Biology I: Chapter 9: McGraw Hill

Which of the following are the three subclasses of membrane receptors?

* Channel-linked receptors * enzymatic receptors * G protein-coupled receptors

The three functional domains of the steroid receptors can be described as which of the following?

* DNA-binding domain * Domain that affects the level of gene transcription * Hormone-binding domain

Identify two inositol phosphate compounds that act as second messengers.

* IP3 * DAG

Which of the following are molecules that can serve as signals in cell communication?

* Nucleotides * Individual amino acids * Peptides * Dissolves gases

Which of the following are ways in which intracellular receptors can act?

* They can act by producing changes in gene expression * They can be enzymatic receptors that modify molecules in the cytoplasm

Examples of second messengers include which of the following?

* cAMP * calcium

examples of steroids:

* estrogen * cortisol * testosterone

Two hormones that can stimulate liver cells to mobilize glucose are:

* glucagon * epinephrine

The three functional domains of the steroid receptors can be described as which of the following?

* hormone-binding domain * DNA-binding domain * domain that affects the level of gene transcription

Which of the following are molecules that can serve as signals in cell communication?

* individual amino acids * dissolved gases * peptides * nucleotides

What types of cell signaling occur between cells in early development?

* paracrine signaling * direct contact

Which of the following are processes that commonly occur during signal transduction?

* protein deactivation * protein activation

Based on the amino acid to which a phosphate groups is added, protein kinases can be

* serine/threonine kinases * tyrosine kinases

Order the steps of signaling via a GPCR as they occur in the cell (start at top).

1. Ligand binds to the receptor 2. Activation of G protein 3. Activation of effector protein 4. Cellular response

Order the steps in cell signaling as they occur in a cell:

1. Signal reception 2. Signal transduction 3. Cellular response

Order the different type of signals according to the time it takes for them to be broken down, from shortest (at the top) to longest (at the bottom).

1. neurotransmitters 2. water-soluble hormones 3. steroid hormones

Adenylyl cyclase takes _____________ as a substrate and coverts it to the second messenger __________________.

ATP; cAMP

Which of the following statements about the response of cells to signals in the surrounding environment is true?

Cells are usually exposed to many signals, but only respond to some of them.

_________________ proteins are intracellular proteins that interact with G-protein-coupled receptors.

G

Which of the three types of membrane receptors acts indirectly via a "helper" molecule?

G protein-coupled receptors

How are G protein-coupled receptors different from enzymatic receptors?

G protein-coupled receptors act indirectly with the help of an assisting protein

Identify intracellular proteins that bind guanosine triphosphate (GTP) and guanosine diphosphate (GDP). G proteins Fibrous proteins Plasma proteins

G proteins

What term is used to describe a signaling molecule?

Ligand

Which of the following best summarizes the function of G proteins?

They link GPCRs with effector proteins.

Which of the following statements regarding signal transduction pathways and the response of different cells to the same signal is true?

Two different cells can have different SDPs which allows them to respond differently to the same signaling molecule

Which of the following statements about signaling molecules and their action on different cells is true?

a single signal may or may not have different effects on different cells

One of the most common second messengers is ________________, which is produced from ATP.

cAMP (cyclic adenosine monophosphate)

Membrane receptors typically belong to one of three subclasses: __________________-linked receptors, _________________ receptors or G- ___________________ coupled receptors.

channel; enzymatic; protein

The association of a neuron and its target cell is called a __________ synapse.

chemical

In __________________ ____________________, the signal is a molecule located in the plasma membrane of one cell, while the receptor protein is located in the plasma membrane of another, adjacent cell.

direct contact

____________ proteins activated by G proteins in GPCRs are usually enzymes.

effector

Hormones, which are involved in _________________ signaling, last longer than signaling molecules involved in autocrine and paracrine signaling.

endocrine

Which type of cell communication involves a signal that is synthesized in one cell and has to travel a relatively long distance through the circulatory system to arrive at another (the target) cell?

endocrine

In GPCRs, the effector proteins activated by the G proteins are usually _____________.

enzymes

Intracellular receptors bind this type of ligand:

hydrophobic

Channel-linked receptors are proteins that allow the diffusion of _____________ across cellular membranes.

ions

On the following diagram, the molecule marked with "A" is which of the following? ligand effector receptor hormone

ligand

When a(n) ____________ binds to a channel-linked receptor, the channel opens and allows the flow of ions through the membrane.

ligand

_______________ - soluble ligands recognized by intracellular receptors stay in the blood longer than ___________________ - soluble signals.

lipid; water

Normally, calcium levels in the cytoplasm of cells would be which of the following relative to calcium levels in the ER or outside the cell.

lower

Small molecules or ions that relay signals inside the cytoplasm are called second ______________.

messengers

Small molecules or ions that relay signals inside the cytoplasm are called second _______________.

messengers

Steroid hormones typically act by which of the following?

modifying gene activity

Signaling molecules called ___________ are usually released from the ___________________ of nerve cells towards a closely located target cell.

neurotransmitters; tips

Which of the following are the two typical locations of intracellular receptors in the cell?

nucleus and cytoplasm

The 4 kinds of cell communication (between 2 different cells) based on distance from source to receptor are: direct contact, _____________________ signaling, ___________________ signaling, and _____________signaling.

paracrine; endocrine; synaptic

A protein activated by a kinase can be deactivated by a different type of enzyme called a ________________.

phosphatase

Which of the following would remove phosphate groups from a protein?

phosphatases

The addition or removal of phosphate groups allow cells to control __________________ function.

protein

In the case of hydrophilic signaling molecules, the molecule responsible for transferring the signaling information across the membrane is the _________________.

receptor

What effects do paracrine signals have?

short local effects

In cell communication, the conversion of the information conveyed by a signaling molecule into a cellular response is known as which of the following?

signal transduction

The primary function of ______________ hormone receptors is to regulate gene expression.

steroid

For a G protein to return to an inactive state, what event most occur?

the GTP (guanosine 5'-triphosphate) must be hydrolyzed to GDP (guanosine

Which of the following describes the response of skeletal muscle cells to an outflow of Ca^2+ from the ER?

the cells respond by contracting

What happens when a signaling molecule binds an enzymatic membrane receptor?

the receptor is activated

Intracellular receptors usually act by changing gene ____________ in the cell.

transcription

The process of signal ________________ is initiated when a ligand binds to a receptor protein.

transduction

True or false: some receptors can have several different subtypes or isoforms.

true