Free Powerpoint Presentations

Resource Acquisition and Transport in Vascular Plants
Page
2

DOWNLOAD

WATCH ALL SLIDES

Diffusion across a membrane is passive transport. The pumping of solutes across a membrane is active transport and requires energy.

Most solutes pass through transport proteins embedded in the cell membrane.

Slide 9

The most important transport protein for active transport is the proton pump.

The most important transport protein for active transport is the proton pump.

Proton pumps in plant cells create a hydrogen ion gradient that is a form of potential energy that can be harnessed to do work.

They contribute to a voltage known as a membrane potential.

Slide 10

Proton pumps provide energy for solute transport

Proton pumps provide energy for solute transport

CYTOPLASM

EXTRACELLULAR FLUID

ATP

H+

H+

H+

H+

H+

H+

H+

H+

H+

Proton pump generates mem- brane potential and gradient.

+

+

+

+

+

_

_

_

_

_

Slide 11

Plant cells use energy stored in the proton gradient and membrane potential to drive the transport of many different solutes.

Plant cells use energy stored in the proton gradient and membrane potential to drive the transport of many different solutes.

The coat-tail effect of cotransport is also responsible for the uptake of the sugar sucrose by plant cells.

Slide 12

Solute transport in plant cells

Solute transport in plant cells

CYTOPLASM

EXTRACELLULAR FLUID

K+

K+

K+

K+

K+

K+

K+

Transport protein

_

_

_

_

+

_

+

+

+

+

(a) Membrane potential and cation uptake

NO3−

NO3−

NO3−

NO3−

NO3−

NO3−

H+

H+

H+

H+

H+

H+

H+

H+

H+

H+

H+

H+

(b) Cotransport of an anion with H+

H+

_

_

_

_

_

_

+

+

+

+

+

+

H+

H+

H+

H+

H+

H+

H+

H+

H+

H+

H+

H+

_

_

_

_

_

_

+

+

+

+

+

+

(c) Cotransport of a neutral solute with H+

S

S

S

S

S

S

Slide 13

Cotransport - a transport protein couples the diffusion of one solute to the active transport of another.

Cotransport - a transport protein couples the diffusion of one solute to the active transport of another.

NO3−

NO3−

NO3−

NO3−

NO3−

NO3−

H+

H+

H+

H+

H+

H+

H+

H+

H+

H+

H+

H+

_

_

_

_

_

_

+

+

+

+

+

+

Cotransport of an anion with H+

Slide 14

Diffusion of Water = Osmosis

Diffusion of Water = Osmosis

To survive, plants must balance water uptake and loss.

Osmosis determines the net uptake or water loss by a cell and is affected by solute concentration and pressure.

Go to page:
 1  2  3  4  5  6  7  8  9  10 

Contents

Last added presentations

2010-2019 powerpoint presentations