Chapter 9.1-9.3

Order the steps in cell signaling as they occur in a cell. Start with the first step at the top.

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

A molecule to which a signal ligand binds is called which of the following?

A receptor protein

What does the binding of a ligand to its receptor stimulate?

A signal transduction pathway

When a signal molecule binds to an enzymatic receptor, it usually ______ it.

Activates

In ______ signaling, a cell sends a signal to itself, by secreting molecules that bind to receptors in its own plasma membrane.

Autocrine

Some cells send signals to themselves by secreting molecules that bind to receptors in their own plasma membrane. What is this known as?

Autocrine signaling

Steroid hormone receptors are usually inactive when the hormone that they bond is not present. Why?

Because the DNA-binding domain is blocked by an inhibitor protein

Why can steroid hormones cross the membrane and bind to intracellular receptors?

Because they are non-polar

Which of the following statements best describes the process of cell communication?

Cell communication includes interaction between signal and receptor, signal transduction, and a cellular response.

Membrane receptors typically belong to one of three subclasses: _____-linked receptors, ________ receptors and G-________ coupled receptors.

Channel Enzymatic or enzyme Protein

What types of receptor proteins allow the diffuision of ions across cellular membranes?

Channel-linked receptors

Sample of steroids include which of the following?

Cortisol Estrogen Testosterone

Intracellular receptors are usually located in the ______ or in the ________.

Cytoplasm Nucleus

Prior to binding the hormone, steroid hormone receptors are located in the _____, however, their primary site of action is in the _____

Cytoplasm Nucleus

Each steroid receptor has three functional domains— 1. a hormone-binding domain 2. A _______-binding domain 3. a domain that can interact with co-activators to affect the level of gene _________.

DNA Transcription or expression

In _____ contact, 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

The type of cell communication characterized by the interaction of a signal molecule in the plasma membrane of one cell and a receptor protein in the plasma membrane of an adjacent cell is called which of the following?

Direct contact

Choose the four general types of cell communication.

Direct contact Paracrine Signaling Endocrine Signaling Synaptic Signaling

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

The four kinds of cell communication (between two different cells) based on the distance from source to receptor are: direct contact, ________ signaling, _________ signaling, and _________ signaling.

Endocrine Paracrine Synaptic

What type of cellular communication us depicted on this diagram?

Endocrine signaling

Which signaling process occurs when cells release signals that travel long distances to affect target cells?

Endocrine signaling

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

Enzymatic receptors Channel-linked receptors G protein-coupled receptors

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

Expression or transcription

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

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

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

Which of the following statements that compare endocrine, paracrine, and autocrine signaling is true?

Hormones are longer lived than paracrine or autocrine signals.

Cell surface or membrane receptors bind this type of ligand.

Hydrophilic

Intracellular receptors bind this type of ligand.

Hydrophobic

When a steroid hormone binds the hormone-binding domain of a steroid hormone receptor, the receptors's conformation changes. As a result of this, the ______ proteins is released, which exposes the ______-binding site of the receptor.

Inhibitor DNA

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

Ions

A signaling molecule is known as which of the following?

Ligand

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

Ligand, neurotransmitter, or chemical

Which of the following persists longest?

Lipid soluble hormones

In endocrine signaling, cells release signals that travel in which of the following ways?

Long distance to many target cells

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

Messengers

A process in which one molecule fits specifically based on its complementary shape with another molecule is called which of the following?

Molecular recognition

The receptor for the small gas molecule _____ _____ is an intracellular receptor that acts as an enzyme.

Nitric or N Oxide or O

In what type of signaling do secretions from one cell have an effect only on the cells in the neighboring area?

Paracrine

The diagram depicts which type of signaling?

Paracrine signaling

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

Phosphatase

The class of enzyme that removes phosphate groups, thus reversing the action of kinases, is which of the following?

Phosphatases

The addition or removal of which group is a major source of control for protein during signal transduction?

Phosphate

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

Proteins or enzymes

The intersection of a receptor with its ligand is an example of molecular _________.

Recognition

Which is the effect of the intracellular messenger cGMP on muscle cells?

Relaxation of smooth muscle cells

Most cytoplasmic proteins kinases fall in the category of which of the following?

Serine/threonine kinases

Paracrine signals typically have _______-lived, _____ effects.

Short Local

What effects do paracrine signals have?

Short, local effects

Different cells can responds to the same signaling molecule in a completely (sometimes opposite) different way because they can have different ______ ______ pathways associated with the signaling molecule.

Signal transduction

Which of the following are examples of paracrine signaling?

Signals between immune cells. Signals that coordinate the activities of clusters of cells during development

Estrogen, cortisol, and progesterone are examples of which of the following?

Steriods

The type of cell communication characterized by the transmission of a signal molecule across a small gap to a single target cell is which of the following?

Synaptic

On the following diagram, the molecule marked with the letter A is which of the following?

The ligand

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

The nucleus The cytoplasm

The molecule marked with the letter B is which of the following?

The receptor

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

The receptor is activated

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.

A signal _______________ pathway is initiated when a ligand binds to a receptor protein.

Transduction

T or F: Protein kinases add phosphate groups from ATP to proteins.

True

Which of the following statements regarding signal transduction pathways (abbreviated SDP below) 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.

Choose the two types of protein kinases based on the amino acid to which a phosphate groups is added.

Tyrosine kinases Serine/threonine kinases

Where do second messengers relay signals?

inside the cell

What term is used to describe a signaling molecule?

ligand

What happens when a signaling molecule binds to a channel-linked receptor?

the channel opens and allows the flow of ions through the membrane