How can carbon dioxide produce chips?

What is happening here?

Carbon dioxide

SunlightGlucose

OxygenWater

Photosynthesis

Limiting factors

What can affect the rate of photosynthesis?

Limiting factors

What can affect the rate of photosynthesis?

Less light = plant photosynthesises slowlyEven if there is a lot of

water and carbon dioxide

More light = faster photosynthesis

Less carbon dioxide = slower photosynthesisEven if there is a high

light intensity

More carbon dioxide = faster photosynthesis

Too cold/too hot = slower

photosynthesisEven if other variables

are there

Optimum temperature = faster photosynthesis

Limiting factorsWhat can slow the rate of photosynthesis?

Light Intensity

Graph:

Description:

Carbon dioxide

Graph:

Description:

Temperature

Graph:

Description:

What does the plant do it for?

Glucose:- Used in respiration and growth - Stored as starch (insoluble)

Oxygen: - By product (waste)- Let back out into atmosphere

Glucose

1. Energy2. Cellulose in cell walls3. New chlorophyll

Stored as starch as it is insoluble

TUBER

Create a story board to explain the journey from carbon dioxide to a chip

State the word equation for

photosynthesis

Describe the limiting factors

of photosynthesis

Explain how plants use the glucose they produce in

photosynthesis

Your Task

Over the Christmas holidays create an exploration for the following experiment:

- Investigate limiting factors on photosynthesisChoose one of the three we have learnt aboutUse the exploration criteria to complete this, also look at the exploration you completed for enzymes – how could you improve?

Due: Tuesday 6th January

Make sure you also revise for your SAW test

2.9 Photosynthesis

Understanding:- Photosynthesis is the production of carbon

compounds in cells using light energy- Visible light has a range of wavelengths

with violet the shortest wavelength and red the longest

- Chlorophyll absorbs red and blue light most effectively and reflects green light more than other colours

- Oxygen is produced in photosynthesis from photolysis of water

- Energy is needed to produce carbohydrates and other carbon compounds

- Temperature, light intensity and carbon dioxide concentration are possible limiting factors on the rate of photosynthesis

Applications:- Changes to the Earth’s atmosphere,

oceans and rock deposition due to photosynthesis

Skills:- Design of experiments to investigate

limiting factors on photosynthesis- Separation of photosynthetic

pigments by chromatography- Drawing an absorption spectrum for

chlorophyll and an action spectrum for photosynthesis

Nature of science:- Experimental design: controlling

relevant variables in photosynthesis experiments is essential

Photosynthesis

Plants are able to make their own energy using sunlight and simple

carbon compounds.

Carbon dioxide + water glucose + oxygen

Energy converts from light energy to chemical energy

Wavelengths of light

Light is made up of many wavelengths

Some wavelengths are invisible to us

Wavelengths of light

Too short to see: X-rays, UV rays

Too long to see: Infrared

Visible light range from 400 to 700 nanometres

Photosynthesis

Wavelengths of light detected by human eye also used in photosynthesis

They are the most abundant wavelengths on earth so plants have adapted to use these

Pigments

Pigments are substances that absorb light – therefore appear coloured to us

If a pigment absorbs all colours, it appears black as it emits no light

Some pigments only absorb certain wavelengths of light

Pigments

Gentian flower absorbs all colour except blue

So it appears blue

This part of sunlight is reflected and can pass into our eye.

Chlorophyll

There are various forms of chlorophyll but they all appear green to us

They absorb red and blue light

Green light is absorbed less effectively so is reflected

This is why plants look green!

Spectra

ActionShows rate of photosynthesis at each wavelength of

light

AbsorptionPercentage of light absorbed at each wavelength of

each pigment

Rules to draw spectra

Action Absorption BothY-axis should be used

for rate of photosynthesis – often given as a

percentage of the maximum rate (0-

100%)

Y-axis should be labelled % absorption

(0-100%)

Horizontal axis should have label:

wavelength (nm)

Scale from 400-700 nm for wavelength

Separating Photosynthetic pigments

Chloroplasts have many types of chlorophyll and other accessory pigments

Because they absorb different wavelengths of light they look different colours to us

We can separate these pigments by chromatography

Separating Photosynthetic pigments

A spot containing leaf pigments is placed near one end of the strip of chromatography paper

A solvent is allowed to run up the strip

This separates out the different types of pigment – your experiment on Tuesday

Exploration

Finish exploration ready to hand in (hard copy) tomorrow in the lesson

If you have already finished this – revise for your SAW exam

Revise

Once you have completed your practical and your worksheet complete revision ready for your SAW test

Wednesday – Test and mark during lesson (marks not taken in – for your revision!)Photosynthesis and respiration

Thursday – Your own revision so bring in any resources you need