Biology Unit 2: Test Review Essay

Submitted By laurenleg
Words: 328
Pages: 2

Estrogen & the cell:
Lipid estrogen enters the target cell by simple diffusion
Estrogen binds to clusters of estrogen protein receptors
This activated estrogen-estrogen receptor (E-ER) travels into the cell’s nucleus
The estrogen-estrogen receptor then binds to the estrogen response element (((( this is near the promoter, but can act to either stimulate OR turn off transcription))))

Estrogen goes straight across cells bc it’s a steroid molecule
Hydrophilic molecules don’t go straight across... they pass thru proteins that are embedded in the cell membrane ex. water, glucose

Too much estrogen can lead to cancer

Estrogen only stays in target cells like brain, heart, liver, uterus, breasts

Estrogen temporarily causes cells to change unlike harmful mutations like mercury that permanently alter the cells

Mutations: permanent changes in DNA sequence… result in DNA that cannot be duplicated and must be repaired; bind to receptors, NOT directly to DNA; if a cell is mutated AND exposed to estrogen then the cell speeds up
Cancer arises from DNA mutations in cells—cells rapidly reproduce ex. changing a T to an A

ALL CELLS HAVE THE SAME GENES/ genome but different gene expression (mRNA & proteins)

Benefits of estrogen: development of breast & uterine tissues, preserves bone strength, controls cholesterol

 Middle of menstrual cycle- lots of breast cell proliferation/reproducing bc lots of estrogen and at the end of menstrual cycle- breast cell death bc low estrogen

How to…