CHAPTER 8 PHOTOSYNTHESIS

CHAPTER 8 PHOTOSYNTHESISSECTION 8-1ENERGY and LIFEQuestion of the Day OCT 25Which of the following organisms is an autotroph?A. GiraffeB. AntelopeC. Maple treeD. Polar bearDO NOW OCT 25ITS BACK!!!

ADAM C., NICOLE L., and TYLER YOU are the next contestants on DO NOW CHALLENGE!!!DO NOW CHALLENGE OCT 25Explain why plants have a key role in the survival of all living things.

Answer the DO NOW in your notes if you are at your desk.

DO NOW ANSWEREDPlants (and some algae) perform photosynthesis. They produce their own food in the form of sugar.

Other living organisms depend on this source of food to power their own cells.

Ultimately, all life is dependent upon plants from the smallest herbivore to the pinnacle predators of our planet. AGENDA OCT 25BIG Question: How do organisms obtain and store energy?

1. QoD and DO NOW2. Introduce Chapter 8 Photosynthesis3. Review Guided Notes Packet4. REVIEW5. HOMEWORK and Closing ThoughtsAUTOTROPHS AND HETEROTROPHSWhat is the key source of energy for most food?THE SUNPlants and other organisms such as blue-green algae use light energy from the sun to produce food.These organisms are called AUTOTROPHS.Use simple inorganic molecules to do this.

AUTOTROPHS and HETEROTROPHSHeterotrophs are organisms that obtain energy from the food they consume.Unable to use sunlight directly.

ALL organisms must release energy in sugars and other compounds.

CHEMICAL ENERGY and ATPWhat are three forms of energy?Light, heat, and electricity

Energy can be stored in compounds.

Electrons release energy when a piece of wood is set on fire.

When chemical bonds are broken and electrons shift from higher energy levels to lower energy levels, the extra energy is released as light and heat.

CHEMICAL ENERGY and ATPHow do organisms such as humans store and release energy?Cells use chemical compounds to do this.

What is ATP?Adenosine Triphosphate (ENERGY storing molecule)

ATP consists of ADENINE, a 5-CARBON SUGAR, and 3 PHOSPHATE GROUPS

STORING ENERGYWhat is ADP?ADENOSINE DIPHOSPHATE2 PHOSPHATE GROUPSPartially charged batteryThis is the key molecule organisms use to store excess energy when it is available.

To store energy, a PHOSPHATE group is added to ADP.

This creates a molecule of ATP.

ATP is like a fully charged battery. WHY?RELEASING ENERGYHow is stored energy released from ATP to be used by the cell?Energy is stored in the chemical bond between the second and third phosphate groups.

Breaking this bond releases the energy stored in it.

RELEASING ENERGYATP is the basic energy source for all cells.

What are different cellular functions that ATP can power within the cell?

ACTIVE TRANSPORT

PROTEIN SYNTHESIS

MUSCLE CONTRACTION

USING BIOCHEMICAL ENERGYWhat is a SODIUM POTASSIUM Pump?Used during Active TransportIt pumps Na- ions out of the cell and K+ ions into itBalance of ions must be carefully regulated.

Why do most cells only have a small amount of ATP?Not a good molecule for storing large amounts of energy over a long period of time.Glucose stores 90 times more energy than ATP

Cells regenerate ATP from ADP as they need it.QUESTION OF THE DAY OCT 28Where is energy stored in a molecule of ATP?

The phosphate groupsThe ribose The bond between the first and second phosphatesThe bond between the second and third phosphatesDO NOW CHALLENGE OCT 28STEP UP to the boards.

Answer the Challenge in your notes if you are at your desks.DO NOW CHALLENGE OCT 28Compare a molecule of ATP and Glucose.

How are they similar/different in their role of storing energy?ANSWEROCT 28ATP is the cells short term energy storing molecule. Energy is stored within ATP in the chemical bond formed between the second and third phosphate groups of the molecule. In order to release this energy, the bond must be broken.

Glucose is a monomer that forms carbohydrates. Many of these simple sugars form glycogen. It is used to store sugars for long term energy use.

THANK YOU FOR PLAYING DO NOW CHALLENGE!!!AGENDA OCT 28BIG QUESTION: How did early experiments lead to the discovery of photosynthesis?

1. QoD and DO NOW2. Section 8-2 Photosynthesis: An Overview3. Discovery of Photosynthesis4. Homework Check5. Review and Homework6. Return CH 7 Tests and Cell Booklets

8-2 Photosynthesis: An OverviewWhat is PHOTOSYNTHESIS?

Plants use the energy of sunlight to convert water and carbon dioxide into high energy carbohydrates Sugars and starches

And Oxygen, a waste product.

Investigating PhotosynthesisAs a tree grows bigger and bigger in size, where does the trees increase in mass come from?

SOIL, WATER, AIR?

This simple question asked hundreds of years ago began the research into photosynthesis.

Lets take a closer look at some of the experiments that led to the discovery of photosynthesis

Van HELMONTS Experiment1643, Belgian physician Jan van Helmont.

What did he do?Designed an experiment to investigate if plants grew by taking materials out of the soil.

His experiment?1. Determined mass of a pot of dry soil and a seedling.

Van HELMONT Experiment2. Planted the seedling in the pot of soil.Watered regularly.3. At the end of 5 years, the seedling had grown into a small tree. Mass gain of 75 grams.4. Mass of soil remained almost unchanged.5. His ConclusionMass of the tree came from the water only thing he added.Accounted for the HYDRATE portion of a CARBOHYDRATE

Where does the CARBO portion come from?Carbon DioxidePriestleys Experiment1771, English minister Joseph Priestley

What did he do?

Lit a candle, placed a jar over it, and watched the flame gradually die out.

What did he reason about the candle flame?Something in the air was necessary to keep the candle burning. Priestleys ExperimentWhat was his next step?He placed a spring of mint underneath the jar with the candle.

After a few days, Priestley realized that the candle could be relighted.It would remain burning for a period of time.

His conclusion?The mint sprig released something needed to keep the candle flame burning.What was this mystery substance?OXYGEN

The Ingenhousz Experiment1779, Dutch scientist Jan Ingenhousz

What did he do?Showed the effect observed by Priestley only occurred when the plant was exposed to light.

What did these experiments show?When a plant is exposed to light, it transforms carbon dioxide and water into carbohydrates and release oxygen.

PHOTOSYNTHESIS EQUATIONWhat is the balanced equation of photosynthesis?

Compare the equation of photosynthesis with another cellular process.

Light and PigmentsWhite light is actually a mixture of different wavelengths of light called the visible spectrumDifferent wavelengths of visible light are seen as different colors.

Light and PigmentsWhat is a pigment?colored substances that absorb or reflect light

Why are plants green?chlorophyll: principle pigment in green plantsAbsorbs red and blue-violet light in the visible spectrum.Chlorophyll a and Chlorophyll b

Does not absorb green light well.

Leaves reflect green lightWhich is why plants look green.

ABSORPTION OF LIGHT

B caroteneRed and orange pigments that absorb light in other regions of the spectrum.