Cells Are The Smallest Unit Of Life

Question 1

Cell

Answer 1

Structural and functional unit of life

Question 2

Organismal functions depend on

Answer 2

Individual and collective cell functions

Question 3

3 Human cells

Answer 3

• Plasma membrane
• Cytoplasm
• Nucleus

Question 4

The basic functional unit of living organisms is the

Answer 4

Cell

Question 5

The three main components of all cells include the plasma membrane, the nucleus, and the

Answer 5

Cytoplasm

Question 6

Phospholipids orient themselves in aqueous solutions such that

Answer 6

The polar heads face the interior and exterior of the cell with the tails forming the center of the membrane

Question 7

Membrane protein:2 Types

Answer 7

1. Integral Proteins

2. Peripheral Proteins

Question 8

Integral Proteins

Answer 8

-Firmly inserted into membrane
(Most are transmembrane)

• Have hydrophobic and hydrophilic regions
• Function as transport Proteins(channel and carriers),enzymes,or receptors

Question 9

Peripheral Proteins

Answer 9

• Loosely attached to integral Proteins.
• Include filaments on intracellular surface for membrane support
• Functions as enzymes;motor proteins for shape change during cell division and muscle contraction;cell-to-cell connections

Question 10

Plasma Membrane

•Cells are surrounded by

Answer 10

Interstitial fluid (IF)

Question 11

Plasma membrane allows cell to:

Answer 11

• Obtain from (IF) exactly what it needs,exactly when it is needed
• Keep out what it does not need
• AKA “selectively” permeable membrane

Question 12

Membrane Transport

Answer 12

Plasma membranes selectively permeable

•Some molecules pass through easily; some do not

Question 13

Two ways substances cross membrane

Answer 13

1. Passive processes

2. Active Processes

Question 14

Types of membrane Transport

Answer 14

1. Passive processes

2. Active Processes

Question 15

Passive Processes

Answer 15

~No cellular energy (ATP)required

~Substance moves down its concentration gradient

Question 16

Active Processes

Answer 16

1. Energy (ATP)required

2. Occurs only in living cell membranes

Question 17

Passive Processes

Answer 17

•Diffusion

1. Simple diffusion
2. Carrier-mediated facilitates diffusion
3. Channel-mediated facilitated diffusion
4. Osmosis

Question 18

Molecule will passively diffuse through the cell membrane if:

Answer 18

1. It is lipid soluble,or
2. Small enough to pass through membrane channels,or
3. Assisted by carrier molecule

Question 19

Passive Processes Diffusion

Answer 19

•Collisions cause molecules to move down or with their concentration gradient
*Difference in concentration between two areas

Question 20

Speed influenced by molecule size

Answer 20

Smaller=Faster

Warmer=Faster

Question 21

Passive Processes: Facilitated Diffusion

Answer 21

Certain Lipophobic Molecules transported passively by
1.Binding to protein carriers
2.Moving through water-filled channels
(Don’t like Lipids)

Question 22

Carrier-Mediated Facilitated Diffusion

Answer 22

-Transmembrane integral Proteins are carriers.
-Transport specific polar molecules too large for channels
-Binding of substrate causes shape change in carrier the passage across membrane
-Limited by number of carriers present
•carriers saturated when all engaged

Question 23

Channel-Mediated Facilitated Diffusion…Two Types

Answer 23

1.Leakage Channels
•Always open
2.Gated Channels
•Controlled by chemical or electrical signals

Question 24

Carrier-Mediated Facilitated Diffusion

Answer 24

Via protein carrier specific for one chemical; binding of substrate causes transport protein to change shape

Question 25

Channel-Mediated Facilitated Diffusion

Answer 25

Through a channel protein;mostly ions selected on basis of size and charge

Question 26

Osmolarity

Answer 26

Measure of total concentration of solute particles

Question 27

Aquaporins

Answer 27

Through specific water channels

Question 28

Osmosis causes cells to

Answer 28

Swell and shrink

Question 29

Water moves by

Answer 29

Osmosis

Question 30

Tonicity

Answer 30

Ability of solution to alter cell’s water volume

Question 31

Isotonic

Answer 31

Solution with same non-penetrating solute concentration as cytosol

Question 32

Hypertonic

Answer 32

Solution with higher non-penetrating solute concentration than cytosol

Question 33

Hypotonic

Answer 33

Solution with lower non-penetrating solute concentration than cytosol

Question 34

Why don’t RBC’s lyse or shrink while in circulation ?

Answer 34

Because they are in a isotonic solution

Question 35

Where would steroid hormones most likely interact with their target cell

Answer 35

Inside the target cell’s cytoplasm or nucleus

Question 36

A red blood cell placed into a container of distilled water will

Answer 36

Gain water via osmosis

Question 37

Simple Diffusion

Answer 37

Gas exchange in our lungs A dissolving sugar cube Popcorn odor permeating the room