The Plasma Membrane And Cell Wall 5.2

Front 1

What is the cell membrane also called ?

Back 1

The cell wall

Front 2

What is the plasma memebrane ?

Back 2

It sets the boundary for the space that the cells contents occupy. And most importantly it creates the correct environment for the cell internally.

Front 3

Cell wall

Back 3

The cell wall in different groups of organisms is external to the plasma membrane and it maintains the shape and internal environment of the cell.

Front 4

What is homeostasis ?

Back 4

keeping a constant environment actively through maintenance

Front 5

How does the plasma membrane maintain homeostsis ?

Back 5

It acts as a selective barrier by selecting which molecules enter and which dont.

Front 6

how can the membrane act as a selective barrier ?

Back 6

This is the result of the arrangement of lipids and embedded proteins. Hydrophobic lipid bylayer prevents polar, charged, ions and large molecules from entering.

Front 7

What molecules can diffuse into the plasma membrane freely ?

Back 7

Small molecules , small polar molecules and other lipids

Front 8

What do protein transporters allow ?

Back 8

molecules that are necessary to the cel such as ions nutrients and molecules that cannot cross the cell membrane they import and export through transport proteins

Front 9

Why is the identity of the membrane associated proteins important ?

Back 9

They are important because depending on the type of protein it can give the cell different functions.

Front 10

What is the simplest form of movement in and out of a cell called ?

Back 10

Passive transport.

Front 11

What is diffusion ?

Back 11

random.movement of molecules. A net movement from higher to lower concentration. diffusion continues even if there is net movement of solutes.

Front 12

What is one example of a molecule that is able to diffuse through a plasma membrane ?

Back 12

tracylglycerols being that theyre hydrophobic it would make sense that theyre able to diffuse in a lipid bilayer.

Front 13

What is facilitated diffusion ?

Back 13

When a molecule goes passively through a membrane protein channel or carrier and bypasses the lipid bilayer.

Front 14

How do carriers allow for molecules to go through ?

Back 14

Carrier proteins allow selective molecules to exit or enter the bilayer membrane and the conformation of the protein changes when the molecule.of interest binds to it allowing entrance to either side.

Front 15

What are aquaporins ?

Back 15

Aquaporins are protein channels that allow water to enter the cell and bypass the lipid layer aka facilitated diffusion. In addition, water is a small molecule therefore can passively entet the cell to a certain extent.

Front 16

Whatbia the technical term.for.the movement of water ?

Back 16

osmosis

Front 17

When do the concentration work at an advantage for passive transport ?

Back 17

When taking in nutrients, the advatange is going from higher externally to lower internally. When releasing waste it is of advantage when going from lower externally to higher internally.

Front 18

How can the cell take up molecules from lower external concentration into higher internal concentrations ?

Back 18

Active transport

Front 19

What does the active transport need to function ?

Back 19

It needs energy

Front 20

Where does most of the energy of a cell go into ?

Back 20

Most of the energy from a cell goes into the proteins in the membrane transporting molecules to keep the internal environment different from the outside.

Front 21

During active transport what do proteins act like and provide an example.

Back 21

The proteins act like a pump, pumping ions and molecules against a gradient. For example the sodium/potassium pump protein. Pumps Na out into high concentration and pumps k into high concentration as well.

Front 22

What is primary active transport ?

Back 22

When ATP energy is used directly to transport molecules against a gradient.

Front 23

What do you call proteins that move ions in different directions and ones that move ions in the same direction ?

Back 23

Antiporters is different direction and symporter or cotransporters is the same direction.

Front 24

Secondary Active Transport

Back 24

To make the transportation of ions possible they will pump a bunch of ions on the external side using ATP. Creating a higher to lower gradient however they cannot get through because of lipid bilayer. also the outside has a positive charge while inside creates less charge as a result you have an electric gradient.

Front 25

What results from an excessive positive chatge on one side and negative on one side.

Back 25

An electric gradient results from such differences.

Front 26

The movement of protons happens from higher to lower or lower to higher gradient ?

Back 26

it happens from higher to lower

Front 27

The movement of a coupled molecule happens in a what gradient ?

Back 27

It happens from lower to higher

Front 28

Why is it called secondary active transport ?

Back 28

Because coupled molecules are transported by the movement of protons and thats makes it secondary while atp is primary

Front 29

Define hypotonic, hypertonic, very hypotonic and isotonic.

Back 29

Hypotonic is when extracellular fluid is less concentrated and water moves into the cell to dilute and can cause lysing of a cell. Hypertonic is high concentration in extracellular fluid and causes water to come out of the cell causing shrinkge and isotonic is the balanced concetration between the two.mediums.

Front 30

Contracile Vacuoles

Back 30

The ability of a cell to take up lots of water and expel it, preventing lysing of the cell used in hypotonic situations. The mechanism of taking in water can differ from organisms. proton pump or aquaporins.

Front 31

How do cells maintain their shape size and composition with active transport?

Back 31

Isotonic (same concentration as extracellular fluid) in animal cells