Lecture notes
2. Photosynthesis
- Module
- Biology 1B
- Institution
- University Of Glasgow
Notes taken from lecture slides and lecturers as well as the textbook. Notes will help with the photosynthesis topic within Biology 1B
[Show more]
Content preview
Photosynthesis• ATP – source of energy
• NADPH – source of reduction
• Light reaction – on or in the thylakoid membrane
• Dark reaction – in the stroma
On the outside of the thylakoids, molecules of NADP+ and ADP pick up electrons and phosphates,
respectively, and NADPH and ATP are the released to the stroma, where they play crucial roles in the
Calvin cycle.
Light reaction
The light reactions are the steps of photosynthesis that convert solar energy to chemical. Water is
split, providing a source of electrons and protons (hydrogen ions, H+) and giving off O2 as a by-
product. Light absorbed by chlorophyll drives a transfer of the electrons and hydrogen ions from
water to an accepter called NADP+, where they are temporarily stored. The light reactions use solar
energy to reduce to NADP+ to NADPH by adding a pair of electrons along with an H+. The light
reaction also generates ATP using chemiosmosis to power the addition of a phosphate group to ADP,
a process called photophosphorylation. Thus, light energy in the form of two compounds: NADPH
and ATP. NADPH, a source of electrons, acts as ‘reducing power’ that can be passed along to an
electron acceptor, reducing it, while ATP is the versatile energy currency of cells.
Chlorophyll and Carotenoids
• Chlorophylls - usually most abundant and most important pigments in
light harvesting. Contain tetrapyrrole ring (chlorin) similar to heme but
contains Mg2+. Chlorophylls a (Chl a) and b (Chl b) in plants
• Bacteriochlorophylls a (BChl a) and b (BChl b) are major pigments in
anaerobic photosynthetic bacteria.
• There is a Division of Labor Between the Chlorophyll Molecules - Light
can be captured by antenna pigments (green) and transferred among
themselves until reaching the reaction centers -------→
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller BiologyStudent. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for £5.49. You're not tied to anything after your purchase.
Can Stuvia be trusted?
4.6 stars on Google & Trustpilot (+1000 reviews)
75323 documents were sold in the last 30 days
Founded in 2010, the go-to place to buy revision notes and other study material for 14 years now