Active Transport Topics 2.6 and 2.9 Active Transport Overview - - PowerPoint PPT Presentation

▶

Mar 04, 2023 8 likes •213 views

Active Transport Topics 2.6 and 2.9 Active Transport Overview Requires free energy (ATP) to move molecules Active Transport: Membrane Pumps Uses membrane proteins embedded in the membrane to move solutes against their gradients

SLIDE 1

Active Transport

Topics 2.6 and 2.9

SLIDE 2

Active Transport Overview

Requires free energy (ATP) to move molecules

SLIDE 3

Active Transport: Membrane Pumps

Uses membrane proteins embedded in the

membrane to move solutes against their gradients

Allows cells to maintain concentration

gradients that differ from their surroundings

Some pumps establish and maintain

membrane potentials (voltage)

Examples: sodium-potassium pump, proton

pump

SLIDE 4

Factors Affecting Cellular Transport

Chemical driving force
Electrical driving force
Electrochemical driving force (combination)

SLIDE 5

SLIDE 6

Sodium-Potassium Pump

(video link – please watch – 2:26)

Pumps sodium ions (Na+) out of the cell and

potassium ions (K+) into the cell

Regulates osmolarity of cytosol by controlling

the solute concentration inside the cell

Maintains and restores the resting potential
f cells, such as neurons, cardiac and kidney
Primary pump in animal cells

SLIDE 7

SLIDE 8

Nerve Cell Signaling

(video link – please watch – 2:52)

SLIDE 9

SLIDE 10

Proton Pump

(video link – please watch – 1:04)

Moves protons (H+) against the concentration

gradient in order to generate a proton gradient across the membrane

Used in the synthesis of ATP during cellular

respiration

Causes changes in pH

SLIDE 11

Active Transport: Bulk Transport

Involves changes in the membrane structure
Transports macromolecules (proteins,

polysaccharides, etc.) by packaging the materials into vesicles

SLIDE 12

Exocytosis

Cell secretes large molecules by fusion of the

vesicles with the cell membrane

SLIDE 13

Exocytosis Example

Release of neurotransmitters between neurons

SLIDE 14

Endocytosis

Region of the cell membrane sinks inward and

pinches off to form a vesicle to bring extracellular material into the cell

SLIDE 15

Endocytosis: Phagocytosis

Cells engulf large particles or other cells using

pseudopods

Example: white blood cell consuming bacteria,

ameba consuming food

SLIDE 16

SLIDE 17

Endocytosis: Pinocytosis

Droplets of extracellular fluid are taken into

the cell in small vesicles

Example: Uptake of nutrients by the microvilli
f the small intestine

SLIDE 18

Receptor-Mediated Endocytosis

Enables cells to acquire specific substances

from extracellular fluid

Molecules bind to receptors
Example: cholesterol uptake from the blood

SLIDE 19

SLIDE 20

Review of Cellular Transport

(video link – please watch – 4:44)