ATP Adenosine Triphosphate (ATP) - One of the

principal chemical compounds that living things use to store and release energy

ATP

Made up of: 1. Adenine

2. 5-carbon sugar called ribose

3. Three phosphate groups (The key to ATP's ability to store and release energy.)

ATP vs. ADP

Adenosine Diphosphate – ATP minus one phosphate group

ATP – contains three phosphate groups (tri = three)

ADP – contains two phosphate groups (di = two)

Adenosine Triphosphate Adenosine Diphosphate

ATP and Energy

ATP is used by all types of cells as their basic energy source.

Energy is released when a phosphate is removed.

Where does the mass of a plant come from?

Photosynthesis

Heterotroph

Heterotroph - Organism that obtains energy from the foods it consumes; also called a consumer

Autotroph Autotroph - Organism that can capture energy

from sunlight or chemicals and use it to produce its own food from inorganic compounds; also called a producer.

Which organisms go through Photosynthesis?

Plants Photosynthetic Bacteria(ex. Cyanobacteria)

Some Protists(ex. Algae)

Photosynthesis

Photosynthesis - Process by which plants and some other organisms use light energy to convert water and carbon dioxide into oxygen and high-energy carbohydrates such as sugars and starches.

Photosynthesis Needed (Reactants):

1. Light

2. Water

3. Carbon dioxide

Given Off (Products):1. Sugars

2. Oxygen

Chlorophyll Photosynthesis also

requires chlorophyll, a molecule located in chloroplasts.

Chlorophyll - Principal pigment of plants and other photosynthetic organisms; captures light energy

Chlorophyll

Plants gather the sun's energy with light-absorbing molecules called pigments.

The plants' principal pigments are called chlorophyll. Chlorophyll does not absorb light well in the green

region of the spectrum therefore green light is reflected by leaves (this is why plants look green).

Chloroplast Vocabulary Thylakoids - Saclike photosynthetic membrane

found in chloroplasts. (where chlorophyll is found)

Stroma - Region outside the thylakoid membranes in chloroplasts

Two Sets of Reactions in Photosynthesis

1. The Light-Dependent Reactions

2. The Light-Independent Reactions (aka-Calvin Cycle)

These two chemical reactions work together!

Light-Dependent Reactions Takes place within the thylakoid membranes Requires light Requires: Water, ADP, and NADP+

Produce: Oxygen, ATP, and NADPH

Electron Carriers within the Light Dependent reaction

Inside the thylakoid, electrons within the chlorophyll become “excited” (gain energy) from the sunlight. Now that they have all this energy they require a carrier molecule : NADP+.

NADP+

NADP+

As soon as this carrier molecule NADP+ accepts the energy (from the electrons) it converts the NADP+ into NADPH.

This transfer of electrons and energy is called the Electron Transport Chain (ETC)

Light Dependent Reactions The sunlight breaks each water molecule into :

electrons H+ ions (released into thylakoid membrane) Oxygen atoms (released into the air)

Light Dependent Reactions As electrons are passed from chlorophyll to

NADP+, more hydrogen ions are pumped across the membrane. Inside of the membrane fills up with positively

charged hydrogen ions. Outside of thylakoid membrane becomes

negatively charged. The difference in charges across the membrane

provides the energy to make ATP. The H+ ions are important!

Light Dependent Reactions

ATP Synthase - Large protein/enzyme that uses energy from H+ ions to bind ADP and a phosphate group together to produce ATP. Spans the thylakoid membrane and allows H+ ions

to pass through it. Overall: Produce oxygen gas and convert ADP

and NADP+ into the energy carriers ATP and NADPH.

http://www.youtube.com/watch?v=eY1ReqiYwYs

The Light-Independent Reactions (Calvin Cycle)

Takes place in the stroma Uses ATP and NADPH from the light-

dependent reactions to produce high-energy sugars.

Calvin Cycle

Uses six molecules of carbon dioxide to produce one single glucose molecule.

Energy for this conversion comes from ATP and high-energy electrons from NADPH.

Factors Affecting Photosynthesis

1. Water A shortage of water can slow or even stop

photosynthesis.

2. Temperature Photosynthesis depends on enzymes that

function best between 0°C and 35°C.

3. Intensity of Light Increasing light intensity increases the rate of

photosynthesis...but a plant will reach a maximum rate.