Week 2, Lecture 3, Photosynthesis

Week 2, Lecture 3, Photosynthesis - Free Food Chemiosmosis...

Info iconThis preview shows pages 1–4. Sign up to view the full content.

View Full Document Right Arrow Icon
Photosynthesis Free Food Free Food Proplastid Chloroplast (photosynthesis) Leucoplast (storage) Chromoplast (color) B I O L O G Y 0 2 3 30-Dec-09 Gardiner 4 Chemiosmosis • Chloroplasts and Mitochondria generate ATP by the same basic mechanisms – Chemiosmosis • Oxidative phosphorylation = Mit. • Photophosphorylation = Chl. 30-Dec-09 Gardiner 5 Photophosphorylation (Chemiosmosis) • Electrons pass down the ETC • Cytochorme complex pumps H + from stroma to thylakoid lumen •H + high concentration in lumen and low concentration in stroma •A lso H + from splitting of water molecules 30-Dec-09 Gardiner 6 Photophosphorylation (Chemiosmosis) • Electrical gradient created • Proton-motive force • Provides energy for ATP synthase
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Fig. 7.10 IN THE DARK In acidic media H + enter stroma and thylakoid lumen In basic media H + leave stroma and thylakoid and ATP is generated without light The Calvin Cycle Carbon Fixation Reactions
Background image of page 2
Two components: Light energy H 2 O O 2 Light-dependent reactions Chemical energy ( ATP , NADPH ) Chemical energy ( ATP , NADPH ) H 2 O CO 2 Light-independent reactions Chemical energy (C H 2 O) The overall reaction in photosynthesis : CO 2 ++ + Light energy Photosynthesis (C H 2 O) O 2 Water split Carbon fixed Photosynthesis – What are we making? CO 2 + H 2 O CHO + O 2 Actually 6CO 2 + 6 H 2 O C 6 H 12 O 6 + 6O 2 carbon dioxide water glucose oxygen Light B I O L O G Y 0 2 3 30-Dec-09 Gardiner 15 RUBISCO Reaction • Melvin Calvin and Andy Benson discovered the pathway for glucose biosynthesis. • Reactions occur in the chloroplast stroma. • Experiment: Followed the incorporation of radioactive CO 2 into biological molecules • 3-phosphoglycerate is the first, stable intermediate • Precursor is RuBP, ribulose-1,5- bisphosphate.
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 4
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 7

Week 2, Lecture 3, Photosynthesis - Free Food Chemiosmosis...

This preview shows document pages 1 - 4. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online