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A Look Into the Future

It is 100 years in the future and you are a research scientist. An enormous volcanic eruption has recently sent huge quantities of dust and ash into the atmosphere.

Working with a partner, make a list of how this event will affect each of the following:

1. photosynthesis

2. plant life

3. animal life

4. human societies

Section 8-3

Interest Grabber

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A Look Into the Future

1. photosynthesis

The rate of photosynthesis will decrease due to reduced sunlight.

Section 8-3

Interest Grabber

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A Look Into the Future

2. plant life

Plants will grow more slowly or die off due to decreased rate of photosynthesis.

Section 8-3

Interest Grabber

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A Look Into the Future

3. animal life

Animal populations will decrease after a while due to fewer plants for herbivores to eat. Fewer herbivores will eventually result in fewer carnivores. Also, less oxygen will be available.

Section 8-3

Interest Grabber

Interest Grabber Answers

4. human societies

Human societies will have to adjust their eating habits as some food species die out.

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8–3 The Reactions of Photosynthesis

A. Inside a Chloroplast

B. Electron Carriers

C.Light-Dependent Reactions

D.The Calvin Cycle

E. Factors Affecting Photosynthesis

Section 8-3

Section Outline

PHOTOSYNTHESIS

Light-Dependent Reaction

Click the image to play the video segment.

Video 3

Light-Dependent Reactions, Part 1

PHOTOSYNTHESIS HAPPENS IN CHLOROPLASTS

• _________________= saclike photosynthetic membranes inside chloroplast

• ____________________ = stack of thylakoids• __________ = space around thylakoid membranes

THYLAKOIDS

GRANUM (pl. grana)

STROMA

• LIGHT DEPENDENT REACTION• Requires ______________• Happens within________________• Made up of ___________________• Connected by ______________________• Uses light energy to change• ADP + P → _______• NADP+ + H + → _________• Breaks apart ______ molecules and

releases _____________

LIGHT

ATP

THYLAKOID membranes

PHOTOSYSTEMS I & II

ELECTRON TRANSPORT CHAIN

NADPH

H20oxygen

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Video 4

Click the image to play the video segment.

Chapter 08D.mpg

Video 4

Light-Dependent Reactions, Part 2

Chapter 08D.mpg

PHOTOSYNTHESIS HAPPENS IN CHLOROPLASTS

• Proteins in thylakoid membrane organize chlorophyll and other pigments into clusters called _____________________PHOTOSYSTEMS

HIGH ENERGY ELECTRONS require a special carrier, too

• ____________ is one• of the carriers that• cells use to transport• high energy electrons.

NADP+

NADP+________ + _____ + _____ → ____________2 e- H+

_______= nicotinamide adenine dinucleotide phosphateNADP+

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HydrogenIon Movement

Photosystem II

InnerThylakoidSpace

ThylakoidMembrane

Stroma

ATP synthase

Electron Transport Chain Photosystem I ATP Formation

Chloroplast

Section 8-3

Figure 8-10 Light-Dependent Reactions

Click the image to play the video segment.

Video 5

Calvin Cycle

• LIGHT INDEPENDENT REACTION• (also called _________________________)

• • DOES NOT require ____________• Happens in ___________

• NADPH donates _______________• ATP donates _________________• CO2 donates

_________________________ • to make __________•

LIGHT

CALVIN CYCLE

ENERGY

STROMA

Hydrogen

Carbon & oxygenGLUCOSE

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Chloroplast

Light

O2

Sugars

CO2

Light-Dependent Reactions

CalvinCycle

NADPH

ATP

ADP + PNADP+Chloroplast

Section 8-3 Figure 8-7 Photosynthesis: An Overview

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Photosynthesis

includes

of

take place intakes place in uses

to produce to produce

use

Light-dependentreactions

Calvin cycle

Thylakoidmembranes Stroma NADPHATPEnergy from

sunlight

ATP NADPH O2 Chloroplasts High-energysugars

Section 8-3

Concept Map

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ChloropIast

CO2 Enters the Cycle

Energy Input

5-CarbonMoleculesRegenerated

Sugars and other compounds

6-Carbon SugarProduced

Section 8-3Figure 8-11 Calvin Cycle

PHOTOSYNTHESIS OVERVIEW

BIOLOGY; MIller and Levine; Prentice Hall; 2006

PHOTOSYNTHESIS

Light-Dependent Reaction

Light-Independent

Reactions

Light & Water

Water & oxygen

ATP

NADPH

Carbon Dioxide (CH2O)n

PHOTOSYNTHESIS

Light-Dependent Reaction

Carbon Fixation

(Calvin Cycle)

