Photosynthesis

Question 1

Electromagnetic Radiation

Answer 1

• occurs in individual packets of energy: photons
• photons with short wavelengths (high frequency) have high energy, long wavelengths (low frequency) have low energy
• solar energy captured by producers and stored as chemical energy in the bonds of glucose moleculesq

Question 2

Summarized Photosynthesis Formula

Answer 2

CO₂ + H₂0 + energy → C₆H₁₂O₆ + O₂
carbon dioxide + water + energy → glucose + oxygen
- includes only compounds at the start and end of the reaction

Question 3

Chlorophyll

Answer 3

• light-absorbing green pigment
• chlorophyll a (blue-green), the primary light-absorbing pigment which transfers energy for photosynthesis reactions
• chlorophyll b (yellow-green), an accesory pigment which absorbs other wavelengths and transfers them to chlorogpyll a
• absorbs photons in blue-violet (400 - 500 nm) and red (600 - 700 nm) regions of the spectrum

Question 4

Chloroplasts

Answer 4

• distinct organelle of leaf cells where chlorophyll is stored
• has two membranes (inner and outer)
• filled with protein-rich semiliquid called stroma
• membrane-bound sacs are stacked within the stroma called thylakoids
• each column of thylakoids is called a granum
• unstacked thylakoids connect adjacent grana called lamellae
• each chloroplast contains 60 grana with 30 - 50 thylakoids each

Question 5

Thylakoid

Answer 5

• membrane contains light-gathering pigments
• filled with water called thylakoid lumen
• are stacked and pancake shaped to increase surface area and effeciency of photosynthesis

Question 6

ATP

Answer 6

• energy-supply molecule for cellular functions
• provides immidiate energy for cellular processes
• releases energy when split into ADP and Pi

Question 7

NADPH

Answer 7

• electron donor
• donates two electrons and a hydrogen ion to another molecules to become NADP⁺

Question 8

3 basic stages of photosynthesis

Answer 8

1. capturing solar energy and transfering it to electrons
2. using energized electrons to produce ATP and NADPH
3. using ATP and NADPH to form glucose from CO₂

Question 9

Light-depedent reactions

Answer 9

• stages one and two of photosynthesis
• occurs in the thylakoid membrane
• requires photons as a reactant
• sythesizes ATP and reduces NADP⁺ into NADPH

Question 10

Light-independent reactions

Answer 10

• last stage of photosynthesis
• occurs in the stroma
• does not need photons as a reactant but depends on molecules from LDR to function
• a cyclic sequence of enzyme-catalylized reactions to turn CO₂ into glucose

Question 11

LDR input, output

Answer 11

light + H₂0 → ATP + NADPH

Question 12

LIR input, output

Answer 12

ATP + NADPH + CO₂ → ATP + Pi + NADP⁺ + C₆H₁₂O₆

Question 13

Redox Reactions

Question 14

Chemiosmosis

Answer 14

• high concentration of H⁺ causes a positive charge in the lumen
• H⁺ escape the thylakoid through protein complexes in the membrane called ATP sythase complexes
• energy released by passing H⁺ drives enzymes to combine ADP and Pi into ATP