Biology 1401 Chapter 9 Cell Communication
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- 1.Located on or within the cell are _________ proteins, each of which has a three dimensional shape complementary to that of a specific signal molecule.
- A.
Amplification
- B.
Monoclonal
- C.
Transmembranal
- D.
Receptor
- E.
Messenger
- 2.The space into which neurotransmitters are released is called a chemical
- A.
Synapse.
- B.
Junction.
- C.
Channel.
- D.
Desmosome.
- E.
Vesicle.
- 3.Which of the following is not a second messenger?
- A.
CAMP
- B.
Ca++ions
- C.
Diacyl glycerol (DAG)
- D.
Inositol-1,4,5-triphosphate (IP3)
- E.
Phospholipase C
- 4.Specific protein receptors are present for all of the following except
- A.
Signal amplification.
- B.
Signal transduction.
- C.
Intracellular receptors binding to DNA.
- D.
Signaling to other cells.
- E.
Cell junctions.
- 5.Communication between cells can occur by all of the following basic mechanisms except
- A.
Direct contact.
- B.
Intracellular signaling.
- C.
Paracrine signaling.
- D.
Endocrine signaling.
- E.
Synaptic signaling.
- 6.Signals with short-lived, local effects are called
- A.
Direct contact.
- B.
Endocrine signals.
- C.
Paracrine signals.
- D.
Synaptic signals.
- 7.Synaptic signaling requires which of the following to be released into the synaptic gap?
- A.
Hormones
- B.
Internal receptors
- C.
Genes
- D.
Neurotransmitters
- E.
Lipids
- 8.Signal molecules activate intracellular receptors in
- A.
Chromosomes.
- B.
Vesicles.
- C.
Target cells.
- D.
Skin cells.
- E.
Surface cells.
- 9.The molecules that convert extracellular signals into intracellular ones are
- A.
Neurotransmitters.
- B.
Peptide hormones.
- C.
Cell surface receptors.
- D.
Growth factor proteins.
- E.
Genes.
- 10.All of the following statements about chemically-gated ion channels are true except
- A.
Their amino acid chains wind back and forth across the membrane.
- B.
They close in response to binding of the signal molecule.
- C.
A pore exists in the center of the protein.
- D.
The pore connects the extracellular fluid with the cytoplasm.
- E.
The pore is big enough for ions to pass through it.
- 11.The class of cell surface receptors that acts indirectly on plasma membrane-bound enzymes or ion channels is called
- A.
G-protein-coupled receptors.
- B.
Gated ion channels.
- C.
Enzymatic receptors.
- D.
Second messenger receptors.
- 12.Which of following statements about G proteins associated with G-protein-coupled receptors is false?
- A.
G proteins provide a link between the receptor and effector protein.
- B.
G proteins can propagate the signal by either the G~ or the G(by) components.
- C.
G proteins are heterotrimeric.
- D.
Associated G proteins become active by exchanging GTP and GDP.
- E.
Activated G protein diffuses away from the receptor.
- 13.Which pair are examples of second messengers?
- A.
Sodium, potassium ions
- B.
Amino acids, proteins
- C.
Steroids, lipids
- D.
Sugars, starches
- E.
CAMP, calcium ions
- 14.A small number of surface receptors can ultimately generate a large intracellular response, as each step of the pathway is often expanded by
- A.
Enzymatic receptors.
- B.
Gated ion channels.
- C.
Signal amplification.
- D.
G-protein-coupled receptors.
- 15.Most cells are in physical contact with other cells at all times by forming permanent connections called
- A.
Cell junctions.
- B.
Gated ion channels.
- C.
Enzymatic receptors.
- D.
G-protein-coupled receptors.
- E.
Cell surface markers.
- 16.Small molecules or ions can pass from one cell to another through
- A.
Tight junctions.
- B.
Gap junctions.
- C.
Diffusion spheres.
- D.
Desmosomes.
- E.
Adherens junctions.
- 17.In plants, cell-cell junctions can only occur at gaps in the cell walls through cytoplasmic connections that form across the plasma membranes of the touching cells. These junctions are called
- A.
Desmosomes.
- B.
Tight junctions.
- C.
Plasmodesmata.
- D.
The cellulose matrix.
- E.
Adhering junctions.
- 18.Chemically-gated ion channels are receptor proteins through which ions pass. A cell biologist has blocked these channels in a lab rat's liver tissue by using a chemical that
- A.
Prohibits binding of a signal molecule.
- B.
Prohibits ions from entering the cell via active transport.
- C.
Causes ions to move in the opposite direction of the ion gradient.
- D.
Prohibits second messenger signaling.
- 19.What characteristics do all cell surface receptors share?
- A.
They are composed of hydrophilic proteins.
- B.
They all must bind to a molecule to be activated.
- C.
They all result in creation of an ion channel.
- D.
They include the activation of a G protein.
- 20.
- A.
Phosphate groups are efficient second messengers.
- B.
Protein kinase and phosphatases are abundant in most cells.
- C.
The hydolysis of bound GTP results in GDP and Pi.
- D.
The addition or removal of a phosphate group can expose or hide potential binding sites in proteins.
- 21.Which of the following proteins phosphorylates MAP kinase kinase?
- A.
MAP kinase
- B.
MAP kinase kinase
- C.
MAP kinase kinase kinase
- D.
MAP phosphatase
- 22.Long-lived; affects cells very distant from the releasing cell.
- A.
Paracrine signaling
- B.
Direct contact
- C.
Endoctine signaling
- D.
Synaptic signaling
- 23.Signal molecules on a cell membrane interact with molecules on a neighboring cell membrane.
- A.
Paracrine signaling
- B.
Direct contact
- C.
Endoctine signaling
- D.
Synaptic signaling
- 24.Short lived; used by nerve cells.
- A.
Paracrine signaling
- B.
Direct contact
- C.
Endoctine signaling
- D.
Synaptic signaling
- 25.Short-lived, causing local effects.
- A.
Paracrine signaling
- B.
Direct contact
- C.
Endoctine signaling
- D.
Synaptic signaling
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