3.1 and 3.2

Question 1

What are cells?

Answer 1

Cells are the basic, living, structural, and functional units of the body.

Question 2

What is cell biology?

Answer 2

The scientific study of cells

Question 3

What are the three principal parts of a cell?

Answer 3

Plasma membrane, cytoplasm, nucleus

Question 4

What is plasma membrane?

Answer 4

• forms the cell’s flexible outer surface, separating the cell’s internal environment (everything inside the cell) from the external environment (everything outside the cell).
• selective barrier that regulates the flow of materials into and out of a cell.
• plays a key role in communication among cells and between cells and their external environment

Question 5

What is cytoplasm?

Answer 5

-consists of all the cellular contents between the plasma membrane and the nucleus.

Question 6

What are the two compartment of cytoplasm?

Answer 6

cytosol and organelles

Question 7

What is cytosol?

Answer 7

the fluid portion of cytoplasm, also called intracellular fluid, contains water, dissolved solutes, and suspended particles.

Question 8

What is nucleus?

Answer 8

a large organelle that houses most of the cell’s DNA. Within the nucleus, each chromosome contains thousands of hereditary units called genes that control most aspects of cellular structure and function

Question 9

What phrase is best described for plasma membrane?

Answer 9

fluid mosaic model

Question 10

What is lipid bilayer?

Answer 10

The basic structural framework of the plasma membrane is the lipid bilayer

Question 11

What are three types of lipid molecules?

Answer 11

phospholipids, cholesterol, and glycolipids

Question 12

What are phospholipids?

Answer 12

About 75% of the membrane lipids are phospholipids, lipids that contain phosphorus.

Question 13

What are cholesterol?

Answer 13

Present in smaller amounts are cholesterol (about 20%), a steroid with an attached-OH (hydroxyl) group

Question 14

What are glycolipids?

Answer 14

(about 5%), lipids with attached carbohydrate groups

Question 15

What is amphipathic?

Answer 15

the bilayer arrangement occurs because the lipids are amphipathic molecules, which means that they have both polar and non polar parts.

Question 16

What region of cholesterol is polar?

Answer 16

The OH group

Question 17

What region of cholesterol is non polar?

Answer 17

the stiff steroid rings and hydrocarbon tail of cholesterol

Question 18

What are integral proteins?

Answer 18

Integral proteins extend into or through the lipid bilayer and are firmly embedded in it.

Question 19

What are transmembrane proteins?

Answer 19

Most integral proteins are transmembrane proteins, which means that they span the entire lipid bilayer and protrude into both the cytosol and extracellular fluid.

Question 20

What are peripheral proteins?

Answer 20

Peripheral proteins are not as firmly embedded in the membrane. They are attached to the polar heads of membrane lipids or to integral proteins at the inner or outer surface of the membrane.

Question 21

What are glycoproteins?

Answer 21

Many integral proteins are glycoproteins, proteins with carbohydrate groups attached to the ends that protrude into the extracellular fluid.

Question 22

What is glycocalyx?

Answer 22

The carbohydrate portions of glycolipids and glycoproteins form an extensive sugary coat

Question 23

what are Ion channels?

Answer 23

pores or holes that specific ions, such s K+, can flow through to get into or out of the cell. Most ion channels are selective: they allow only a single type of ion to pass through

Question 24

What are carriers?

Answer 24

selectively moving a polar substance or ion from one side of the membrane tot he other. Carriers also known as transporters.

Question 25

What are receptors?

Answer 25

serves as cellular recognition sites. Each type of receptor recognizes and binds a specific type of molecule. For instance, insulin receptors bind the hormone insulin.

Question 26

What are ligand?

Answer 26

A specific molecule that binds to a receptor.

Question 27

What are enzymes?

Answer 27

catalyzes specific chemical reactions at the inside or outside surface of the cell

Question 28

What are linkers?

Answer 28

actors proteins in the plasma membranes of neighbouring cells to one another or to protein filaments inside and outside the cell. Peripheral proteins also serve as enzymes and linkers.

Question 29

What are cell-identify markers?

Answer 29

Membrane glycoproteins and glycolipids often serve as cell-identify markers. They may enable a cell to (1) recognize other cells of the same kind during tissue formation or (2) recognize and respond to potentially dangerous foreign cells. The ABO blood type markers are one example of cell-identify markers.