Topic 4:photosynthesis

C4 Plant

specialized plants that use the Hatch-Slack pathway to fix carbon dioxide (CO₂) into a four-carbon organic acid (oxaloacetate) before entering the standard Calvin cycle

Light capturing complexes

arrays of pigment-protein structures embedded in photosynthetic membranes like the thylakoids of plants, algae, and cyanobacteria

Light

electromagnetic radiation that can be perceived by the human eye, typically with wavelengths between 400 and 700 nanometers

Stomata

microscopic pores found in the epidermis of plant leaves, stems, and other green organs that control gas exchange and water regulation

NADPH

a critical coenzyme and reduced electron donor used in cellular metabolism, anabolic (building) reactions, and antioxidant defense systems.

ATP

the primary energy carrier in cells, produced during photosynthesis and cellular respiration, driving various biological processes.

Pigments

a finely ground, solid material that produces color by absorbing specific wavelengths of light and reflecting others.

Photons

discrete packets or quanta of light energy that are absorbed by pigments during photosynthesis to initiate the light-dependent reactions.

Grana

membrane-bound stacks of flattened disc-shaped sacs called thylakoids inside plant and algal chloroplasts.

Calvin Cycle

a series of biochemical redox reactions that take place in the stroma of chloroplasts in photosynthetic organisms.

Reduction

the act, process, or result of making something smaller, lower, or simpler in size, amount, degree, or complexity.

Mesophyll

the internal tissue layer of a plant leaf located between the upper and lower epidermal layers.

CAM Plant

use Crassulacean Acid Metabolism

G3P

a 3-carbon sugar phosphate that serves as a vital intermediate and direct product in both photosynthesis and cellular respiration

photorespiration

a metabolic side-reaction in plants where the enzyme RuBisCO attaches oxygen (O₂) instead of carbon dioxide (CO₂) to ribulose 1,5-bisphosphate (RuBP)

Photosynthesis

the biological process by which plants, algae, and cyanobacteria convert light energy from the sun into chemical energy to fuel their growth and metabolism.

Wavelength

The distance between consecutive, matching points on a wave.

Chloroplast

a specialized cell organelle found in plants and algae that converts sunlight into chemical energy through photosynthesis

redox reaction

any chemical process in which electrons are transferred between two species, causing changes in their oxidation numbers

oxidation

a chemical process in which an atom, ion, or molecule loses one or more electrons

Chlorophyll

natural green pigment in plants, algae, and cyanobacteria that absorbs sunlight to power photosynthesis.

Thylakoid

membrane-bound compartment inside plant chloroplasts, green algae, and cyanobacteria that serves as the site for the light-dependent reactions of photosynthesis

photosystems

large, multi-protein complexes found in the thylakoid membranes of plants, algae, and cyanobacteria that capture light energy and convert it into chemical energy.

heterotrophs

a living thing that cannot make its own food and must eat other plants, animals, or organic matter to get energy.

Photoprotection

any strategy or biochemical mechanism used to protect living organisms—especially skin—from the harmful effects of ultraviolet (UV), visible light, and solar radiation

Stroma

the supportive, structural, or fluid framework of an organ, tissue, or cell

reaction center

a specialized protein and pigment complex that turns light energy into chemical energy during photosynthesis

Kinetic Energy

the energy an object has because it is moving.