Chapter 1 - Cells In Action

Question 1

A cell structure surrounding the cell

Answer 1

Cell membrance

Question 2

Components of plasma membrane

Answer 2

• glycerol and phosphate
• fatty acid
• phospholipids

Question 3

Hydrophilic

Answer 3

Attracted to water/water-loving

Question 4

Hydrophobic

Answer 4

repelled to water/water-fearing

Question 5

The membrane exhibits properties that resemble a fluid in which lipids and proteins can move relative to each other within the membrane

Answer 5

Fluid Mosaic

Question 6

Transmit messages to the cell’s interior

Answer 6

Receptors

Question 7

Proteins that create tunnels which selectively allow certain substances to enter and exit the cell

Answer 7

Transport Proteins

Question 8

Functions of plasma membrane

Answer 8

• separates cell contents from environment
• prevents materials from passing through
• facilitates entrance and exit of materials

Question 9

Three important characteristics of a molecule that affect their ability to cross the cell membrane

Answer 9

• size
• charge
• solubility

Question 10

The difference between the amount of molecules present at two regions which determines the movement of the molecules

Answer 10

Concentration Gradient

Question 11

Molecules move along the concentration gradient that is from high to low

Answer 11

Passive Transport

Question 12

Molecules move against the concentration gradient that is from low to high

Answer 12

Active Transport

Question 13

This is required for active transport to occur

Answer 13

Energy

Question 14

Cell eating

Answer 14

Phagocytosis

Question 15

Cell drinking

Answer 15

Pinocytosis

Question 16

This phenomenon is a natural process where molecules from the air move from a point of greater concentration to a point of lesser concentration to attain equilibrium

Answer 16

Diffusion

Question 17

This condition of continuous movement where there is no overall change in concentration is known as

Answer 17

Dynamic Equilibrium

Question 18

Cell membrane is also called as _______________________ because it allows certain molecules to enter but also hinders the passage of other molecules

Answer 18

Semipermeable Membrane

Question 19

Water molecules also move from a point of higher concentration to a point of lower concentration across the cell membrane. This movement of water is a specific type of diffusion called

Answer 19

Osmosis

Question 20

______ is the main compound inside a cytoplasm

Answer 20

Water

Question 21

Movement of water molecules as they undergo osmosis

Answer 21

Water Potential

Question 22

The force that moves water molecules through a semipermeable membrane

Answer 22

Osmotic Pressure

Question 23

The strength of a solution in relation to osmosis

Answer 23

Tonicity

Question 24

A solution with the same concentration of water and other solutes as its cytoplasm

Answer 24

Isotonic Solution

Question 25

A solution with more water outside the cell than inside its cytoplasm

Answer 25

Hypotonic Solution

Question 26

The pressure exerted by the water molecule is referred to as

Answer 26

Turgor Pressure

Question 27

A solution that causes cells to shrink and lose their shape as a result of water loss

Answer 27

Hypertonic Solution

Question 28

When RBCs are placed in a hypertonic solution, cells undergo a process called

Answer 28

Crenation

Question 29

Movement of molecules across the cell membrane with the help of membrane transport proteins

Answer 29

Facilitated Diffusion

Question 30

Properties of Facilitated Diffusion

Answer 30

• Concentration gradient is required because it cannot transport molecules from low to high concentration
• Energy is not needed
• Transport proteins are specific to the type of molecules they can transport across the membrane
• The rate of transport reaches a maximum when all membrane transport proteins are used up
• Membrane transport proteins are sensitive to inhibitors that can cause them not to function

Question 31

Two types of membrane transport proteins involved in facilitated diffusion

Answer 31

Channel proteins and Carrier proteins

Question 32

This type of protein undergo temporary binding to the molecule, resulting in a conformational change that moves the molecule through the membrane

Answer 32

Carrier proteins

Question 33

This protein contain tunnels or openings that serve as passageways of molecules

Answer 33

Channel proteins

Question 34

______ and ______ use carrier proteins to cross the cell membrane

Answer 34

Amino acids and glucose

Question 35

He discovered water protein channels called aquaporins that allow water molecules to rapidly diffuse into and out of the cells found in areas with high water influx

Answer 35

Peter Agre

Question 36

Properties of Active Transport

Answer 36

• Energy is needed in the form of ATP
• Transport proteins are highly specific to the type of molecules they can transport across the membrane
• The rate of transport reaches to a maximum when all membrane transport proteins are being used
• Membrane transport proteins are sensitive to inhibitors that can cause them not to function

Question 37

Large molecules enters the cell by a process called

Answer 37

Endocytosis

Question 38

The plasma membrane becomes indented and forms a pit. The pit lined with receptor proteins picks specific molecules from the surroundings. The pit then closes and pinches off to form a vesicle, which eventually carries the molecules inside the cytoplasm. This process is called

Answer 38

Receptor-Mediated endocytosis

Question 39

Materials for export, like proteins produced in the ribosomes and packaged in the Golgi apparatus, are secreted out of the cell by

Answer 39

Exocytosis