exam deck

Question 1

What is autocrine signaling?

Answer 1

Signaling where a cell responds to signals it produces itself.

Question 2

Describe paracrine signaling.

Answer 2

Signals act on nearby cells and are usually destroyed or taken up locally.

Question 3

How does endocrine signaling work?

Answer 3

Hormones travel through the bloodstream to reach distant target cells.

Question 4

What is neuronal signaling?

Answer 4

Fast, specific communication through neurotransmitters and neurohormones across synapses.

Question 5

Name four main types of cell surface receptors.

Answer 5

Ionotropic receptors, G protein-coupled receptors (GPCRs), receptor-enzymes, and integrin receptors.

Question 6

What is the primary role of intracellular receptors?

Answer 6

to regulate gene transcription directly in the nucleus.

Question 7

Which signaling pathway involves GPCRs activating adenylyl cyclase?

Answer 7

The cAMP pathway, where adenylyl cyclase converts ATP to cAMP, activating protein kinase A.

Question 8

Which second messengers are produced in the GPCR-phospholipase C pathway?

Answer 8

IP₃ and DAG, which release Ca²⁺ from internal stores and activate protein kinase C.

Question 9

What type of molecule typically binds to intracellular receptors?

Answer 9

Lipid-soluble molecules, such as steroid hormones, that can cross the plasma membrane.

Question 10

How does calcium function as a second messenger?

Answer 10

Calcium can activate proteins directly or bind to calmodulin, influencing processes like muscle contraction.

Question 11

What are the three main types of membrane transport?

Answer 11

Simple diffusion, facilitated diffusion, and active transport.

Question 12

Describe simple diffusion.

Answer 12

Movement of molecules from high to low concentration without energy usage (e.g., O₂ and CO₂).

Question 13

How does facilitated diffusion work?

Answer 13

Molecules move down their concentration gradient with help from a protein channel or carrier, without using energy.

Question 14

What is active transport?

Answer 14

Movement of molecules against their concentration gradient, using energy (e.g., Na⁺/K⁺ pump).

Question 15

How does the Na⁺/K⁺ pump function?

Answer 15

It transports 3 Na⁺ out and 2 K⁺ into the cell, using ATP, maintaining the cell’s ionic balance.

Question 16

What are ion channels, and what types are there?

Answer 16

Proteins that allow ions to pass through the membrane; they can be open (leak) channels or gated (voltage, ligand, or mechanically gated).

Question 17

What is the role of symport carriers?

Answer 17

To transport two substrates in the same direction across the membrane, like the SGLT transporter for Na⁺ and glucose.

Question 18

Define antiport carriers.

Answer 18

Carriers that transport substrates in opposite directions, like the Na⁺/K⁺ pump.

Question 19

Why is the electrochemical gradient important?

Answer 19

it drives the movement of ions across membranes, balancing concentration and electrical gradients.

Question 20

What is the resting membrane potential, and what influences it?

Answer 20

The negative charge inside a cell relative to the outside, mainly influenced by K⁺ permeability.

Question 21

How does the Na⁺/K⁺ pump contribute to cellular homeostasis?

Answer 21

It regulates cell volume, pH, and osmolarity by controlling ion distribution.

Question 22

What happens if the osmolarity inside a cell is too high?

Answer 22

Water influx can cause cell swelling or even lysis.

Question 23

Describe the role of the Na⁺/K⁺ ATPase in preventing osmotic imbalance.

Answer 23

By maintaining a low intracellular Na⁺ concentration, it prevents excessive water influx and cell swelling.

Question 24

How is intracellular pH regulated?

Answer 24

Through Na⁺/H⁺ exchange, Na⁺-HCO₃⁻ cotransport, and Cl⁻/HCO₃⁻ exchange.

Question 25

What are the three main functions of calcium regulation in cells?

Answer 25

Intracellular signaling, muscle contraction, and neurotransmitter release.