Upload
reynold-anderson
View
219
Download
0
Tags:
Embed Size (px)
Citation preview
Warm – Up
Stomata-small openings in leaves that allow gases and water to diffuse into and out of the leaf
Guard cells – special cells that surround the stomata. Control the opening and closing of stomata
http://www.proprofs.com/quiz-school/upload/yuiupload/717044899.jpg
Warm-up Under what conditions would a plant close the
guard cells on its leaves? Analyze why this is an important ability for
plants. (Hint: Think reactants and products for
photosynthesis)
PHOTOSYNTHESIS
Parts of a Leaf
Most photosynthesis occurs in the palisade/palisade mesophyll layer
8.1 PhotosynthesisDefinition: Process of turning light energy from the sun into chemical
energy
6CO2 + 6H20 + the sun’s energy C6H12O6 + 6O2Carbon Dioxide
Water Glucose OxygenENERGY STORED
Requirements of Photosynthesis
A. Carbon dioxideB. WaterC. Sunlight
Requirements of photosynthesisD. Pigments 1. Pigments – colored substances that absorb or reflect light 2. The process of photosynthesis begins with plant pigments absorbing light energy 3. The main pigment in green plants is chlorophyll. Chlorophyll absorbs mostly red and blue light and reflects most green and yellow light.
http://science.hq.nasa.gov/kids/imagers/ems/visible.gif
Requirement of photosynthesisE. Energy storing compounds
1. Include ATP and NADPH 2. ATP and NADPH are produced during the light reactions 3. ATP and NADPH are used to drive the dark/ light independent reactions/Calvin Cycle
F. Photosynthesis also requires enzymes
8.1 ChloroplastsA. Site of photosynthesis in plants B. Contain CHLOROPHYLLC. Absorbs light energy
2. THYLAKOIDSSaclike photosynthetic
membranes (photosystems found inside)
Light-collecting units of chloroplast (contain pigments
and proteins)
PHOTOSYSTEMS
3. STROMARegion outside
thylakoid membranes (Calvin cycle occurs here)
6. GRANUMStack of
thylakoids
5. INNER MEMBRANE
4. OUTER MEMBRANE
8.1 Photosynthesis: Overview
LIGHT REACTION• Requires Light• Occurs in
Thylakoids
CALVIN CYCLE• Links carbon atoms
to make glucose • Occurs in Stroma
8.1 Photosynthesis: Overview
LIGHT-DEPENDENT REACTIONS
1. Requires light
2. Uses energy from light to produce oxygen gas and energy carriers: ATP and NADPH by splitting water
CALVIN CYCLE (Light Independent)
1. Does NOT require light
2. Uses ATP and NADPH from light-dependent reactions to produce high-energy glucose from CO2. Glucose can be stored for a long time.
The light-dependent reactions KEY CONCEPT-The light reactions convert
the energy from the sun into energy in ATP and NADPH (energy storing compounds).
The light reactions require light. Light energy splits water (this is why these
reactions are sometime called photolysis) When water is split oxygen, hydrogen ions, and electrons are released.
The light-dependent reactions The electrons travel across an electron
transport chain. Electron transport chain – series of
electron carrier proteins that shuttle high-energy electrons.
These electrons are eventually used to make NADPH.
The light-dependent reactions The hydrogen ions travel across the
thylakoid membrane and are eventually used to produce ATP.
The energy storing compounds (ATP and NADPH) that are produced during the light reactions drive the light-independent reactions.
Light-independent reactions/Calvin Cycle Key concept-the light-independent
reactions convert the ATP and NADPH into the high energy sugars (including glucose)
The light-independent reactions do not require light (hence the name)
Calvin Cycle (Light Independent Reactions
CO2 enters the Calvin Cycle and is added to a carbon chain with energy.
Additional Energy is used to modify the carbon chain and create carbohydrates (sugars)
Reactants – ATP, NADPH, and CO2
Products – Glucose, ADP, and NADP+
Location – Stroma
8.3 Photosynthesis Summary
Chloroplast
LightH2O
O2
CO2
Sugars
NADP+
ADP + P
Calvin Cycle
Light- dependent reactions
Calvin cycle
Factors Affecting Photosynthesis
Amount of H2O
Temperature
Intensity of Light