a. Autotrophs capture free energy from physical sources in the environment.
Evidence of student learning is a demonstrated understanding of each of the following:
1. Photosynthetic organisms capture free energy present in sunlight.
2. Chemosynthetic organisms capture free energy from small inorganic molecules present in their environment, and this process can occur in the absence of oxygen.
c. Different energy-capturing processes use different types of electron acceptors.
To foster student understanding of this concept, instructors can choose an illustrative example such as:
• NADP+ in photosynthesis
• Oxygen in cellular respiration
d. The light-dependent reactions of photosynthesis in eukaryotes involve a series of coordinated reaction pathways that capture free energy present in light to yield ATP and NADPH, which power the production of organic molecules.
Evidence of student learning is a demonstrated understanding of each
of the following:
1. During photosynthesis, chlorophylls absorb free energy from light, boosting electrons to a higher energy level in Photosystems I and II.
2. Photosystems I and II are embedded in the internal membranes of chloroplasts (thylakoids) and are connected by the transfer of higher free energy electrons through an electron transport chain (ETC). [See also 4.A.2]
3. When electrons are transferred between molecules in a sequence of reactions as they pass through the ETC, an electrochemical gradient of hydrogen ions (protons) across the thykaloid membrane is established.
4. The formation of the proton gradient is a separate process, but it is linked to the synthesis of ATP from ADP and inorganic phosphate via ATP synthase.
5. The energy captured in the light reactions as ATP and NADPH powers the production of carbohydrates from carbon dioxide in the Calvin cycle, which occurs in the stroma of the chloroplast.
✘✘Memorization of the steps in the Calvin cycle, the structure of the molecules and the names of enzymes (with the exception of ATP synthase) are beyond the scope of the course and the AP Exam.
e. Photosynthesis first evolved in prokaryotic organisms; scientific evidence supports that prokaryotic (bacterial) photosynthesis was responsible for the production of an oxygenated atmosphere; prokaryotic photosynthetic pathways were the foundation of eukaryotic photosynthesis.
h. Free energy becomes available for metabolism by the conversion of
ATP→ADP, which is coupled to many steps in metabolic pathways.
LO 2.4 The student is able to use representations to pose scientific
questions about what mechanisms and structural features allow
organisms to capture, store and use free energy. [See SP 1.4, 3.1]
LO 2.5 The student is able to construct explanations of the
mechanisms and structural features of cells that allow organisms to
capture, store or use free energy. [See SP 6.2]
Intro to pigments and the light reaction: computer simulation
Setting up a MW account: teachers ID % rapina
Objective: To create a 3D model of the light reaction in photosynthesis with an emphasis on electron movement.
- 8” X 11” colored paper
- Light Reaction Parts Sheet
- Paper Clips
1) Work in pairs to build a representation of the light reaction using the parts sheet provided.
2) Study for your upcoming verbal quiz; you will be able to use your model to explain the light reaction.
3) Each person is quizzed individually. If you earn a perfect score you may become a quizzer. You may miss 2 questions, if you miss a 3rd you need to go back to your model and questions to review the process before quizzing again.
Photosynthesis rap http://www.schooltube.com/video/dc732e59026d90ab949d/
Lessons from thin air
Photosynthesis media below