# Transport through membranes

which homework questions would you like me to discuss?
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Slide 1: Open question
BiologieMiddelbare schoolhavoLeerjaar 4

This lesson contains 19 slides, with interactive quizzes, text slides and 1 video.

Lesson duration is: 90 min

## Items in this lesson

which homework questions would you like me to discuss?

#### Slide 1 -Open question

AIM
• You can calculate the concentration of a solution.
• You can explain what diffusion and osmosis are and describe the role of osmosis in the rigidity of plants.
• You can describe how the transport of substances occurs through (cell) membranes.

#### Slide 2 -Slide

What is concentration?

#### Slide 3 -Mind map

Concentration
• In organisms, substances are dissolved in the cytoplasm of the cell.
• Living organisms require substances to enter and exit each cell.
• Chemical reactions take place in cells that can change the concentrations of solutes.

#### Slide 5 -Slide

Diffusion
The movement of a substance from an area of high concentration to an area of low concentration of that substance.

Diffusionspeed depends on the temperature.

#### Slide 6 -Slide

Osmosis
= diffusion of water through a semipermeable membrane

= the movement of water from a place with a low osmotic pressure to a place with a high osmotic pressure

Osmosis

#### Slide 8 -Slide

types of membranes
permeable =
a membrane with big pores, water and substances can move through the pores

semi-permeable or selectively permeable =
very small pores, only water can go through, not the dissolved substances

#### Slide 9 -Slide

Osmotic pressure
How much water moves is determined by the osmotic value on both sides of the membrane.

Osmotic value: amount of dissolved substances in the water.

High osmotic pressure: a lot of dissolved substances.
Low osmotic presurre: a few dissolved substances.

Water flows of a low > high osmotic value.

The solution with the highest osmotic pressure  has a suction force on the water from the other solution. This suction force is called the osmotic pressure.

#### Slide 10 -Slide

Osmosis in animal cells
hypotone solution OUTSIDE of the cell

water goes in by osmosis and the cells burst
isotone solution OUTSIDE of the cell

no osmosis, no difference in osmotic pressure
hypertone solution OUTSIDE of the cell

water leaves the cell through osmosis, the cells shrink

#### Slide 11 -Slide

osmosis in a plant cell

#### Slide 12 -Slide

passief transport
kost geen energie
verloopt altijd door een concentratieverschil
osmose en diffusie

#### Slide 13 -Slide

Actief transport, tegen concentratiegradiënt in. Kost ATP.
kost wel energie

#### Slide 14 -Slide

exo/endocytose
Exocytose:afsnoeren blaasjes (actief)
Endocytose: opnemen stoffen
-> endosoom.
Voeding opnemen: fagocytose

#### Slide 15 -Slide

Wat heb je onthouden van deze les?

#### Slide 16 -Open question

Waar zou je nog wat meer uitleg over willen hebben?

#### Slide 17 -Open question

Huiswerk
Leren 1.4 en 1.5
Maken t/m opdracht 51