Transport in a Cell and Homeostasis

TRANSPORT IN A CELL AND HOMEOSTASIS

Passive Transport And Active Transport

I.  Homeostasis and the cell membrane

Homeostasis=______

•At the cell level it is maintained by the ______

•At the organism level it is maintained by ______

and the ______systems

The cell membrane is composed of

1.

diagram

2

diagram

These two make two layers called the

It is also known as

Small things like water, oxygen, and carbon dioxide enter through the ______.

•The cell membrane functions include

–H

–B

–T

–S

Passive transport

•Passive Transport uses ______

–Diffusion is the main form of passive transport

Diffusion is the movement of ______from a ______concentration to a ______concentration.

•High concentration = has high amounts of dissolved substances.

•Low concentration =has low amounts of dissolved substances.

•______=the difference between the concentration of the two substances

•Examples include

•1.

•2.

•The main examples of diffusion involve the transport of gases across membranes. This includes oxygen and carbon dioxide.

•______is due to diffusion

–Terrestrial vertebrates use ______

–Unicellular organisms use ______

-earthworms use skin ______

–Plants use ______

- Fish use ______

A special type of diffusion or passive transport is ______

Osmosis is the movement of ______across a membrane from a high concentration to a low concentration.

Osmosis involves ______

•Osmosis is ______.

–Passive it uses no ______

the direction the water moves is determined by the ______

-Water will always move from a ______concentration to a ______concentration.

This means water will move from a ______number on water to

A ______number on water.

Example

Or water will move from a small number on salt, sugar, syrup etc to a large number on salt sugar syrup etc.

Example

More Examples:

Plant and Animal Adaptations

To an environment with more water

•Plants have a______

–this means that when the vauole swells

–it will not break open

–it will merely get stiff

–this is known as

–the plant is said to be

–this means

•Animals lack a

•this means that when water enters it can swell or break open (lyse)

•when a cell breaks open it is called ______

•unicellular organisms have developed a ______

»this acts as a bilge pump

»it pumps out water

»Diagram

Adaptations to salt water

•Both plant and animal cells will loose water and ______or ______

•This is called plasmolysis

•Marine animals and plants live in a saltwater environment

–they have adapted to their lower water environments

–they have done this by making their fluids the same or isotonic

–they are the same so there is no net water gain

Remember in pure water you ______or ______

Remember in salt water salt sucks the ______out

•Active Transport is ______

–It goes from lo______to ______

•This is called against the ______

•It is like riding a bike uphill

•The energy comes from ______

•Diagram

–There are three main types

•Pumps =

•Endocytosis engulf large particles

•Exocytosis release large particles