Plant definitions

ATP

adenosine tri-phosphate - nucleotide found in all living organisms produced during respiration and is important in the transfer of energy

stalked granules

ATP synthase channels on thylakoid and inner mitochondria membrane

photoionization

chlorophyll molecules are oxidized (ionised) by pair of electrons leaving by being excited by photons of light

electron carriers

proteins that form a chain in thylakoid membranes to transport excited electrons from chlorophyll to reduce NADP

chemiosmotic theory

ATP is generated as protons (H⁺) diffuse down their electrochemical gradient across a semipermeable membrane (the inner mitochondrial membrane/chloroplast thylakoid membrane) through ATP synthase enzyme

autotroph

organism that provides it’s own food

photoautotroph

organism that requires sunlight to produce it’s own food from inorganic substances

calvin cycle

biochemical pathway that forms part of the light-independent reaction of photosynthesis during which carbon dioxide is reduced to form carbohydrate

hydrogen bond

chemical bond formed between the partial positive charge on a hydrogen atom and the partial negative charge on another atom of an adjacent molecule

hydrolysis

breaking down of large molecules into smaller ones by the addition of water molecules

granum

stack of thylakoids in a chloroplast - the site of light dependent reaction of photosynthesis

krebs cycle

series of aerobic biochemical reactions in the matrix of the mitochondria of most eukaryotic cells by which energy is obtained through the oxidation of acetylcoenzyme A produced from the breakdown of glucose

light dependent reaction

stage of photosynthesis in which light energy is required to produce ATP and reduced NADP

light independent reaction

stage of photosynthesis which does not require light energy directly but does need the products of the light dependent reaction to reduce carbon dioxide and so form carbohydrate

limiting factor

variable that limits the rate of a chemical reaction

NADP

nicotinamide adenine dinucleotide phosphate - molecule that carries electrons produced in the light dependent reaction of photosynthesis

oxidation

chemical reaction involving the loss of electrons

reduction

chemical reaction involving the gain of electrons

oxidative phosphorylation

formation of ATP in the electron transport system of aerobic respiration

palisade cells

long narrow cells packed with chloroplasts that are found in the upper region of a leaf which carry out photosynthesis

pentose

sugar that has five carbon atoms

phloem

plant tissue that transports the products of photosynthesis from leaves to the rest of the plant

photolysis

splitting of a water molecule by light occurring during the light dependent reaction of photosynthesis (2H₂O → 4H⁺ + 4e^- + O₂)

stroma

matrix of chloroplast where the light independent reaction of photosynthesis takes place

substrate level phosphorylation

formation of ATP by the direct transfer of a phosphate group from a reactive intermediate to ADP

thylakoid

series of flattened membranous sacs in a chloroplast that contain chlorophyll and the associated molecules needed for the light dependent reaction of photosynthesis

yield

supply or produce of desired product