Ch 5 Photosynthesis Flashcards
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
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 6 ATP.
substrate
The reactant of a reaction catalysed by an enzyme.
photorespiration
A wasteful process in plants initiated by Rubisco that limits photosynthesis.
stoma (pl. stomata)
A small pore on the leaf’s surface that opens and closes to regulate gas exchange.
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.
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.
stoma (pl. stomata)
A small pore on the leaf’s surface that opens and closes to regulate gas exchange.
photorespiration
A wasteful process in plants initiated by Rubisco that limits photosynthesis.
Rubisco
A pivotal enzyme involved in initial carbon fixation during the light-independent stage of photosynthesis.
affinity
The tendency of a molecule/atom to bind or react with another molecule/atom.
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.
Rubisco
A pivotal enzyme involved in initial carbon fixation during the light-independent stage of photosynthesis.
photorespiration
A wasteful process in plants initiated by Rubisco that limits photosynthesis.
C3 plants
Plants with no evolved adaptation to minimise photorespiration.
C4 plant
Plants that minimise photorespiration by separating initial carbon fixation and the remainder of the Calvin cycle over space.
CAM plant
Plants that minimise photorespiration by separating initial carbon fixation and the remainder of the Calvin cycle over time.
arable land
Land that is suitable for growing crops.
yield
The amount of agricultural product harvested per area of land.
