Grade 10 Biology: Photosynthesis Exam Flashcards

Photosynthesis Concepts

• Stromata: Pores in plant leaves that allow for the exchange of gases, letting CO2 enter and O2 exit.
• Heterotroph: Organisms that obtain energy by consuming other organisms, rather than producing it themselves.
• Autotroph: Organisms like plants that produce their own food through photosynthesis.
• Photosystems: Complexes within thylakoid membranes that organize chlorophyll and pigments to capture light energy.
• NADP+: An electron carrier that accepts high-energy electrons and becomes NADPH, crucial for energy transformation during photosynthesis.
• Pigments: Light-absorbing molecules in plants that capture sunlight's energy.

Structures Involved in Photosynthesis

• Stroma: Fluid-filled region surrounding thylakoids where the Calvin Cycle takes place.
• Thylakoids: Membrane-bound sacs organized in stacks (grana) where light-dependent reactions occur.

Photosynthesis Process

• Photosynthesis: The process wherein plants convert sunlight, water, and carbon dioxide into glucose and oxygen.
• Light-dependent Reactions: Utilize solar energy to create ATP and NADPH.
• Calvin Cycle: Utilizes ATP and NADPH to convert CO2 into high-energy carbohydrates.

Calvin Cycle Steps

• Step 1: Carbon fixation where CO2 combines with a 5-carbon molecule, resulting in 2 C3 molecules.
• Step 2: ATP energy is provided to the C3 molecules, producing ADP and releasing Pi groups.
• Step 3: NADPH transfers hydrogens, forming 2 molecules of PGAL and yielding more energy for C3.
• Step 4: Removal of PGAL molecules for conversion into glucose or other essential compounds.
• Step 5: Remaining carbon compounds processed to regenerate 5-carbon molecules for the cycle's continuation.

Light Spectrum and Plant Growth

• Best Spectrum: White light is optimal for plant growth.
• Other Effective Colors: Blue is the best followed by red, violet, and orange.
• Worst Spectrum: Green light is least effective for plant growth.

Chemical Requirements and Products

• Requirements for Photosynthesis: Sunlight, water, and CO2 are essential.
• Photosynthesis Equation: sunlight + H2O + CO2 → C6H12O6 + O2.
• Products: Include ATP, NADPH, and oxygen.

Theories and Experiments

• Van Helmont's Experiment: Demonstrated that soil primarily provides water to plants, stressing its role in supporting growth.
• Joseph Priestly's Discovery: Showed that plants release oxygen, confirming the role of plants in generating breathable air.

Miscellaneous Facts

• Reactants of Calvin Cycle: ATP, CO2, and NADPH are needed for the fixation process.
• Products of Calvin Cycle: High-energy sugars, along with ADP and NADP+.
• Evolutionary Context: Plants are said to have evolved further than humans, which reflects their adaptability.
• Chemical Communication: Plants can communicate through chemical signals to respond to environmental changes.
• Impact of Darwin: His theories significantly changed the field of biology, particularly our understanding of evolution.

Electron Transport and Energy Production

• NADP Reductase: Last enzyme facilitating the transfer of electrons, producing NADPH for the Calvin cycle.
• NADPH Production: Generated through the interaction of re-energized electrons from photosystem I with the NADP+ carrier.

True/False Insights

• Plants exhibit movement towards light and can obtain nutrients from dead insects (Sundew plants).
• Sunflowers rely on bees for pollination, confirming their symbiotic relationship with other organisms.

These notes encapsulate the major concepts regarding photosynthesis, related structures, and historical contributions, ideal for exam preparation.

Test your knowledge of key terms related to photosynthesis with these flashcards. Each card provides a definition to important concepts such as stromata, heterotrophs, and ATP synthase. Perfect for Grade 10 biology students looking to improve their understanding of plant processes.