Photosynthesis VCE 3/4

All Edolo definition for the biochemical pathway of photosynthesis.

photoautotroph

 an organism capable of undertaking photosynthesis

photosynthesis

the process of capturing light energy to power the production of glucose and oxygen from carbon dioxide and water

mesophyll cell

a plant cell type found in leaves that contain large amounts of chloroplasts

chloroplast

a membrane-bound organelle only found in plant and photoautotroph cells that is the site of photosynthesis

chlorophyll

a chemical found in the thylakoids of chloroplasts. It is responsible for absorbing light energy in photosynthesis

stoma (pl. stomata) 

 a small pore on the leaf’s surface that opens and closes to regulate gas exchange

xylem

vascular tissue in plants responsible for transporting water and minerals from the roots to the leaves

light-dependent stage

the first stage of photosynthesis, where light energy splits water molecules into oxygen and hydrogen inside the thylakoid membranes. Also known as the light-dependent reactions

thylakoid

a flattened sac-like structure housed inside the chloroplast. Each thylakoid is made up of a chlorophyll-containing membrane enclosing a lumen. Thylakoids are the location of the light-dependent stage of photosynthesis

granum (pl. grana)

a stack of thylakoids

NADPH

a coenzyme that is a proton (H+) and electron carrier in photosynthesis

ATP

adenosine triphosphate, a high energy molecule that, when broken down, provides energy for cellular processes

photolysis

s the process in which molecules are broken down by the action of light

light-independent stage

the second stage of photosynthesis where carbon dioxide is used to form glucose in the stroma of a chloroplast. Also known as the Calvin cycle, the dark stage, or the light-independent reactions

stroma

 the fluid substance that makes up the interior of chloroplasts. It is the site of the light-independent stage of photosynthesis

light-dependent stage

the first stage of photosynthesis, where light energy splits water molecules into oxygen and hydrogen inside the thylakoid membranes. Also known as the light-dependent reactions

light-independent stage

the second stage of photosynthesis where carbon dioxide is used to form glucose in the stroma of a chloroplast. Also known as the Calvin cycle, the dark stage, or the light-independent reactions

enzyme

an organic molecule, typically a protein, that catalyses (speeds up) specific reactions

Rubisco

a pivotal enzyme involved in initial carbon fixation during the light-independent stage of photosynthesis

carbon fixation

the process in living organisms where inorganic carbon, typically within carbon dioxide, is converted into organic compounds such as glucose. Carbon fixation is a central part of the light-independent stage of photosynthesis

inorganic

a compound that does not contain a carbon-hydrogen bond, e.g. carbon dioxide

organic

a compound containing a carbon-hydrogen bond, e.g. glucose

substrate

the reactant of a reaction catalysed by an enzyme

photorespiration

a wasteful process in plants initiated by Rubisco that limits photosynthesis

affinity

the tendency of a molecule/atom to bind or react with another molecule/atom

C3 plants

plants with no evolved adaptation to minimise photorespiration

mesophyll cell

a plant cell type found in leaves that contain large amounts of chloroplasts

C4 plants

plants that minimise photorespiration by separating initial carbon fixation and the remainder of the Calvin cycle over space

bundle-sheath cell 

a plant cell type that is the site of most of the Calvin cycle in C4 plants

CAM plants

plants that minimise photorespiration by separating initial carbon fixation and the remainder of the Calvin cycle over time

rate

the speed at which a chemical reaction proceeds

plateau

to reach a state where no further change occurs

enzyme

an organic molecule, typically a protein, that catalyses (speeds up) specific reactions

saturation point

the point at which a substance (e.g. an enzyme) cannot receive more of another substance (e.g. a substrate)

limiting factor

a factor that prevents the rate of reaction from increasing

limiting reagent

a reactant that prevents the rate of reaction from increasing

C3 plants

plants with no evolved adaptation to minimise photorespiration

C4 plants

plants that minimise photorespiration by separating initial carbon fixation and the remainder of the Calvin cycle over space

CAM plants

plants that minimise photorespiration by separating initial carbon fixation and the remainder of the Calvin cycle over time

optimal

the point at which for a given condition (e.g. temperature), the maximum function of an enzyme occurs. Also known as optimum

denature

the disruption of a molecule’s structure by an external factor such as heat

enzyme inhibitor

a molecule that binds to and prevents an enzyme from functioning

competitive inhibitor

a molecule that hinders an enzyme by blocking the active site and preventing the substrate from binding

non-competitive inhibitor

a molecule that hinders an enzyme by binding to an allosteric site and changing the shape of the active site to prevent the substrate from binding

allosteric site

a region on an enzyme that is not the active site

reversible inhibition

enzyme inhibition that involves weaker bonds that can be overcome

irreversible inhibition

enzyme inhibition that involves stronger bonds that cannot be broken

CRISPR

short, clustered repeats of DNA found in prokaryotes which protects them against viral invasion

CRISPR-associated protein 9 (Cas9)

an endonuclease that creates a blunt end cut at a site specified by guide RNA (gRNA)

genetic modification

the manipulation of an organism’s genetic material using biotechnology

genetically modified organism (GMO)

an organism with genetic material that has been altered using genetic engineering technology

arable land

 land that is suitable for growing crops

yield

the amount of agricultural product harvested per area of land