BSCI 230 Today, 2/22/01

•  Fund Raising Team: please pick up and edit the Web text I generated

BSCI 230 Today, 2/22/01

•  Exam 1 next Tuesday

–  Note special seating

–  Write your answers in ink

–  Be ready to begin at 9:30 AM

–  eCell will go silent ~ 10:00 PM Monday

Exam 1 next Tuesday

Note the Directions:

•  PRINT your name on each page of the examination NOW.  Do it now, please!

•  Answer each question in the space provided and only in the space provided.

Exam 1 next Tuesday

•  Complete the examination in pen if you wish the right to request a re-grade.

•  When you have completed the exam, sign the Honor Code statement at the bottom of this page before handing it in at the front of the room.

And our demotivational thought for the day…..

6 CO₂ + 6 H₂O ---> C₆H₁₂O₆ + 6 O₂

•  Reduction of C

–  Also called “fixing” or assimilating Carbon

•  DH is positive

– endothermic

•  DS is decreasing

•  DG is positive - endergonic

Photosynthesis

•  Energy Transduction

–  in the LIGHT reactions

–  Sunlight ---> Chemical energy (ATP)

–  Reducing power in the form of high energy electrons

•  Carbon assimilation

–  In the Dark reactions of the Calvin Cycle

Plastids

•  From meristem tissue with proplastids

•  Depending upon location in leaf

–  Chloroplasts

–  Amyloplasts - storing starch

–  Chromoplasts - pigments in flowers

–  Proteinoplasts - storing protein

–  Elaioplasts - storing lipids

Photosystems

•  Chlorophyll

•  accessory pigments - antenna pigments

•  associated proteins

•  Light harvesting complex (LHC)

•  Reaction Center

Two Photosystems

•  Photosystem II

–  P₆₈₀

–  Light energy --> e^- --> Pump protons (H⁺)

•  Photosystem I

–  P₇₀₀

–  Light energy --> e^- + NADP⁺ --> NADPH

P₆₈₀ & P₇₀₀

Absorption of photons alters their reduction potentials

From the Light Reactions NADPH and ATP
2:3 ratio Dark Reactions: Calvin Cycle Reduce atmospheric C as CO₂ into (CH₂O)