Chapter 8 Flashcards
Write the general equations of photosynthesis
Plants, Algae, and Photosynthetic Bacteria: CO2 + 2 H2A + Light energy -> CH2O + A2 + H2O
Plants and Algae: CO2 + 2 H2O + Light energy -> CH2O + O2 + H2O
Carbohydrate produced is glucose: 6 CO2 + 12 H2O + Light Energy -> C6H12O6 + 6 O2 + 6 H2O
Describe the general structure of chlorosplasts
Chloroplasts - a semiautonomous organelle found in plant and algal cells that carries out photosynthesis
Chloroplasts have an outer membrane, intermembrane, inner membrane (inside the chloroplasts: Granum, which is made of thylakoid membranes = thylakoid lumen), the stroma is the fluid-filled area surrounding the thylakoid membranes and encased by the inner membrane
Compare and contrast the two phases of photosynthesis: the light reactions and the Calvin Cycle
Light reactions require light, while the Calvin cycle does not
Light reactions occur in the thylakoids, while the Calvin cycle occurs in the stroma
Light reactions produce ATP and NADPH, while the Calvin cycle uses ATP and NADPH to produce sugars
Light reactions produce oxygen, while the Calvin cycle uses carbon dioxide
Howeverrr, these both rely on each other to produce sugars and other organic molecules.
Describe the general properties of light
Light is a form of electromagnetic radiation
essential to support life on Earth
Electromagnetic radiation travels as waves caused by the oscillation of the electric and magnetic fields
Light has properties that are characteristic of particles - light is composed of discrete particles called photons (each photon contains a specific amount of energy)
Light travels in a straight line and is a form of energy (can be transformed into chemical energy - photosynthesis)
Identify where in the cell the light reactions take place
Light reactions occur in the thylakoid membranes of chloroplasts
Explain how pigments absorb light energy and list the types of pigments found in plants and green algae
Pigments absorb light by exciting the electrons in their molecules or solids to higher energy levels. Some wavelengths of light energy are absorbed and others are reflected
Leaves look green because they reflect light energy with wavelengths in the green region of the visible spectrum
Chlorophyll a and chlorophyll b are the pigments found in green plants and algae
Outline the steps in which photosystems 2 and 1 capture light energy and produce O2, ATP, and NADPH
Photosystem 2 happens first: light excited electrons in pigment molecules within the light-harvesting complex of PSII; oxidizes water, generating O2 and H+; electrons exit PSII and enter electron transport chain; energy used to make H+ electrochemical gradient
Photosystem I happens second: primary role to make NADPH; light hits light-harvesting complex of PSI; High energy electron is removed from pigment molecule and transferred to a primary electron acceptor; electrons transferred to NADP+ which also accepts an H+ to produce NADPH
Describe the process of ATP production in photosynthesis
Photophosphorylation: using the energy of the sunlight to form ATP from the phosphorylation of ADP
produced in stroma by ATP synthase using the H+ electrochemical gradient
Outline the three phases of the Calvin Cycle
Phase 1: Carbon Fixation; CO2 incorporated into RuBP using rubisco (RuBP carboxylase/oxygenase); Reaction product is a six-carbon intermediate that splits into two 3-phosphoglycerate molecules (3PG)
Phase 2: Reduction and Carbohydrate production; ATP is used to convert 3PG into 1,3-bisphosphoglycerate (1,3-BPG); NADPH electrons reduce it to glyceraldehyde-3-phosphate (G3P); 6 CO2 -> 12 G3P; only 2 G3P molecules used for carbohydrates and 10 are used for regeneration of RuBP
Phase 3: Regeneration of RuBP; 10 G3P are converted into 6 RuBP using 6 ATP
Calvin cycle begins by using carbon from an inorganic source and ends with organic molecules that will be used to make other molecules
Identify where in the cell the Calvin cycle reactions take place
the stroma of the chloroplast
Photosynthesis
The process whereby light energy is captured by plant, algal, or photosynthetic bacterial cells and is used to synthesize molecules from CO2 and H2O (or H2S)
Chloroplast and chlorophyll
Chloroplast: a semiautonomous organelle found in plant and algal cells that carries out photosynthesis
Chlorophyll: a photosynthetic green pigment found in the chloroplasts of plants, algae, and some bacteria
Thylakoid membrane
A membrane with the chloroplast that forms many flattened, fluid-filled tubules that enclose a single, convoluted compartment. The membrane contains chlorophyll and is the site where the light-dependent reactions of photosynthesis occurs
Grana
AKA Granum: a structure composed of stacked membrane-bound thylakoids within a chloroplast
Lumen
The fluid-filled compartment within a thylakoid
Stroma
The fluid-filled region of the chloroplast between a thylakoid membrane and the inner membrane
Calvin Cycle: Light-independent reaction (dark reaction)
A set of reactions that occur during photosynthesis and carbon fixation to convert carbon dioxide into glucose
Calvin Cycle: Ribulose-1, 5- biphosphate (RuBp)
the molecule that starts the cycle
Calvin Cycle: Rubisco (Ribulose- 1, 5 - biphosphate carboxylase)
Rubisco is an enzyme that catalyzes the first major step of carbon fixation in the calvin cycle during photosynthesis.
Calvin Cycle: Fixation
This is the first step (carbon fixation) that reduces CO2. The CO2 binds to RuBP in the process of carbon fixation