Cambridge A Levels A2 Biology Chapter 13 Photosynthesis
8 views 0 purchase
Course
Cambridge A Levels A2 Biology
Institution
Chapter 13 Photosynthesis: 26 pages
Sick of reading textbooks full of nonsense and gibberish? Hard to study with your teacher's notes? Lazy to do your own notes? Can't find any online notes that are extensive enough and always leave out something from the syllabus? Look no further !!
This set...
Chapter 13 Photosynthesis
13.1 Photosynthesis as an Energy Transfer Process
13.2 Investigation of Limiting Factors
13.1 Photosynthesis as an Energy Transfer Process
General Equation of Photosynthesis
Photosynthesis involves:
• The trapping of light energy by photosynthetic pigments resulting in the synthesis of ATP
and reduced NADP which is then used to reduce CO2 to form carbohydrate.
• Taking in carbon dioxide and reducing it by adding hydrogen to it to produce
carbohydrate.
The hydrogen for this process comes from water.
The energy that drives the reactions comes from light, which is absorbed by a
green pigment called chlorophyll.
• Oxygen is a waste product of photosynthesis.
It may be lost from the cells, or it may be used in respiration.
Two Main Stages of Photosynthesis:
1. Light Dependent Stage
2. Light-Independent Stage
,Structure and Function of Chloroplasts
Structure
• Has a biconvex shape.
• Has a diameter of 4-10µm.
• Surrounded by two membranes (the chloroplast envelope).
• Stroma:
• A fluid-filled region.
• Stroma consists of a membrane system which consists of thylakoids.
Thylakoid, Grana, Lamella:
• Thylakoids are membrane bound flattened fluid-filled vesicles.
• Stacks of thylakoid form grana which are connected by intergranal lamella.
• The membrane of the grana provides a large surface area which consists of
photosystems which in turn contain photosynthetic pigments, electron carrier
molecules as well as enzymes (ATP synthase).
These are needed for the light-dependent reactions.
• The thylakoid space is fluid-filled and is the site of photolysis of water.
• Stroma contains energy stores in the form of starch grains and lipid droplets.
• Stroma contains 70s ribosomes, circular DNA and enzyme that catalyse the chemical
reactions in the Calvin cycle, the light independent reactions.
, Adaptations of Leaves as a Photosynthetic Organ
• They provide a large surface area over which light can be reabsorbed.
• They are thin, providing a short diffusion pathway for the gases O2 and CO2.
• The midrib and extensive network of veins provide a good support for the thin
lamina/blade.
• The veins consist of xylem and phloem tissue which transport water and minerals to the
leaf cells and sucrose away from the leaves respectively.
• The mesophyll tissue in the leaf has a large number of chloroplasts that contain
chlorophyll which can absorb light energy.
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 or Stuvia-credit 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 lam1. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $2.99. You're not tied to anything after your purchase.
