Biology: Hydrolysis, ATP, and Photosynthesis

Hydrolysis and Phosphorylation

• Hydrolysis is the process of breaking down bonds between phosphate groups.
• Phosphorylation is the addition of phosphate to an organic compound.

Adenosine Triphosphate (ATP)

• ATP is the energy currency of the cell.
• ATP is composed of adenine, ribose, and three phosphate groups.
• The breakdown of ATP releases energy for cellular processes.

Chromatography

• Chromatography is a technique for separating components in mixtures based on differences in structure or composition.

Pigments

• Pigments are substances that absorb visible light.
• Different pigments absorb different wavelengths of light.
• Photoexcitation is the production of an excited state in a quantum system by absorbing a photon.

Photosynthesis

• Photosystems are aggregates of pigments and proteins in the thylakoid membrane that absorb photons and transfer energy.
• Light-harvesting complexes (antenna complexes) absorb photons and transfer energy to a reaction center.
• Reaction-center complexes contain chlorophyll a and a primary electron acceptor.
• Photosystem II (P680) and Photosystem I (P700) are involved in light-dependent reactions.

Chlorophyll

• Chlorophyll is a green pigment found in thylakoid membranes of chloroplasts.
• Chlorophyll absorbs blue and red light while reflecting green light.

Other Plant Pigments

• Anthocyanins are responsible for the red/purple colors in fruits.
• Carotenoids are responsible for yellow/orange colors in fruits and vegetables.
• Xanthophylls are carotenoids with oxygen-containing groups

Cell Work

• Chemical work involves building large molecules.
• Mechanical work involves movement, like muscle contraction.
• Transport work involves moving substances across membranes against their concentration gradient.

Light and Dark Reactions in Photosynthesis

• Light reactions occur in the thylakoid membrane.
• They use sunlight to produce ATP and NADPH, and split water to release oxygen.
• Dark reactions (Calvin cycle) occur in the stroma.
• They use ATP and NADPH to convert carbon dioxide into glucose.

Cellular Respiration

• Cellular respiration is a metabolic process that converts chemical energy into ATP.
• Aerobic respiration requires oxygen and produces 34 ATP per glucose molecule.
• Glycolysis is the first step of respiration.
• It involves breaking down glucose into pyruvate.
• The Krebs cycle further oxidizes pyruvate to produce carbon dioxide, NADH and FADH2.
• The electron transport chain uses the energy from NADH and FADH2 to create ATP.
• Anaerobic respiration (fermentation) does not require oxygen and produces less ATP.

Similarities/Differences Between Photosynthesis and Respiration

• Both processes use electron transport chains to generate ATP.
• Photosynthesis takes in CO2, water and releases O2, and glucose(sugars).
• Respiration takes in O2, glucose and releases CO2, and water.