Photosynthesis
This presentation is the property of its rightful owner.
Sponsored Links
1 / 22

Photosynthesis PowerPoint PPT Presentation


  • 51 Views
  • Uploaded on
  • Presentation posted in: General

Photosynthesis. Energy & Life. Photosynthesis is the process of capturing and transforming the energy of sunlight into chemical energy. (What type of organisms can make their own food?) a. Autotrophs – organisms that can make their own food

Download Presentation

Photosynthesis

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript


Photosynthesis

Photosynthesis


Energy life

Energy & Life

Photosynthesis is the process of capturing and transforming the energy of sunlight into chemical energy. (What type of organisms can make their own food?)

a. Autotrophs – organisms that can

make their own food

b. Heterotrophs – organisms that

obtain energy from the food they

consume


Energy life1

Chemical Energy and ATP

a. ATP – energy molecule used by cells (Fig. 8-2)

b. Energy is stored in the bonds between phosphate

c. When these bonds are broken energy is released

Energy & Life


Energy life2

Energy & Life


Energy life3

Using Biochemical Energy

a. Active Transport

http://www.dnatube.com/video/359/Active-Transport

b. Motor proteins move organelles

throughout the cell

http://www.youtube.com/watch?v=tL99pwdvmhU

c. Synthesize various molecules

Energy & Life


Photosynthesis an overview

Understand the significance of Helmont’s, Priestley’s, and Ingenhousz’s experiments.

6CO2 + 6H2 O 

C6H12O6 + O2

Photosynthesis: An Overview


Photosynthesis an overview1

  • Light and Pigments (Fig. 8-5)

    • A. Wavelength – distance between crests; shorter wavelengths have higher energy than longer wavelengths

Photosynthesis: An Overview


Photosynthesis an overview2

  • Light and Pigments (Fig. 8-5)

    • B. Photon – a particle of light

    • C. In photosynthetic organisms, absorbed energy is used to make chemical energy (glucose)

    • D. Photosynthetic pigment – molecule that absorbs light (color you see is the color being reflected)

    • 1. chlorophyll a - primary pigment; converts light energy to chemical

    • energy

Photosynthesis: An Overview


Photosynthesis an overview3

  • Light and Pigments (Fig. 8-5)

    • D. Photosynthetic pigment (con’t)

    • 1. chlorophyll a - (con’t)

    • a. reflects green light

    • b. absorbs red & blue light

    • c. normally hides other

    • pigments

    • 2. Chlorophyll b – accessory

    • pigment; absorbs light and

    • transfers the energy to

    • chlorophyll a

Photosynthesis: An Overview


Photosynthesis an overview4

  • Light and Pigments (Fig. 8-5)

    • D. Photosynthetic pigment (con’t)

    • 3. carotenes & xanthophylls –

    • accessory pigment; colors

    • can be seen in autumn when

    • chlorophylls start to break

    • down

    • E. Absorption spectrum – the different

    • colors (wavelengths) of light

    • absorbed by each pigment

Photosynthesis: An Overview


Reactions of photosynthesis

  • Inside a chloroplast – organelle in

    • which photosynthesis occurs

Reactions of Photosynthesis


Reactions of photosynthesis1

  • Inside a chloroplast

  • A. Thylakoids – flattened sacs of photosynthetic membranes; pigments and proteins are organized into photosystems in order for light energy to be captured & stored as chemical energy

  • B. grana – stacks of thylakoids

  • C. stroma – region between grana

Reactions of Photosynthesis


Reactions of photosynthesis2

  • II. Electron Carriers – molecules that can accept a pair of high-energy electrons and protons and transfer them to another molecule (NADP+)

Reactions of Photosynthesis


Reactions of photosynthesis3

  • There are two sets of reactions that take place within the chloroplasts: The light dependent reactions & the Calvin Cycle (also know as the light independent or the dark cycle)

Reactions of Photosynthesis


Reactions of photosynthesis4

  • Light Dependent Reactions

  • A. Takes place only in the presence of light

  • B. Occurs on membranes of thylakoids

  • C. Produces high energy compounds that are used in the dark reaction: ATP and NADPH

  • D. Photosystem II

  • 1. pigments absorb light energy and electrons are boosted to a higher energy level

Reactions of Photosynthesis


Reactions of photosynthesis5

  • Light Dependent Reactions

  • D. Photosystem II (con’t)

  • 2. lost electrons are replaced by the splitting of H2O into 2 e-,2 p+, and O2

  • a. electrons are picked up by NADP

  • b. protons (H+) are pumped into inner thylakoid space

Reactions of Photosynthesis


Reactions of photosynthesis6

  • Light Dependent Reactions

  • E. Photosystem I

  • 1. pigments use energy from light to re- energize the elctrons from photosystem II

  • 2. produces NADPH which also powers the Calvin Cycle

Reactions of Photosynthesis


Reactions of photosynthesis7

  • Light Dependent Reactions

  • http://www.youtube.com/watch?v=Oi2_n2wbB9o

Reactions of Photosynthesis


Reactions of photosynthesis8

  • The Calvin Cycle – (light independent, dark reaction) – uses ATP and NADPH from the light dependent reactions to produce high energy sugars (Fig. 8-11)

    • A. Takes place with or without the presence of light as long as ATP and NADPH are available

    • B. Occurs in the stroma of chloroplast

    • C. 6CO2 molecules enter the cycle from the atmosphere and combine with 6 five carbon molecules

Reactions of Photosynthesis


Reactions of photosynthesis9

  • The Calvin Cycle (con’t)

    • D. The resulting 12 three carbon molecules use the energy from ATP and NADPH to produce 12 high energy three carbon molecules

    • E. 2 of these molecules are used to synthesize sugar and other compounds

    • F. The remaining 10 molecules are used to produce more of the “starting” 6 carbon molecule of the cycle

Reactions of Photosynthesis


The calvin cycle http www youtube com watch v nihg1qa l0

The Calvin Cyclehttp://www.youtube.com/watch?v=_NIhg1qa_L0


Reactions of photosynthesis10

  • FactorsAffectingPhotosynthesis

  • A. Light intensity – as intensityincreases the rate of photosynthesisincreases (up to a point)

  • B. Temperature – photosynthesisoccursrapidlyatspecifictemp.; extreme temps. are damaging to enzymes

  • C. H2O – decrease in water slows rate of photosynthesis

  • D. Minerals – must bepresent in certain amounts

Reactions of Photosynthesis


  • Login