How to Learn photosynthesis:
Photosynthesis is often seen as a difficult topic, but you can make perfect sense of it all if you approach it in the right way.
1. Know where Photosynthesis takes place. Learn the structure and function of the chloroplast - the sites of photosynthesis and know that the light dependent reactions take place in the thylakoid membranes, and the Calvin cycle (the light independent reactions) take place in the stroma.
2. You need an overview of photosynthesis. A good overview provides you with a framework onto which you can hang the details.
3. 'Actively' watch the video lessons on the Light dependent stages of photosynthesis in full as many times as needed and work through the knowledge check PDF that accompanies the lesson.
4. "Activly' watch the video lesson on the Calvin cycle - the light independent stages of photosynthesis in full as many times as needed and work through the knowledge check PDF that accompanies the lesson.
5. Repeat - Making your own diagrams, posters and revision notes. work through the knowledge check PDF's again making sure you can write well structured answers to the questions.
Photosynthesis can be divided into two easy steps.
The Light dependent reaction and the Light independent reactions (the Calvin Cycle).
What does it mean to "Actively" watch a lesson?
It simply means you need to watch the videos and take action! i.e. Don't be a 'passive' learner! just watching a lesson won't be much use. You need to download the PDFs that accompany the lessons, make your own notes, create your own posters and diagrams... write your own answers to the questions... All the while, using the video and PDF to guide your learning, watching in full as many times as needed. Pause and rewind and actively engage. write down definitions and new terminology... use the learning outcomes to keep you on track. by spending some quality time, actively engaging in lessons you'll soon learn the concepts and be able to apply your knowledge - and if you need a recap, repeat the learning process to really embed the topics and biological concepts.
A Level Biology -
The Chloroplast - The site of Photosynthesis.
Chloroplasts are the organelles that house all the enzymes and other substances needed for photosynthesis.
A Level Biology -
An Overview of Photosynthesis.
The light-dependent reactions:
Light hits chlorophyll, which emits two high-energy electrons. These electrons are used, via a series of electron transfer reactions, to make ATP and NADPH. Replacement electrons for chlorophyll are provided when water is split, a process that also produces oxygen as a by-product.
The light-independent reactions (the Calvin Cycle)
ATP and NADPH are used, via a series of reactions known as the Calvin Cycle, to reduce carbon dioxide into glucose.
A Level Biology - Photosynthesis:
The Light Dependent Reactions of Photosynthesis
The light-dependent reactions
The light-dependent reactions take place on the thylakoids, where the chlorophyll molecules are housed
When a photon of light hits a molecule of chlorophyll, the pigment becomes excited and emits two high-energy electrons.
These electrons pass down an electron transport system that synthesises ATP – this is called photophosphorylation
Energy from the excited electrons is also used to split water; this is photolysis and produces electrons to replace those lost by the chlorophyll, protons (H+ions) and oxygen as a by product
Electrons are used to make NADPH (reduced NADP).
ATP and NADPH are essential for the light independent reaction, and oxygen is released into the atmosphere.
A Level Biology - Photosynthesis: The Calvin Cycle -
The Light Independent Reactions of Photosynthesis