AP BIO unit 4

Signal Transduction Pathway

Signal Transduction Pathway

converts signals on cells surface into cellular responses

Local regulators

messenger molecules that travel short distances (animal cells)

Long distance signaling

uses hormones (plant and animal cells)

Three stages of cell signaling

Receptions, Transduction, Response

Reception

signal molecule binds to receptor protein, causing it to change shape

Transduction

Amplification of signal through a multistep pathway

Response

causes synthesis of protein or regulation of protein activity

Cell divison is used for

growth, tissue renewal, reproduction

Mitosis

cell division of two indentical daughter cells

Somatic Cells

body cells, non reproductive

Gametes

sex cells, reproductive (half as many chromosomes as somatic)

Interphase

preperation for cell divison

Miotic Phase

divison of nucleus and cytoplasm

5 phases of Mitosis

Prophase, Prometaphase, Metaphase, Anaphase, Telophase

Cell Cycle Control System

directs events of cell cycle

G1 Checkpoint

cells will move on and divide or sent into nondividing stage called G0

G2 Checkpoint

checks for DNA damage and complete DNA replication

M Checkpoint

checks for completion of DNA replication

Binary Fission

reproductions of Prokaryotes

Internal Signals

non attached kinetochores send signal to delay anaphase

Growth Factors

released proteins from certain cells stimulate other cells to divide

Density-dependent Inhibtion

crowded cells stop dividing

Anchorage Dependence

cells must be attached to substratum to divide