Cell

Question 1

What are the mechanisms of intercellular communication?

Answer 1

Direct communication, Paracrine communication, Endocrine communication, Synaptic communication.

Question 2

How does direct communication occur?

Answer 2

Through gap junctions.

Question 3

How does paracrine communication occur?

Answer 3

Through extra-cellular fluid.

Question 4

How does endocrine communication occur?

Answer 4

Through the blood stream.

Question 5

How does synaptic communication occur?

Answer 5

Across synaptic cleft.

Question 6

What are the chemical mediators in direct communication?

Answer 6

Ions, small solutes, lipid soluble material.

Question 7

What are the chemical mediators in paracrine communication?

Answer 7

Paracrine factors.

Question 8

What are the chemical mediators in endocrine communication?

Answer 8

Hormones.

Question 9

What are the chemical mediators in synaptic communication?

Answer 9

Neurotransmitters.

Question 10

What is the effect of direct communication?

Answer 10

Usually limited to adjacent cells of the same type.

Question 11

What is the effect of paracrine communication?

Answer 11

Limited to local area. Target cell should have receptors.

Question 12

What is the effect of endocrine communication?

Answer 12

Target cells are in other tissues and organs.

Question 13

What is the effect of synaptic communication?

Answer 13

Limited to very specific area. Target cells must have appropriate receptors.

Question 14

What are the characteristics of the plasma membrane?

Answer 14

Semi permeable, creates specialized compartments.

Question 15

What does the plasma membrane contain?

Answer 15

Cell adhesion/junction molecules, cell surface proteins, cell surface receptors, cell recognition molecules, channels, transport proteins.

Question 16

What is the role of endocytosis and exocytosis?

Answer 16

Involves the membrane.

Question 17

What is endocytosis?

Answer 17

Endocytosis of LDL.

Question 18

What is exocytosis?

Answer 18

Insulin secretion from the pancreatic beta cell.

Question 19

What is the significance of organelles communicating chemically?

Answer 19

They cooperate and share resources.

Question 20

What is the medium required for biochemical reactions in cells?

Answer 20

Water-based cytoplasm.

Question 21

What are the types of macromolecules mentioned?

Answer 21

Lipids, proteins, carbohydrates, nucleic acids.

Question 22

What are the functions of mitochondria?

Answer 22

TCA cycle, aerobic respiration, regulation of cellular metabolism.

Question 23

What is the role of the nucleus?

Answer 23

Serves as the information center and stores genetic material.

Question 24

What do ribosomes do?

Answer 24

Catalyze peptide bond formation during protein synthesis.

Question 25

What is the endomembrane system?

Answer 25

A system of related membranes including the cell membrane, nuclear membrane, endoplasmic reticulum, Golgi apparatus, vesicles, and vacuoles.

Question 26

What are the functions of the Golgi apparatus?

Answer 26

Receives, modifies, stores, and secretes proteins and lipids.

Question 27

What are lysosomes?

Answer 27

The waste disposal system of the cell.

Question 28

What are lysosomal storage diseases?

Answer 28

Inborn errors of metabolism characterized by the accumulation of substrates in excess due to defective functioning of lysosomes.

Question 29

What are the functions of peroxisomes?

Answer 29

Breaking down fatty acids, removing excess hydrogen peroxide, and participating in the synthesis of cholesterol and bile acids.

Question 30

What is the role of the cytoskeleton?

Answer 30

Provides structural support for the cell and facilitates intracellular movement.

Question 31

What is the extracellular matrix?

Answer 31

A three-dimensional meshwork of secreted macromolecules that fills the space between cells.

Question 32

What are exosomes?

Answer 32

Tiny, membrane-enclosed molecules derived from eukaryotic cells, involved in tumorigenesis and potential biomarkers.