Compartmentalization and Photosynthesis 10/14

Metabolic Pathway

• A series of linked reactions.

Enzyme Cycle

• An enzyme pathway that does not have a specific end product.

Compartmentalization

• Division of a system into sections for specific functions.

• Assigns functions to organelles.

• Prokaryotes compartmentalize in different regions.

Feedback Inhibition

• The product inhibits its own enzyme by binding to an allosteric site.

• Inhibition decreases when the product is used up.

Metabolic Pathway Disease

• A mutation in a gene disrupts one enzyme in a pathway, preventing the formation of an end product.

Redox Reactions

• Oxidation-Reduction Reaction: Transfer of electrons from one molecule to another.

  • Oxidation: Loss of electrons.

  • Reduction: Gain of electrons.

Photosynthesis

• 

• Carbon dioxide + Water → Sugar + Oxygen

Stomata

• Openings in the leaves of plants.

  • CO₂ enters here and diffuses into the chloroplasts.

  • Water and oxygen leave.

• Stoma: Singular of stomata.

Autotrophs

• Organisms that produce their own food.

Heterotrophs

• Organisms that consume other organisms.

Factors Affecting Photosynthesis

• Increase to Point of Saturation:

  • Light, CO₂, Water

• Increase then Decrease:

  • Temperature

Chloroplasts

• Have two membranes: outer and inner.

Key Components:

• Stroma: The fluid solution inside the chloroplast.

• Thylakoid: Photosynthetic discs found within the chloroplast.

• Granum: A stack of thylakoids.

• Lumen: The liquid inside a thylakoid.

• Photosystem: A group of pigments and electron acceptor molecules within a thylakoid membrane, often referred to as the "solar power plant."

  • Two types: PSI (Photosystem I) and PSII (Photosystem II).

• Chlorophyll: A pigment found in the thylakoid membrane that absorbs light energy, giving plants their green color.