Chapter 5: Cell Structure

Question 1

____________ - Lipid bi-layer that acts like a barrier covering the entire cell surface.

Answer 1

Plasma membrane

Question 2

__________ - is the basic, living, structural and functional unit of the body.

Answer 2

cell

Question 3

What are the three main parts of the cells?

Answer 3

1. plasma membrane
2. cytoplasm
3. nucleus

Question 4

___________ - forms the cell’s flexible outer surface,
separating the cell’s internal environment from the external environment . It is a selective barrier that regulates the flow of materials into and out of a cell.

Answer 4

plasma membrane

Question 5

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

Answer 5

cytoplasm

Question 6

What are the two components of cytoplasm?

Answer 6

1. cytosol
2. organelles

Question 7

________ - the fluid portion of cytoplasm, contains water, dissolved solutes, and suspended particles.

Answer 7

Cytosol

Question 8

_________ - is a large organelle that houses most of a cell’s DNA.

Answer 8

nucleus

Question 9

_________ - a single molecule of DNA associated with several proteins, contains thousands of hereditary units called genes that control most aspects of cellular structure and function.

Answer 9

chromosome

Question 10

What is the basic structural framework of the plasma membrane?

Answer 10

lipid bilayer

Question 11

What are the three types of lipid molecules that made up the bilipid layer?

Answer 11

1. phospholipids
2. cholesterol
3. glycolipids

Question 12

_________ - are the major membrane lipids with a polar head (which have high affinity for water i.e. hydrophilic) and two non-polar tails which are lipophilic.

Answer 12

Phospholipids

Question 13

What is the component of plasma membrane that plays a role in fluidity of plasma membrane?

Answer 13

cholesterol

Question 14

____________ - are classified as integral or peripheral according to whether they are firmly embedded in the membrane.

Answer 14

Membrane proteins

Question 15

__________ - proteins that extend into or through the lipid bilayer among the fatty acid tails and are firmly embedded in it.

Answer 15

Integral proteins

Question 16

_________ - 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.

Answer 16

peripheral proteins

Question 17

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

Answer 17

glycocalyx

Question 18

Carriers are also known as:

Answer 18

transporters

Question 19

What are the Integral proteins that serve as cellular recognition sites?

Answer 19

receptors

Question 20

A specific molecule that binds to a receptor is called a _________ of that receptor.

Answer 20

ligand

Question 21

Many cells in the body do need to communicate amongst themselves. This is accomplished by narrow, gate-like spaces between the two cells called:

Answer 21

Membrane Junction

Question 22

What are the 3 types of junctions?

Answer 22

1. Desmosomes
2. Gap junctions
3. Tight junctions

Question 23

____________ - consists of several proteins located at opposing plasma membranes. Common junctions in those cells which undergo forces that may change, shape of cell (temporarily) i.e. mechanical forces or pressure on skin cells.

Answer 23

Desmosomes

Question 24

___________ - are groups of proteins that form channels .

Answer 24

Gap junctions

Question 25

Example of cell that passes through the Gap junctions.

Answer 25

1. Brain cells 2. Heart cells 3. Smooth muscle cells

Question 26

\_\_\_\_\_\_\_\_\_\_\_ - exist in cells which have their extracellular surfaces of their plasma membranes directly attached. Allow exchange of virtually no molecule.

Answer 26

Tight junctions