chapter 3: Cellular level of Organization

Question 1

What is the basic function of the cell membrane?

Answer 1

The cell membrane acts as a protective barrier that controls what enters and what exists the cell.

Question 2

What is the basic function of the nucleus?

Answer 2

Nucleus is the control center of the cell and stores DNA and coordinates activities.

Question 3

What is the basic function of the cytoplasm?

Answer 3

Gel like substance inside the cell between the cell membrane and the nucleus. It supports and suspends organelles and facilitate movements of materials within the cell.

Question 4

There are three basic components of cells:

Answer 4

1. Cell (plasma) Membrane
2. Nucleus
3. Cytoplasm

Question 5

What is an organelle?

Answer 5

A tiny part inside a cell that has a special job

Question 6

Extracellular (interstitial) is located ?

Answer 6

Outside the cell (Na+)

Question 7

Interstitial fluid is located ?

Answer 7

Inside the cell (K+)

Question 9

Is the composition the same?

Answer 9

No, intracellular is thicker because it contains high concentrations of proteins, enzymes, organelles, and more potassium, phosphate, magnesium.

Question 10

What is interstitial fluid? Is it a component of ICF or ECF?

Answer 10

ECF, ECF includes interstitial which is the fluid that surrounds and bathes cells in tissues.

Question 11

List three functions of the membrane.

Answer 11

1. Semi permeable barrier
2. Protection/structure
3. Cell communication (contains protein receptors)

Question 13

Phospholipid bilayer: remember, a phospholipid is unique because it has a head that is ______ and two “tails” that are _____.

Answer 13

Hydrophilic and hydrophobic

Question 14

How does Integral (intrinsic) and peripheral (extrinsic) proteins differ?

Answer 14

Integral proteins goes through the cell membrane and cannot be removed while peripheral can since they are only on one side of the cell.

Question 15

What are four functions of proteins in the cell membrane?

Answer 15

1. Transport
2. Receptor
3. Enzyme activity
4. Cell recognition

Question 16

Cholesterol: What type of organic compound is cholesterol?

Answer 16

Lipid (fat)

Question 17

What is the function of cholesterol in the cell membrane?

Answer 17

Creates rigidity and structure to the cell membrane

Question 18

Why are glycolipids and glycoproteins significant in the cell membrane?

Answer 18

They aid cell recognition, communication, protection, and stabilize membrane.

Question 19

What are microvilli?

Answer 19

Tiny finger like projections on surface of some cells to increase surface area to enhance absorption and secretion.

Question 20

What type of cell would have a lot of microvilli and why would it need to have these structures?

Answer 20

Epithelial cells in the small intestine have a lot of microvilli because they need a large surface area to absorb nutrients from digested food.

Question 21

What are three types of cell junctions?

Answer 21

1. Tight Junctions
2. Gap Junctions
3. Desmosomes

Question 22

What is the purpose of tight junction and where is found?

Answer 22

Purpose: Seal Cells tightly together to prevent leakage of substance between the,

Found: Epithelial tissues lining intestines, kidneys, blood brain barrier

Question 23

What is the purpose of desmosome and where is found?

Answer 23

Purpose: Helps tissues resists stretching and tearing

Found: Skin, Heart, Uterus

Question 24

What is the purpose of Gap Junctions and where is found?

Answer 24

Purpose: Allows direct communication between cells by letting small ions and small molecules pass through

Found:Cardiac muscle, smooth muscle, neural tissue