Unit 4 Flashcards
What are the different types of Cell Communications? (4)
- Direct cell-cell communications
- Paracrine
- Endocrine
- Autocrine
How does direct cell-cell communication work?
A cell touches another cell, the protein link
the gap is called
animal = gap junction
plant = plasmodesmata
Paracrine?
Short Distance communication
Synaptic = use of neurons
Endocrine?
Long distance communications
Autocrine
Receptor bind to its own Ligand
What are the three types of membrane CELL SURFACE receptors?
- Ligand - gated ion channels
- G-protein coupled receptors
- Enzyme linked receptors
Ligand gated ion channels
The receptor binds to the ligand, opening up a ion channel
Enzyme linked receptors
An enzyme binds to its substrate, setting off a chain of reactions in the cell
G-Protein
Review chart
Primary Messenger
A ligand that binds to a receptor on the outside of the cell, setting off a chain of reactions
Secondary Messenger
the ligand that is set off by the primary messenger, making the game of telephone happen
Gain of Function
A mutation in the cell which makes the reaction occur without the receptor binding to the ligand
Loss of Function
A mutation in the cell which makes the reaction NOT occur even when the receptor binds to the ligand
Homeostatis
Tendency to go to stable internal enviorment
Positive Feedback Loop
Amplifies stimulus
Negative Feedback Loop (4 parts)
Stimulus - thing happens
sensor - thing is noticed
control - reduce that thing
effector - back to normal
Set Point
The stable target value
Stimulus
Trigger for feedback / “cue”
decondensed
“stringy”
condensed
not stringy, compact
What’s wrong with cancer cells? (4)
- Constantly reproduce cells
- Cells have damaged DNA
- They don’t die
- They spread
autosomes
Non-sex chromosomes
signal relay pathway
game of telephone with ligand and receptors
what do we mean by ligand is turned on?
Phosphorylation - ADP is converted to ATP with the help of enzyme Kinase
Cell Cycle
The Cell must reproduce, so it goes through multiple phases in order to do this
These phases are called
1. Interphase
2. Mitosis
Interphase
The interphase is the phase in the cell cycle where the DNA is duplicated and where it grows
It is made up of
- G-one (grows)
- S phase (chromatin grows and the DNA duplicates)
- G two (grows some more)
Mitosis
Mitosis goes through many phases in order to ultimately split the cell into two, identical daughter cells
Taxis
movement of an organism in response to a stimulus
chemotaxis
a type of taxis that responses to a CHEMICAL stimulus
Signal transduction
external signal is transmitted to the inside of the cell
What are the three steps for signal transduction?
- A signaling molecule binding to a specific receptor
- activation of signal transduction pathway
- production of cellular response
salinity
containing salts or mg
centromere
the place where the sister chromatids are linked
apoptosis
programed for death
oncogenes
mutated cancer cells
tumor suppressor genes
produce proteins that prevent normal cells turning into cancer cells
kinetochore
the place where the spindle attaches during prophase
cleavage furrow
the part where the cell is split during telophase for animal cells
cell plate
the part where the cell is split during telophase for plants
disjunction
the process where chromosomes separate and move apart towards opposite poles of a cell during cell division
quorum sensing
a process of cell-to-cell communication that allows bacteria to sense their population density and adjust their gene expression
juxtacrince signaling
direct cell to cell communication
