Bio exam 3 chapter 11

Put the steps of the process of signal transduction in the order they occur 1. A confrontational change in the signal receptor complex activates an enzyme 2. Protein kinases are activated 3. A signal molecule binds to a receptor 4. Target proteins are phosphorylated 5. Second messenger molecules are released

3,1,5,2,4

Which component is a protein fiber of the extracellular matrix

A

What is a hormone act only unspecific cell types in an organism and not others?

A cell must have the appropriate receptor before it can bind the hormone

Not all inter cellular signals require transduction which one of the following signals would be processed without transduction

A lipid soluble bull signal

Pemphigus vulgaris is an autoimmune disorder in humans in which anti-bodies are produced against the cadherins of desmosomes. The blistering of the skin and mucous membranes characteristic of this disorder is probably a result of?

A loss in cell cell adhesion

Different body cells can respond differently to the same peptide hormones because_____

A target cells response is determined by the components of it signal transduction pathways

Protein kinase is an enzyme that____

Activates or inactivates other proteins by adding a phosphate group to them

Based on what you have learned about how celles ensure that proteins and up in the right place, what type of signal would you expect to be exposed a night Cytosolic receptor after steroid hormone changes the receptors conformation

Amino acids required for transport through the nuclear pore complex

A protein kinase activating many other protein kinase is an example of___.

Amplification

Steroid hormones bind the receptors inside the cell and alter their confirmation the hormone receptor complex is then transported into the nucleus where can directly affect gene expression to get from the location where the receptor binds the hormone to its sight of action the hormone receptor complex must-------

Be transported through the nuclear pore complex

What role does a transcription factor play in signal transduction pathway?

By binding to DNA it triggers the transcription of a specific gene

Which of these is activated by calcium ions?

Calmodulin

The most abundant protein found in the extracellular matrix of animal cells is

Collagen

Which of these acts as a second messenger?

Cyclic AMP

Which of these is not correct

Cyclic AMPbinds to calmodulin

Integrins are integral membrane proteins they are often attached to_____

Cytoskeleton proteins and proteins in the extracellular matrix

The primary role of____ is to bind animal cells together.

Desmosomes

The activation of receptor tyrosine kinase is characterized by

Dimerization and phosphorylation

Calcium ions that act as second messengers are stored in

Endoplasmic reticula

Because cell walls consist of a cross linked network of long filaments embedded in a stiff surrounding material they can be called

Fiber composites

A tocsin that inhibits the production of GTP would interfere with the function of the signal transduction pathway that is initiated by the binding of the signal molecule to______ receptors

G protein linked

Epinephrine acts as a signal molecule that touches to____ proteins

G protein linked receptor

Ions can travel directly from the cytoplasm of one animal cell to the cytoplasm of an adjacent cell through_____

Gap junctions

_____ Aid in the coordination of the activities of adjacent animal cells.

Gap junctions

The cleavage of glycogen by glycogen phosphorylase releases

Glucose one phosphate

A mutation that disrupts the ability of an animal cell to add polysaccharide modifications to protein would most likely cause defects in its

Golgi apparatus & extracellular matrix

Hormones are chemical substances produced in one organ that are released into the bloodstream and affect the function of a target organ for The target organ to respond to a particular hormone it must_____

Have receptors that recognize and bind the hormone molecule

Where would you expect to find tight junctions?

In the epithelium of an animal stomach

Signal transduction pathways

Include the intercellular events stimulated by and extracellular signal

Signals from the extracellular matrix to that cytoskeleton may be transmitted by

Integrins

Which of the following is characteristic of a steroid hormone action?

Internal receptor binding

A G protein receptor with GTP bound to it

Is in its active state

The most common on signal for activating proteins during the process of signal transduction is through the addition of a phosphate group by a_______ enzyme

Kinase

The signal molecule is also known as a

Ligand

Osteocytes are bone cells collagen fibers in calcium salts are found in abundance between and among the osteocytes the collagen and calcium salts are______

Part of the extracellular matrix

The receptors for steroid hormones and peptide hormones are fundamentally different because

Peptides are hydrophilic and steroids are hydrophobic

___ catalyzes the production of____. Which then open an ion channel that releases___ into the cells cytoplasm

Phospholipase C, IP3, Ca2+

Which statement is most accurate considering how the molecule composition of the plant cell wall compares with the ECM of animal cells

Plant cell wall fibers consist primarily of carbohydrates ECM fibers are dominated by proteins

It is well known that so Wells implants protect the cells from excessive uptake of water, but these balls also reserve as a barrier to viruses. It has been observed, however, that once a plant cell becomes infected, the viruses can easily move throughout the plant despite the fact that a ball surrounds each cell. Which structures enable a virus to infect an entire plant quickly?

Plasmodesmata

Which of the following statements most accurately describes the function of Plsmodesmata in plant cells or gap junctions in animal cells?

Plasmodesmata allow passage of proteins and small molecules between adjacent cells

For the experiment shown in figure 11.9, which answer correctly states the prediction of the hypothesis or null hypothesis?

Prediction of hypothesis, antibodies to some membrane proteins will block cell cell adhesions

One of the major categories of receptors in the plasma membrane reacts by forming dimers adding phosphate groups and then activating really proteins which type does this?

Receptor tyrosine kinase

In general a signal transmitted via phosphorylation of the series proteins_____

Results in a confirmational change to each protein

A signal transduction pathway is initiated when a ____ binds to a receptor

Signal molecule

A signal transduction pathway is initiated when a_____ binds to a receptor

Signal molecule

Which of the cell junctions form a barrier to the passage of materials?

Tight junctions

The receptors for steroid hormones are located inside the cell instead of on the membrane surface like most other signal receptors this is not a problem for steroids because____

Steroid hormones are lipid soluble so they can read it bleed diffuse through the lipid bilayer of the cell membrane

How does the function of the intercellular receptor differ from that of a membrane receptor

The intercellular receptor binds DNA or binds the transcription factor protein that binds to DNA

How can a hormone that is present in very small quantities within the bloodstream elict such a large response within a cell?

The message from the hormone is amplified many times within the cell

HV Wilson worked with sponges to gain some insight into exactly what was responsible for holding adjacent cells together he exposed two species of differently pigmented sponges to a chemical that disrupted the cell cell interaction in the cells of the sponges disassociated. Wilson then mix the cells of the two species and remove the chemical that cause the cells to disassociate Wilson found that the sponges reassembled into two separate species the cells from one species did not interact or form associations with the cells of the other species how do you explain the results of Wilson's experiment?

The molecules responsible for cell cell adhesion differ between the two species of sponge

Acetycholine is a Nero transmitter that binds to receptors on skeletal muscle cells the receptor signal complex brings about a series of events that result in contraction of the skeletal muscle them from black widow spiders cause an explosive release of acetycholine what with this do to victims?

The victims muscles would be unable to relax.

For a tissue organ organ to function as a unit_____

There must be cell cell communication among the cells within a tissue or Oregon

Which of these is the second of the three stages of cell signaling

Transduction

Intercalated disks are cell cell junctions found between cardiac muscle cells one feature of these intercalated discsis that they contain a large number of gap junctions which means that_____

Water ions and small molecules can readily pass from one cardiac muscle cell to the next

Phosphorylation cascades involving a series of protein kinase are useful for cellular signals transduction because they

amplify the original signal many times

Consider this pathway epinephine-> G protein coupled receptor -> G protein-> adenylyn cyclase -> cAmp The second messenger in this pathway is?

cAMP