bilayer separates inside of cell from surrounding extra cellular fluid (semi permeable)

42% lipids, 55% proteins, 3% carbohydrates

Channel proteins— tiny tunnels, let specific ions pass through whether sm/lg or charged

Cytoplasm

Subdivisions- cytosol: liquid component, organelles: intracellular structures

Nucleus

“The brains”

Control center

DNA is kept

Diffusion (passive)

no energy expenditure by the cell

molecules of a substance move from an area of high concentration to low

3 types of diffusion

1 Simple- substances can directly penetrate plasma membrane

2 Channel mediated- used for passage of charged molecules and ions (not as easy to pass through)

3 Osmosis- referring to the diffusion of water only