Light & Water

Water

ATP

NADH

Carbon Dioxide sugars

Factors that Affect Photosynthesis

• ____________________• Water is one of the raw materials needed, so a• shortage of water can slow or stop

photosynthesis

AMOUNT OF WATER

http://www.hononegah.org/departments/Anderson/cactus.JPG

Desert plants and conifers that live in dry conditions have a waxy coating on their leaves to prevent water loss.

Factors that Affect Photosynthesis

• Photosynthesis enzymes function best between 0° C - 35° C

• • At temperatures above

or below this range,• photosynthesis will slow

or stop • • Conifers in winter may

carry out• photosynthesis only

occasionally

TEMPERATURE

http://www.sustland.umn.edu/maint/images/evergreen10.jpg

Factors that Affect Photosynthesis

• ____________________• More light increases rate of photosynthesis• up to a certain level until plant reaches its• maximum rate of photosynthesis

LIGHT INTENSITY

See effect of light experiment

http://206.173.89.42/REALTYWITHALOHA_COM/piphoto/funny%20sun%20with%20sunglasses.gif

http://www.teachnet.ie/foneill/exper.htm

SOUTH DAKOTA SCIENCE STANDARDS

• Chapter 8 - Photosynthesis: • The students will be able to:• explain the biochemical processes that a plant

uses in photosynthesis• explain the role ADP-ATP cycle has within the

chloroplast of the cell (9-12.L.1.1)• explain the light reaction (9-12.L.1.1)• explain the steps of photophosphorylation and

the Calvin Cycle (9-12.L.1.1)

SOUTH DAKOTA CORE SCIENCE STANDARDS

• 9-12.L.1.1. Students are able to relate cellular functions and processes to specialized structures within cells.

• Photosynthesis and respiration• ATP-ADP energy cycle

Role of enzymesMitochondriaChloroplasts

LIFE SCIENCE:Indicator 1: Understand the fundamental structures, functions, classifications, and mechanisms found in living things

Core High School Life SciencePerformance Descriptors

High school students performing at the

ADVANCED level:

explain the steps of photophosphorylation and the Calvin Cycle;

analyze chemical reaction and chemical processes involved in the Calvin Cycle and Krebs Cycle;

predict the function of a given structure;

High school students performing at the

PROFICIENT level:

describe and give examples of chemical reactions required to sustain life (…role of enzymes)

describe and give examples of chemical reactions required to sustain life (hydrolysis, dehydration synthesis, photosynthesis, cellular respiration, ADP/ATP, role of enzymes);

describe the relationship between structure and function

High school students performing at the

BASIC level

name chemical reactions required to sustain life (… role of enzymes)

name chemical reactions required to sustain life (hydrolysis, dehydration synthesis, photosynthesis, cellular respiration, ADP/ATP, role of enzymes);

recognize that different structures perform different functions;

SOUTH DAKOTA ADVANCED SCIENCE STANDARDS

• 9-12.L.1.1A. Students are able to explain the physical and chemical processes of photosynthesis and cell respiration and their importance to plant and animal life. (SYNTHESIS)

• Examples: photosystems, photophosphorylation, Calvin Cycle and Krebs Cycle

LIFE SCIENCE:Indicator 1: Understand the fundamental structures, functions, classifications, and mechanisms found in living things.

Light Dependent reactions Part 1

Light Dependent reactions Part 2

Calvin Cycle

See videoLIGHT-DEPENDENT REACTION