Cell Communication Flashcards Preview

Bio 1610 Pittilleri > Cell Communication > Flashcards

Flashcards in Cell Communication Deck (33):
1

Direct Contact Communication

2 cells directly communicating
--they have to touch

2

Types of Direct Contact Communication

-Gap Junctions / Plasmadesmata
-Cell Recognition

3

Cell Recognition

involves proteins in the membrane.
-the proteins recognize each other and often a reaction happens with an enzyme

4

Functional Syncytium

All the cells are functioning as one unit

5

Local Signaling

Paracrine signaling
autocrine signaling
Synaptic Signaling

6

Paracrine Signaling

A cell releases a signal affecting all kinds of cells in an area
-the cell secretes a chemical that affects nearby cells through the interstitial fluid

7

Autocrine Signaling

a cell releases a signal affecting cells that are the same type

8

Synaptic Signaling

nerve cells release neurotransmitters directly onto target cells
-Affects one and only one cell

9

synapse

association between two cells (synaptic cleft)

10

Long- Distance Signaling

Endocrine (hormone)

11

Endocrine

Hormones are the chemical signal
-the cell releases the hormone into the blood
-it is systemic
-only targets cells that have receptors

12

Systemic

the whole body
--it will travel everywhere in the body

13

the 3 stages of cell signaling

1. Reception
2. Transduciton
3. Cell Response

14

Reception

Signal molecules (Ligand) bind to protein receptors on the target cell membrane.
--it is very specific

15

Ligand

is the chemical signal in reception
-hormones (protein or amino acid bases)
-neurotransmitters

16

Receptors

-Proteins
-specific (shape)
-shape changes when the Ligand binds--initiates transduction
-the receptor determines the response more than the ligand
--they will set off different transduction pathways in different cells

17

Types of Receptors

-Ion Channel Receptors
-Tyrosine Kinases
-G protein-coupled receptor

18

Ion Channel Receptor

Protein is the receptor and ion channel
-the binding of the ligand causes the channel to open

19

Receptor Tyrosine Kinases

-Come in pairs
- receptor tyrosine phosphoralates proteins
-receptor is a kinase which in turn activates proteins

20

G protein-coupled receptor

-receptor activates G protein (uses GDP to activate)
-G protein activates the enzyme

21

Transduction

Interactions/chemical reactions relaying the signal from the receptor to the target molecule
-can be very simple process of a long pathway of reactions
1. Phosphorylation/Dephosphorylation
2. Second Messengers

22

Phosphorylation / Dephosphorylation

addition or removal of a phosphate group to a protein to activate / deactivate it
-Kinases- Phosphorolayte
-Phosphates- dephosphorlayte enzymes

23

Second Messengers

small, non-protein, water-soluble, molecules, or ions
-often initiated by G protein-coupled receptors

24

Types of Second Messengers

-Cyclic AMP
-Calcium Ions (Ca++)

25

Cyclic AMP

they are cycle shaped AMP
- APT-----AMP ATP, gives off 2 phosphates to make AMP

26

Calcium Ions (Ca++)

Always maintained at low to negligible concentration in the cytosol
-pulled in form outside the cell or released from within the cell from enclosed membrane storage sights when calcium is needed

27

Response

Will vary depending on the Ligand/receptor/cell
-make more or less of something
-movement
-increase/decrease cells function
--very specific

28

Termination of signal / response

Varies with ligand/responses
-ligand- re-sequestered by cell, dissipate, brokendown...
-Response- Components of transduction used up or feedback mechanisms

29

Exception to Ligand-Reception communication

Steroid Hormones
-they are lipid soluble compounds that can pass right through the cell membrane
-they go directly to the nucleus and affect the DNA
--makes new proteins or stops cells from making new proteins

30

APOPTOSIS

Programmed cell death
-normal deletion and removal of cells
-happens to a single select cell
-external initiation/trigger- chemical signal???
--don't know much about it
-Internal trigger
--DNA damage
--problems with protein production

31

Necrosis

Something the body has not intended to happen.
-Usually happens to many cells in the same area
-Ruptures the cell membrane
-Very messie

32

Process of APOPTOSIS

-Cell releases digestive enzymes
-cell is broken down into smaller membrane bound fragments
-phagocytosis of fragments by nearby cells
-clean no inflamation

33

Diseases Affecting APOPTOSIS

- Hepatitis B & C
- Alzheimer's / Parkinson's
- Cancer - APOPTOSIS seems to be turned off