Molecular Final - Communication

Front 1

First and Second messengers

Back 1

-first: ligand binds a cell surface receptor in plasma membrane

-second: acts in the cytoplasm

Front 2

G - proteins

Back 2

-link between 1st and 2nd messenger

-complex coupled to membrane receptor

-activated when ligand binds to receptor at membrane surface

Front 3

Amplification

Back 3

-magnifies effect of signal on target cell

-small number of signal molecules bind to membrane receptors

-leads to thousands of second messengers in cell

Front 4

How does phosphorylation of proteins produce a cellular response?

Back 4

-P of enzymes, structural proteins, transcription factors

-influence structure and function of cell

-increase energy production

Front 5

Types of cell communication

Back 5

1. direct inercellular

2. contact - dependent

3. autocrine

4. paracrine

5. endocrine

Front 6

How can differential gene regulation affect the cellular response?

Back 6

-differential expression of receptor or have a lot of it or have a little

-two receptors with diff. affinities for the signal

-different intracellular signal transduction proteins

-expression of proteins controlled by signal transduction pathways varies

Front 7

Indirect signaling

Back 7

-release of chemical messenger from signaling cell
-transport of messenger through extracellular environment of target cell
-communication of signal to target cell

Front 8

chemical messengers

Back 8

six classes:

-amino acids/proteins

-steroids

-amines

-lipids

-purines

-gases

Front 9

Growth hormone

Back 9

direct metabolic effects

indirect effects via IGf's on somatic growth

Front 10

How does cell communication influence and coordinate the development of a complex, multicellular organism?

Back 10

-genomes and proteomes

-metamorphosis

-secretion of thyroid hormone increases during metamorphosis

Front 11

Frog - stages of metamorphosis

Back 11

Tadpole - gills + skin for respiration, tail fin

Early - hindlimbs grow
Late - forelimbs grow, tail reabsorbed, eyes migrate

Froglet - terrestrial lungs + legs, frontal eyes

Front 12

Cells lost vs. cells gained during frog metamorphosis

Back 12

Gained: limbs - bone, muscle, connective tissue, blood vessels

Lost: tail - notochord, muscle, connective tissue, blood vessel

Trunk - little change

Front 13

How does the thyroid hormone work?

Back 13

-gland releases hormone

-travels through blood - transported across cell membrane

-binds to thyroid hormone receptor

Front 14

What happens in the nucleus after thyroid protein binds to receptor?

Back 14

In nucleus: hormone-receptor complex becomes a transcription factor and activates gene expression

Front 15

How do the legs of frogs grow?

Back 15

-mitosis

-cell differentiation - specialization of cells, produce new proteins

Front 16

How is the tail lost in tadpoles?

Back 16

Transcription factors (new proteins) trigger apoptosis

-cells die and tail is reabsorbed into the frog

Front 17

Transcription factor

Back 17

Ex: target cells with Thyroid hormone have receptor - hormone receptor complex = transcription factor

-Change gene expression allowing cells to become specialized - depends on concentration, receptor, development