PHOTOSYNTHESIS

http://www.youtube.com/watch?v=pE82qtKSSH4

Name one food that they ate in the last 24 hours.

THE LIGHT REACTIONS

All organisms use energy. They NEED energy to survive. Where does this energy come from? Plants get their energy from the sun.

OBTAINING ENERGY

These organisms are called autotrophs. These organisms use photosynthesis to make

their own food. This converts light energy from the sun into

food(mostly carbohydrates)

Not only do plants need this energy but animals depend on this as well. Why?

Think about the food chains and food webs

Photosynthesis involves a complex series of chemical reactions in which the product of one reaction is consumed in the next reaction.

This is called the biochemical pathway.

LIGHT REACTIONS

Light energy in converted into chemical energy, which is temporarily stored in ATP and the energy carrier (NADPH)

Calvin Cycle- Organic compounds are formed using CO2 and the chemical energy stored in ATP and NADPH

PHOTOSYNTHESIS CHEMICAL EQUATION

6CO2 + 6H2O C6H12O6 + 6O2

!!!!!!!!!!TEST QUESTION!!!!!!!!!

CAPTURING LIGHT ENERGY

The first stage in the reaction includes light reactions. This requires light for it to happen.

It begins when the chloroplasts absorbs the light. (what is chlorophyll?)

LIGHTS AND PIGMENTS

Light from the sun appears white. It is actually a variety of colors. When you see a color it is actually the color

that is reflected from that object. The other colors are absorbed by the object.

CHLOROPLAST PIGMENTS

Within the chloroplast are pigments called chlorophyll. These are the reason plants are green.

CONVERTING LIGHT ENERGY TO CHEMICAL ENERGY

CRITICAL THINKING 10 PTS.

Thinking about the main role of pigments in photosynthesis, explain how the pigments in colored objects such as clothes differ from that of plant pigments.

http://www.youtube.com/watch?v=pE82qtKSSH4

SCIENCE IN ACTION PG. 119

Read this article and answer the review questions at the bottom of the page. (1-3)

THE CALVIN CYCLE

This is the most common way that plants produce organic compounds.

It is a series of enzymes-assisted chemical reactions that produce a 3 carbon sugar.

The incorporation of CO2 into organic compounds is called carbon fixation.

STEPS IN THE CALVIN CYCLE

1- CO2 diffuses into the stroma, An enzyme combines each CO2 molecule with a 5 carbon molecule called RuBP…as a result it is a unstable 6 carbon molecule so it splits into 2, 3 carbon molecules.

2)- each 3 carbon molecule is converted into another 3 carbon molecule in a 2 part process. 1st step is they receive a phosphate from ATP. They then gain a hydrogen molecule.

3)- One of the molecules leaves the calvin cycle and is used in carb production.

4)- The remaining molecule is converted back into the calvin cycle and the process starts all over.

Stomata- small pores on the underside of leaves that aid in water control.

This is also where the CO2 enters for the Calvin Cycle.

OVERVIEW OF PHOTOSYNTHESIS

Photosynthesis happens in 2 stages- 1)- the light reactions- energy is absorbed

from sunlight and converted into chemical energy, which is temporarily stored as ATP or NADPH

2)- The calvin cycle- carbon dioxide and the chemical energy stored in ATP and NADPH are used to form organic compounds.

CULTURAL AWARENESS

American Indians have fought to keep their land in tact b/c they believe that if the plants die then so will they.

FACTORS THAT EFFECT PHOTOSYNTHESIS

Light intensity Carbon Dioxide levels Temperature

CELLULAR RESPIRATION

Glycolysis and fermentation:The complex process in which cells

make ATP by breaking down organic compounds.

This is basically the next step after photosynthesis.

OVERVIEW

Glycolysis- organic compounds are converted into 3 carbon molecules of pyruvic acid, producing a small amount of ATP and NADPH. This is an anaerobic process bc it does not require oxygen.

STEPS IN CELLULAR RESPIRATION

Organic compounds glycolysis pyruvic acid + ATP aerobic respiration CO2 + H2O + ATP

Biochemical pathway in which one 6 carbon molecule of glucose in oxidized to produce 2 three carbon molecules of pyruvic acid.

AEROBIC RESPIRATION

Has 2 major stages- the Krebs cycle and the electron transport chain.

This requires oxygen.

THE KREBS CYCLE

A biochemical pathway that produces CO2, hydrogen and ATP.

http://www.youtube.com/watch?v=2f7YwCtHcgk&feature=related (cellular resp. notes)