Comparing Photosynthesis and Respiration The most important chemical reaction in the world is… The chemical reaction for photosynthesis is PHOTOSYNTHESIS

Comparing Photosynthesisand Respiration

The most important chemical reaction in the world is…

The chemical reaction for photosynthesis is

PHOTOSYNTHESIS

6CO2 + 6H2O + energy C6H12O6 + 6O2


PHOTOSYNTHESIS

6CO2 + 6H2O + energy C6H12O6 + 6O2

Carbon Dioxide

Water

Sunlight

Sugar

Oxygen


Stage 1

PHOTOSYNTHESIS

Chlorophyll in the Chloroplasts captures sunlight


Stage 2

PHOTOSYNTHESIS

The cell uses the captured sunlight, carbon dioxide and water to make food


Stage 2

PHOTOSYNTHESIS

Carbon Dioxide enters the plant through Stomata -small openings on the underside of the leaf

COMPARING PHOTOSYNTHESIS AND RESPIRATION

THE PHOTOSYNTHESIS - RESPIRATION CYCLEPHOTOSYNTHESIS

RESPIRATION

Organisms Use

Organisms Produce

Plants Produce

Plants useCarbon Dioxide

Water

Energy

Sugar

Oxygen


The process by which cells obtain energy from glucose

The chemical reaction for respiration is

RESPIRATION

C6H12O6 + 6O2 6CO2 + 6H2O + energy


RESPIRATION

C6H12O6 + 6O2 6CO2 + 6H2O + energy

Carbon Dioxide

Sugar Water

Oxygen


RESPIRATION Stage 1

Takes place in the cytoplasm

Molecules of glucose are broken down into smaller molecules

Oxygen is NOT involved

Small amount of energy is released


RESPIRATION Stage 2

Takes place in the Mitochondria

Small molecules are broken down into even smaller molecules

Oxygen is required

A great deal of energy is released

Carbon dioxide and water are also produced



RESPIRATION

Organisms Use

Organisms Produce

Plants Produce


Water

Energy

Sugar

Oxygen

Sugar

Oxygen

Carbon Dioxide

Water

Energy



Plants Produce


Water

Energy

Sugar

Oxygen


Testing Photosynthetic Rate of Elodea

Elodea – a common water plant

Elodea releases bubbles of oxygen as it photosynthesizes

Freshly cut Elodea stems produce more bubbles than the leaves



Materials Elodea

PlantsScissors Large

ContainerClear test tube Wate

rSunlight



ProceduresFill the large container half full of water

Cut the stem of the Elodea plant at an angle (for greater surface area)



ProceduresInsert the plant, cut stem first, into the test tube

Fill the test tube to overflowing with water



ProceduresCover the top of the test tube with your thumb

Invert the test tube over the beaker and put the test tube with your thumb still covering the opening into the beaker



ProceduresRelease your thumb and gently settle the test tube on the bottom of the container

Place the beaker and test tube in sunlight or under a bright lamp



ProceduresAt 5 minute intervals for a total of 15 minutes, record the number of bubbles producedMake a graph of your findings

Have someone in your group report out to the class


THE PHOTOSYNTHESIS - RESPIRATION CYCLE

RESPIRATION

Organisms Use

Organisms Produce

Sugar

Oxygen

Carbon Dioxide

Water

Energy


Respiration and Carbon Dioxide

Bromthymol Blue (BTB)

An acid-base indicator that can be used to measure levels of carbon dioxide (CO2)

BTB changes color from blue to green and then yellow as it gets more acidic



Bromthymol Blue (BTB)

If carbon dioxide is removed from the solution it will become more basic and change color moving to blue

If carbon dioxide is added to the solution it will become more acidic and change color moving to green and then yellow



This experiment uses Bromthymol Blue to examine the relationship between exercise and the amount of carbon dioxide you produce



Materials2 plastic cupsBromthymol Blue solution

2 straws

Timer

Paper towels



Procedure

Label one cup “1” and the other cup “2”

Fill both cups to the marked line with BTB



Procedure

Record the color in both cups on your lab sheet

Place a straw in cup 1



Procedure

Have a group member blow through the straw into the solution until it changes color

Have a group member time how long it takes for the solution to change color



Procedure

Record how long it took for the solution to change color on your lab sheet

Remember the solution is changing color because you are exhaling carbon dioxide into it



Procedure

Predict how long it would take the solution to change color after exercise

Record your prediction on your lab sheet



Procedure

Design an experiment to test your prediction

This means a group member must do some form of exercise (like jumping jacks)



Procedure

The exercise should be something you can do “in place” near your tables

Only one group member will perform the exercise



Procedure

Write down the steps of your experiment

Get your teacher’s approval BEFORE you begin your experiment



Procedure

Follow the directions in the Analyze and Conclude section of your lab sheet to conduct your experiment and record your results

Documents

Comparing Photosynthesis and Respiration The most important chemical reaction in the world is… The chemical reaction for photosynthesis is PHOTOSYNTHESIS