Class Notes (808,754)
United States (313,251)
NSCI 1413 (15)
Lecture 5

NSCI 1413 Lecture 5: Photosynthesis

3 Pages
Unlock Document

Fordham University
Natural Science
NSCI 1413
Guy Robinson

Equation: 6CO​2​ 12H​2​ + Light → C6​H12​6​+ 62​ O + 62​ ● Two main processes: ○ Light-Dependent Reactions:​ Use light energy to produce the ATP that powers LIR ○ Light-Independent Reactions:​ Calvin Cycle ○ **Light must be present for both processes to occur** Photosynthetic Pigments ● Absorb light energy of varying wavelengths to perform photosynthesis ● Two main groups: ▢​​Antenna Pigments:​ Absorb photons and pass to chlorophyll α ▪​ Chlorophyll ​β​:​ Green; absorb all wavelengths of light in red, blue, and violet range ▪ ​Cartenoids:​ Yellow, orange, and red; absorb in blue, green, and violet range ▴ ​Xanthophyll:​ Cartenoid with slight chemical variation ▪ ​Phycobilins:​ Reddish; absorb light in blue and green range ▢ Chlorophyll α:​ Take photons from antenna pigments to directly participate in light rxns; contains double bonds that provide electrons to flow through ETC during photosynthesis Chloroplast ● Grana:​ Location of light reactions; layers of membranes (thylakoids) are site of photosystems I and II ● Stroma:​ Location of light-independent reactions ● Enclosed within double membrane Photosystems ● Hundreds of light-harvesting complexes in thylakoid membranes ● Each contains a rxn center with chlorophyll α and a region with hundreds of antenna pigments that fuel chlorophyll α ● Photosystem II (P680) → Photosystem I (P700) Light-Dependent Reactions ● Light is absorbed and transferred through photosystems via ETCs with two routes ● Noncyclic Photophosphorylation:​ electrons enter 2 ETCs, forming ATP and NADH beginning with PII ○ Photosystem II (P680):​ Electrons from doubles bonds in chlorophyll α head are energized and moved to a higher energy level and captured by a ​primary electron acceptor (PEA) +​ -​ ○ Photolysis:​ Water is split, providing 2 electrons (lost to chlorophyll α in PII). 2 H​ , and 1 O​ ; oxygen released as waste ○ Electron Transport Chain:​ PII electrons pass along ETC via plastoquinone​ (2 cytochromes + proteins), ending in PI; 1 exergonic electron flow provides energy for chemiosmosis ○ Chemiosmosis:​ ATP formed via diffusion of protons through ATP synthase after being forced into stroma; energy produced is used in the Calvin Cycle ○ NADP:​ Becomes reduced after gaining 2 H​ from PII; carries H​ to Calvin Cycle to make sugar ○ Photosystem I (P700)​: Energy is absorbed; e​ s from chlorophyll α head are energized and captured by PEA (similar -​ -​
More Less

Related notes for NSCI 1413

Log In


Don't have an account?

Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.