Chapter 3

Question 1

What is a cell? How is it measured?

Answer 1

The cell is a basic unit of structure and function in the body. Cells are measured in micrometers.

Question 2

What is a differentiated cell?

Answer 2

A cell with a specialized characteristic.

Question 3

Are all cells the same?

Answer 3

False, cells vary in size and shape: as well as structure and function are inter-related.

Question 4

What is a composite cell?

Answer 4

A cell that shows the components found in most cells; that contain The 3 Major Parts of a cell.

Question 5

What are the 3 three major parts of a cell?

Answer 5

Nucleus, Cytoplasm, Cell membrane

Question 6

What does the Nucleus consist of?

Answer 6

It contains genetic material and directs cells activities

Question 7

What is the cytoplasm ?

Answer 7

It consists of organelles, with special functions, suspended in a liquid called Cytosol

Question 8

What is the Cell Membrane? What does it do?

Answer 8

• outer boundary of the cell
• maintains integrity of cell
• separates intracellular fluid (cytosol) from extracellular fluid
•signal transduction: permits cell to receive and respond to messages
•consists mainly of lipids and proteins, with some carbohydrates

Question 9

What is selectively permeable?

Answer 9

The cell membrane regulates entry and exit of substances

Question 10

What is a phospholipid bilayer?

Answer 10

It is the cell membrane framework
• water soluble (hydrophilic) heads form surfaces
• water-insoluble (hydrophobic) tails form interior
•bilayer is permeable to lipid-soluble substances not to water soluble substances

Question 11

What does Cholesterol do for the cell membrane?

Answer 11

It stabilizes the membrane, and helps keep it impermeable to water soluble substances

Question 12

What is cytoplasm?

Answer 12

•It consists of networks of membranes and organelles suspended in cytosol
•contains the cytoskeleton: A supporting framework of proteins rods and tubules

Question 13

What is Ribosome?

Answer 13

• it’s composed of protein and RNA
• located free in the cytoplasm or on RER
•provides structural support and enzyme activity to link amino acids in protein synthesis

Question 14

What is Endoplasmic Reticulum? ER

Answer 14

• it’s membrane bound sacs, canals, vesicles
• tubular transport system
• Rough and Smooth ER

Question 15

What is Rough ER?

Answer 15

It contains ribosomes &
Conducts protein synthesis

Question 16

What is smooth ER?

Answer 16

It does not have ribosomes &
Conducts lipids synthesis

Question 17

What are vesicles?

Answer 17

Membranous sacs that store or transport substances.

Question 18

What is Golgi Apparatus?

Answer 18

Sacs of flattened, membranous sacs.
Refines, packages, and delivers proteins made on the RER

Question 19

What is Mitochondria?

Answer 19

•A membrane bound, fluid filled sac
• house chemical reactions that extract energy from nutrients
( cellular respiration that produces ATP)
“ THE POWERHOUSE “ of the cell

Question 20

What is Lysosomes?

Answer 20

• Small membranous sacs
•contain enzymes that digest proteins, carbohydrates, nucleic acids, bacteria, debris, worn out cell parts
“GARBAGE DISPOSAL” of cell

Question 21

What are Peroxisomes?

Answer 21

A membranous sacs similar to lysosomes, that contain enzymes that digest lipids, alcohol, hydrogen peroxide

Question 22

What is tonicity?

Answer 22

The ability of a solution outside the cell to alter water volume inside cell

Question 23

What is Isotonic solution?

Answer 23

Same osmotic pressure; cells in an isotonic solution have no net gain or loss of water

Question 24

What is a Hypertonic Solution?

Answer 24

Higher osmotic pressure, cells lose water

Question 25

What is Hypotonic solution?

Answer 25

Lower osmotic pressure, cells gain water

Question 26

What is active transport?

Answer 26

Movement of substances across a membrane from region of lower concentration to region of higher concentration
• uses carrier molecules in cell membrane, called pumps
•active process requires ATP energy

Question 27

What is passive transport?

Answer 27

Does not require cellular energy (ATP)
Such as Diffusion, osmosis, facilitated diffusion, filtration

Question 28

What is diffusion? When does it occur?

Answer 28

1.Movement of atoms, molecules or ions from region of higher concentration to lower concentration
2. It occurs only with oxygen, carbon dioxide and other lipids substances since they are permeable to the cell membrane

Question 29

What is filtration?

Answer 29

•Process that forces molecules through membranes by exerting pressure
•used to separate solids from water, or small particles from larger ones.
•passive process no ATP required

Question 30

Active mechanisms:

Answer 30

Require ATP to move substances across cell membrane

Active transport, endocytosis, exocytosis, transcytosis

Question 31

Active transport

Answer 31

Active process, requires ATP

Uses carrier molecules in cell membrane, called pumps

Movement of substances across a membrane from region of lower concentration to region of higher concentration