Photosynthesis Notes Essay

Submitted By Lindsey2Mae
Words: 531
Pages: 3


Pigment: light absorbing substance -Reflects color seen and absorbs other ones
Chlorophyll: primary pigment in chloroplasts of plants -absorbs blue & red, reflects green & yellow
Thylakoid: disk shaped structures in chloroplasts containing chlorophyll

Vocabulary: Molecules

ATP: adenosine tri-phosphate
-energy molecule of the cell
NADPH: electron carrier in cells
-Glucose: simple sugar made by plants in Calvin cycle (C6H12O6)

Stages of Photosynthesis

1: Pigments capture energy from sun
2: Light energy is converted to chemical energy (ATP and NADPH)
-Energy stored in chemical bonds
3: ATP, NADPH and CO2 used to make glucose

Stage 1: Photosystem 2

Thylakoid absorbs light
Light energy transferred to chlorophyll
H2O is split by an enzyme to make H+ and O2
H+ goes to the Calvin cycle, O2 is released (as the air we breathe)

Stage 2: Photosystem 1

Energy from sun is used to make ATP and NADPH (stored in bonds)
NADPH: electron carrier
Both ATP and NADPH store energy for later use (Calvin Cycle)

Stage 3: Calvin Cycle

1. RuBisCo bonds a CO2 to a 5C molecule making an unstable 6C
2. The unstable molecule denatures into two 3C molecules
3. 3C molecules are joined to make a stable glucose molecule

Factors Affecting Photosynthesis

Amount of light: more light, more photosynthesis
Amount of CO2 available
Temperature: reactions and enzymes like certain temp. ranges

Net Reaction

6CO2 + 6H2O → C6H12O6 + 6O2
Reactants: carbon dioxide, water, energy
Products: glucose, oxygen

Cell Respiration

Breakdown of glucose for usable energy in cells
Aerobic: with oxygen
Anaerobic: without energy

Net Reaction

Reverse of photosynthesis
ATP: adenosine tri-phosphate

Stages of Respiration

Aerobic respiration -Krebs cycle -Electron Transport Chain OR
Anaerobic Respiration -Lactic Acid or Alcohol


Breakdown of glucose in cytoplasm
Uses 2 ATP to break down glucose (6C) into 2 pyruvate molecules (3C)
Energy from breakdown of glucose produces 4 ATP
Net Yield of 2 ATP

Krebs Cycle: Aerobic

Occurs in mitochondria
Oxygen must be present
2 pyruvate…