Transport and water potential quiz

Mrs. Bose AP Bio

Types of Transport

Passive Transport
Active Transport

Passive Transport

No energy needed
Particle movement from higher to lower concentration

Active Transport

Requires energy (ATP)
Particle movement from lower to higher concentration

Endocytosis

A form of Active Transport where a cell takes in material by forming a vacuole around it

Types of Endocytosis

Phagocytosis
Pinocytosis
Receptor-Mediated Endocytosis

Phagocytosis

The cell membrane forms around another substance, “cell eating”

Pinocytosis

Cell takes in liquids surrounding it. Non specific

Receptor-Mediated Endocytosis

Transports a specific molecule into the cell using vesicles, like cholesterol

Facilitated Diffusion

A form of passive transport that uses transport proteins
helps hydrophilic substances cross; no energy used

Types of Facilitated Diffusion

Carrier Proteins
Channel Proteins

Carrier Proteins

Loosely bind/carry specific larger molecule across (ex. glucose)

Channel Proteins

Provide hydrophilic channel/opening for ions and water to diffuse
Can be Gated

Simple Diffusion

no proteins or energy involved
Movement across the lipid bilayer
used for small or hydrophobic molecules

Osmosis

Form of Passive Transport, sometimes needs protein help (aquaporin)

movement of water from areas of more free water to areas of less free water

Aquaporin

channel protein that allows passage of water

Cell Membrane Pumps

carrier proteins that transport small + charged substances against concentration gradient (low to high)

Types of Cell Membrane Pumps

Na+/K+ pump
Proton (H+) Pump

Na+/K+ pump

Pumps 3 Na+ out, 2 K+ into cell, makes cell interior more negative
Process powered by ATP

Proton (H+) Pump

Pushes protons across membrane
ex) mitochondria for ATP production
Stores energy to be used later via charge differences

Bulk Transport

Transport of large molecules
Independent of concentration gradient
Energy is required
ex) endocytosis and exocytosis

Exocytosis

When a vacuole membrane becomes a part of the cell membrane and the contents are released, Active Transport
ex) Proteins, hormones, neurotransmitters, waste

Diffusion

when energy is required to move materials through a cell membrane

Equilibrium

When the molecules of one substance are spread evenly throughout another substance to become balanced

Hypotonic Solution

Less concentrated solution
More free water

Hypertonic Solution

More concentration
Less free water

Isotonic Solution

2 solutions have equal concentrations

How does water move?

hypotonic to hypertonic

Plasmolysis

plant cell shrinking due to water loss

Crenation

animal cell shrinking due to water loss

Turgor pressure

The force of water in the vacuole pressing against the cell wall, expands only until back pressure is exerted that limits further water intake
Keeps the cell healthy.

Cytolysis

animal cell bursting due to water gain

Cells in hypertonic solutions…

Lose water, get smaller

Cells in hypotonic solutions…

Gain water, get bigger