Cell Function

Chapter 5

Transport in Cells

Section 1

ConcentrationAmount of particles/material in a

certain area

DiffusionMovement of particles from an area

of high concentration to an area of lower concentration

MembranesPermeable membrane: membrane

that lets molecules pass through it

Cell membranes are selectively permeable because only certain molecules can pass through

DiffusionCells need materials from their

environment, such as food, water, minerals.

They also need to get rid of waste molecules and move materials to other parts of organism

Cells don’t need to use energy for particles to diffuse

Diffusing WaterOsmosis: diffusion of water through a

selectively permeable membrane (cell membrane)

My Plant is Dying!How can osmosis prevent a plant

from wilting?

Moving Small Particles2 types of transport

1.Passive transport: particles are moved from areas of high concentration to areas of lower concentration without the cell having to use any energy to do it

Moving Small ParticlesWater and Oxygen can diffuse right

through the cell membrane because of their small size

Sugar and amino acids aren’t small enough so they have to go through protein “doorways” in the cell membrane

Moving Small Particles2. Active Transport: movement of

particles from areas of low concentration to an area of high concentration

Cells must use energy (ATP) to do this type of transport

Math and More Gases diffuse approximately 10,000 times

faster in air than in water. If a gas diffuses to fill a room completely in 6 minutes..

How long would it take the gas to fill a similar volume of still water?

How many hours would that be?

How many days?

Moving LARGE ParticlesEndocytosis: cell membrane

surrounds a particle and encloses it in a vesicle

This is how large particles, even other cells, can be brought into a cell

Moving LARGE ParticlesExocytosis: vesicles are formed at

the ER or Golgi and carry particles to the cell membrane

This allows large particles to be removed from the cell

Cell Energy

Section 2

From Sun to CellNearly all of the energy that fuels life

comes from the Sun

PhotosynthesisProcess by which plants are able to

capture light energy from the sun and change it into food

Chlorophyll captures the energy and the plant cell uses it to change CO2 and H20 into food, the simple sugar Glucose (C6H12O6)

Photosynthesis Glucose is a carbohydrate

When plants make glucose, they’re converting the sun’s energy into energy that can be stored

6CO2 +6 H2O + Light energy C6H12O6 + 6 O2

Getting Energy from FoodFood has to be broken down so that the

energy it contains can be converted into a form your cells can use

Cellular Respiration Glucose is broken down into CO2 and H2O and

energy is released

A lot of the energy is stored in the form of ATP but most of the energy is released in the form of heat.

This helps to maintain the body’s temperature

Cellular RespirationTakes place in mitochondria

Uses oxygen to break down the food

C6H12O6 + 6 O2 6 CO2 + 6H20 + energy (ATP)

FermentationOccurs when your muscle cells don’t get

enough oxygen to produce ATP through cellular respiration

Fermentation releases energy from sugar molecules without using oxygen

FermentationProduces 18x less ATP than cell respiration

Also produces Lactic Acid instead of CO2 and H20

Lactic acid is what causes the burning sensation and fatigue in your muscles

Fantasy IslandYou have been given the assignment of

restoring life to a barren island.

What types of organisms would you put on the island?

If you want to have animals on the island, what other organisms must be on the island as well? Explain your answer.

Review Questions 1. Why are producers important to the survival of all

other organisms?

2. How do the processes of photosynthesis and cellular respiration relate to each other?

3. What does breathing have to do with cellular respiration?

4. How are respiration and fermentation similar? How are they different?