Cell Biology

Cell Theory

Living organisms are made of one or more cells
Cells are the smallest unit of life
All cells come from pre-existing cells

There are exceptions to the Cell Theory.

ie. Red Blood Cells, Fungal Hyphae, Skeletal Muscle, Giant Algae

Functions of a cell

Metabolism
Excretion
Homeostasis
Reproduction
Growth
Nutrition
Response
Some ability to move

How single-celled organisms live

Function	Paramecium	Chlorella
Respiration	Diffusion of gases	By the diffusion of gases
Growth and Reproduction	Binary fission	Binary fission
Response	Surface sensitive to touch chemicals	Responds to light
Homeostasis	Excretory products diffuse out	Carbon dioxide leaves by diffusion
Nutrition	Feeds using cilia	Photosynthesis
Movement	Cilia propel organism	Floats in water

Stem Cells

Totipotent- Can form any cell type, embryonic tissue
Pluripotent- Can form any cell type
Multipotent- Can differentiate into a number of closely related cell types
Unipotent- Can not differentiate, capable of self-renewal
Embryonic- Come from a blastocyst, like totipotent

Type of Transport	Explanation	Active or Passive	Membrane component?	Examples of molecules
Endocytosisinto the cell	Phagocytosis- eatingPinocytosis-drinking	A	Infolding of Phosopolipid bilayer	WBC- Bacteria, Pathogens, Debris, FoodVitamins, Sugars
Exocytosis	Exit the cell	A	Vesicles from Golgi fuse	Proteins, Hormones, neurotransmitters
Simple Diffusion	Go with a concentration gradient	P	Through Phospholipid bilayer	O2, CO2non-polar substances
Facilitated Diffusion	Go with a concentration gradient	P	Protein channels or protein carrier	Glucose, amino acids, polar substances
Osmosis	The net movement of H2O	P	Protein channels, Aquaporins	H2O
Ion-exchange pump	Use energy to move molecules from low to high	A	Ion pumpsSodium/potassium pumps	NA+K+

Mitosis/Cell Cycle

Interphase-G1, S, G2, normal cell

Prophase- First stage, nuclear membrane disintegrates, chromosomes pair up, centrioles start to produce spindle fibers

Metaphase- Second phase, Spindle fibers attach to the kinetochore, chromosomes align on the metaphase plate

Anaphase- Third phase, spindle fibers separate pulling sister chromatids to opposite poles

Telophase- Final phase, spindle fibers disintegrate, daughter chromatids condense, cleavage furrow forms (animal) or cell plate forms (plant), nuclear membrane reforms

Cytokinesis- Returns to normal cell

Mitotic index= Cells in mitosis/total number of cells