Homeostasis & Transport. Section 1: Diffusion & Osmosis.

Homeostasis & Transport

Homeostasis & Transport

Section 1: Diffusion & Osmosis

Section 1: Diffusion & Osmosis

HomeostasisHomeostasis

Homeostasis: the biological balance between a cell or an organism and its environment Cells maintain

homeostasis by controlling and regulating what gets into and out of the cell.

Homeostasis: the biological balance between a cell or an organism and its environment Cells maintain

homeostasis by controlling and regulating what gets into and out of the cell.

Passive TransportPassive Transport

Passive Transport: the movement of any substance across a cell membrane without the use of cell energy Diffusion Osmosis Facilitated Diffusion Gated Channel

Passive Transport: the movement of any substance across a cell membrane without the use of cell energy Diffusion Osmosis Facilitated Diffusion Gated Channel

DiffusionDiffusion

Diffusion: the process by which molecules move from an area of greater concentration to an area of lower concentration

Diffusion: the process by which molecules move from an area of greater concentration to an area of lower concentration

Diffusion

Diffusion

Brownian

Motion

Brownian

Motion

Brownian Motion: molecules are in a constant state of random motion

Brownian Motion: molecules are in a constant state of random motion

BrownianMotion

BrownianMotion

Concentration GradientConcentration Gradient

Concentration Gradient: the difference in concentration of a substance across a space

Concentration Gradient: the difference in concentration of a substance across a space

Dynamic EquilibriumDynamic Equilibrium

Dynamic Equilibrium: a state that exists when the concentration of a substance is the same throughout a space

Dynamic Equilibrium: a state that exists when the concentration of a substance is the same throughout a space

Dynamic EquilibriumDynamic

Equilibrium

Review of Cell Membrane Structure


Diffusion Across Membranes

Diffusion Across Membranes

Not all molecules can diffuse through all membranes.

The ability of a molecule to pass through a membrane depends on the size and type of molecule and the molecular structure of the membrane.

Not all molecules can diffuse through all membranes.

The ability of a molecule to pass through a membrane depends on the size and type of molecule and the molecular structure of the membrane.

Small nonpolar molecules can diffuse through the cell membrane

OsmosisOsmosis

Osmosis: the diffusion of water molecules through a selectively permeable membrane from an area of high water concentration to an area of lower water concentration

Osmosis: the diffusion of water molecules through a selectively permeable membrane from an area of high water concentration to an area of lower water concentration

OsmosisOsmosis

Three Types of SolutionsThree Types of Solutions

90% H2O10% solute

90% H2O10% solute

90% H2O10% solute

90% H2O10% solute

85% H2O15% solute

95% H2O5% solute

Isotonic(no net movement

of water)

Hypotonic Hypertonic


Plant Cells


Animal Cells

Three Types of SolutionsThree Types of SolutionsHypotonic solution

(a) Animal cell

(b) Plant cell

H2O

Cytolysis

H2O

Turgid (normal)

H2O

H2O

H2O

H2O

Normal

Isotonic solution

Flaccid

H2O

H2O

Shriveled

Plasmolysis

Hypertonic solution

Contractile VacuolesContractile Vacuoles

Contractile Vacuole: an organelle in microorganisms that excretes water collect excess water → contract →

squeeze out water

Contractile Vacuole: an organelle in microorganisms that excretes water collect excess water → contract →

squeeze out water

Study the diagram below. It represents a container that is divided by a semipermeable membrane. A different solution in its initial

state is shown on each side of the membrane.

Study the diagram below. It represents a container that is divided by a semipermeable membrane. A different solution in its initial

state is shown on each side of the membrane.

1. Describe which molecule(s) will move through the membrane and which molecule(s) will not.2. Describe the relative rates at which the molecule(s) will

move across the membrane.3. Describe in which direction the molecule(s) will move.4. Describe how long the molecule(s) will continue to move.

Facilitated DiffusionFacilitated Diffusion

Facilitated Diffusion: a process in which substances move down their concentration gradient across the cell membrane with the assistance of a membrane protein Examples: glucose, fructose, water &

ions

Facilitated Diffusion: a process in which substances move down their concentration gradient across the cell membrane with the assistance of a membrane protein Examples: glucose, fructose, water &

ions

TwoTypes of Membran

e Proteins:

Channels&

Carrier Proteins

TwoTypes of Membran

e Proteins:

Channels&

Carrier Proteins

FacilitatedDiffusion

FacilitatedDiffusion

Aquaporins = Water Channels

Aquaporins = Water Channels

Gated ChannelGated Channel

Gated Channel: a protein-lined gated passage making cell membranes permeable to certain large molecules as needed Example: neuromuscular function

Gated Channel: a protein-lined gated passage making cell membranes permeable to certain large molecules as needed Example: neuromuscular function

Gated ChannelGated ChannelProtein keymade bynucleus

Protein keymade bynucleus

Review of Passive Transport

Review of Passive Transport

Section 2: Active TransportSection 2: Active Transport

Active TransportActive Transport

Active Transport: the movement of any substance across a cell membrane with the use of energy from ATP

Sodium-Potassium Pump Endocytosis Exocytosis

Active Transport: the movement of any substance across a cell membrane with the use of energy from ATP

Sodium-Potassium Pump Endocytosis Exocytosis

Sodium-Potassium PumpSodium-Potassium Pump

Sodium-Potassium Pump: an active transport mechanism that moves ions in order to achieve polarization

Sodium-Potassium Pump: an active transport mechanism that moves ions in order to achieve polarization

Proton PumpProton Pump

Proton Pump: an active transport mechanism that consumes ATP (energy) to force Hydrogen ions against the concentration gradient

Proton Pump: an active transport mechanism that consumes ATP (energy) to force Hydrogen ions against the concentration gradient

Proton PumpProton Pump

Proton Pump & Cotransport

Proton Pump & Cotransport

EndocytosisEndocytosis

Endocytosis: the process by which a cell engulfs and surrounds large substances

Endocytosis: the process by which a cell engulfs and surrounds large substances

PhagocytosisPhagocytosis

PinocytosisPinocytosis

Receptor-Mediated

Endocytosis

Receptor-Mediated

Endocytosis

ExocytosisExocytosis

Exocytosis: the process by which wastes are packaged in vesicles and leave the cell

Exocytosis: the process by which wastes are packaged in vesicles and leave the cell

ExocytosisExocytosis

Passive vs. Active Transport

Passive vs. Active Transport

Homeostasis & Transport. Section 1: Diffusion & Osmosis.

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