Bio Exam 2 Chap 4

Front 1

What is the plasma membrane and what does it do?

Back 1

Separated the internal environment of the cell from its external environment; regulates the entrance and exit of molecules in the cell

Front 2

The consistent internal environment of a cell is called ___.

Back 2

Homeostasis

Front 3

What molecule stiffens the phospholipid bilayer and controls fluidity?

Back 3

Cholesterol

Front 4

Which parts of the phospholipid bilayer are hydrophobic and which are hydrophilic?

Back 4

Polar heads, hydrophilic

Polar tails, hydrophobic

Front 5

What 2 types of proteins can a membrane have?

Back 5

Peripheral or integral

Front 6

What are peripheral proteins?

Back 6

Associated with only one part of the membrane

Front 7

What are integral proteins?

Back 7

Span the whole membrane

Front 8

What are glycolipids?

Back 8

Lipids attached to carbohydrates

Front 9

What are glycoproteins?

Back 9

Proteins attached to carbohydrates

Front 10

What are channel proteins and what is their nickname?

Back 10

Channels that allow solutes to pass through the membrane; "pores"

Front 11

What are carrier proteins and their nickname?

Back 11

Combine with a solute in order for it to pass through the membrane; "pumps"

Front 12

What are cell recognition proteins?

Back 12

Glycoproteins that help the body recognize when it is invaded by pathogens

Front 13

What are receptor proteins?

Back 13

Have a shape that allows specific molecules to bind causing the receptor to change shape and initiate a cellular response

Front 14

What do enzyme proteins do?

Back 14

Make chemical reactions go faster

Front 15

What does it mean to go "down" on a concentration gradient?

Back 15

From higher to lower concentration

Front 16

What does it mean to go "up" a concentration gradient?

Back 16

Going from lower to higher concentration. Requires input of energy

Front 17

What does selectively permeable mean?

Back 17

Blocks certain things and lets certain things pass

Front 18

Which molecules can freely cross the membrane and which can't depends on ___.

Back 18

Size

Polarity, charge

Front 19

What are examples of the small, noncharged molecules that can pass the membrane

Back 19

CO2, O2, glycerol, alcohol

Front 20

Can water pass through the plasma membrane? Why/why not

Back 20

NO; it is polar

Front 21

What are aquaporins?

Back 21

Special channels that allow water to cross the membrane

Front 22

What things CANNOT freely cross the membrane?

Back 22

Large molecules, ions, and charged molecules

Front 23

How can large molecules, ions, and charged molecules pass the membrane?

Back 23

Channel proteins

Carrier proteins

Vesicle formations

Front 24

What's a solution?

Back 24

Contains a solute and a solvent

Front 25

What is diffusion?

Back 25

The movement of molecules from a higher to a lower concentration

Front 26

When all molecules are spread evenly it's called ___.

Back 26

Equilibrium

Front 27

What kind of molecule can go straight through the lipid bilayer memebrane?

Back 27

Gasses; O2 and CO2

Front 28

What factors influence the rate of diffusion?

Back 28

Temperature (higher temp, quicker diffusion)

Pressure

Electrical currents

Size of molecule

Front 29

What is osmosis?

Back 29

Diffusion of water across a selectively permeable membrane

Front 30

What is osmotic pressure?

Back 30

The pressure that develops in a system due to osmosis

Front 31

What is an isotonic solution?

Back 31

The solute concentration is equal inside and outside the cell

Front 32

What is a hypotonic solution?

Back 32

There's more solute outside the cell than inside the cell

Front 33

What is a hypertonic solution?

Back 33

There's more solute inside the cell than outside

Front 34

What happens to an animal cell in an isotonic solution?

Back 34

There's no gain or loss of water and 0.9% salt in the blood

Front 35

What is cytolysis and hemolysis?

Back 35

Cell bursts; blood cell bursts

Front 36

What happens to an animal cell in a hypotonic solution?

Back 36

It gains water. Too much water. And bursts

Front 37

What does crenation mean?

Back 37

Shrivel

Front 38

What happens to an animal cell in a hypertonic solution?

Back 38

The cell loses water and shrivels

Front 39

What happens to a plant cell in an isotonic solution?

Back 39

No gain or loss of water

Front 40

What happens to a plant cell in a hypotonic solution?

Back 40

It gains water. Turgor pressure keeps it erect and the cell wall keeps it from bursting.

Front 41

What is plasmolysis?

Back 41

Cytoplasm shrinks

Front 42

What happens to a plant cell in a hypertonic solution?

Back 42

The cell loses water and shrivels. The plant dies

Front 43

What do carrier proteins combine with to transport across the membrane?

Back 43

Molecules or ions

Front 44

What 2 Linda's of transport do carrier proteins do?

Back 44

Facilitated transport

Active transport

Front 45

What is facilitated transport? Is ATP required?

Back 45

Molecules are transported down their concentration gradient; no

Front 46

What is active transport? Is ATP required?

Back 46

Molecules move up the concentration gradient; yes

Front 47

How are macromolecules transported in and out of the cell?

Back 47

Vesicle formation

Front 48

What's it called when a macromolecule exits a cell?

Back 48

Exocytosis

Front 49

What's it called when a macromolecule enters a cell?

Back 49

Endocytosis

Front 50

What are the 3 types of endocytosis?

Back 50

Phagocytosis

Pinocytosis

Receptor-mediated endocytosis

Front 51

What is phagocytosis?

Back 51

When cells take in large matter such as food molecules, viruses, or whole cells

Front 52

What is phagocytosis?

Back 52

When cells take in large matter such as food molecules, viruses, or whole cells (amoeba & macrophages)

Front 53

What is pinocytosis?

Back 53

When cells take in liquids and small particles dissolved in liquid (blood cells, plant root cells)

Front 54

What is receptor-mediated endocytosis?

Back 54

A type of pinocytosis that involves a coated pit (placental cells)