chapter 7 Flashcards
What are photosynthetic organisms?
Organisms that can produce their own food through photosynthesis
Examples include plants, algae, and some bacteria.
How do autotrophs produce their own food?
By converting light energy into chemical energy through photosynthesis
What are the components of a chloroplast?
Chlorophyll, thylakoids, stroma, and outer/inner membranes
What roles do oxygen and carbon dioxide play in autotrophs and heterotrophs?
Oxygen is a byproduct of photosynthesis; carbon dioxide is used in photosynthesis by autotrophs and produced by heterotrophs
What is the overall process of photosynthesis?
Conversion of light energy into chemical energy, producing glucose and oxygen from carbon dioxide and water
How does energy input compare to output in the light reaction?
Energy input comes from sunlight; output is stored as ATP and NADPH
What is compared in the carbon input and output of the Calvin cycle?
Input: carbon dioxide; Output: glucose and other carbohydrates
What is the relationship between wavelength and energy in the electromagnetic spectrum?
Shorter wavelengths have higher energy and longer wavelengths have lower energy
What is the role of photosynthetic pigments in harnessing solar energy?
They absorb light energy and convert it into chemical energy
How are ATP and NADPH produced?
Through redox reactions and membrane gradients during the light reactions
What are the three steps of the Calvin cycle?
Carbon fixation, reduction phase, and regeneration of RuBP
When are ATP and/or NADPH needed in the Calvin cycle?
ATP is needed for the regeneration of RuBP; NADPH is needed for the reduction phase
What is the significance of RuBP carboxylase enzyme to photosynthesis?
It catalyzes the first step of carbon fixation in the Calvin cycle
How is glyceraldehyde-3-phosphate (G3P) used in plants?
G3P is used to produce other necessary plant molecules, such as glucose and starch
Where does photosynthesis occur in C3 and C4 plants?
C3: mesophyll cells; C4: both mesophyll and bundle sheath cells
How do C3/C4 modes of photosynthesis contrast with CAM photosynthesis?
C3 and C4 occur during the day; CAM occurs at night to minimize water loss
How do different modes of photosynthesis help plants adapt to environments?
They allow plants to optimize water use, light capture, and carbon fixation based on environmental conditions
