Unit 3 5A: Photosynthesis Flashcards
Autotrophs
An organism which synthesizes its own organic materials (food), by capturing light energy and taking in inorganic compounds from its physical environment, to meets its energy needs
Heterotrophs
An organism which ingests organic materials by feeding on autotrophs or on other organisms and their products, in order to convert energy in to the form of energy stored in ATP
Photosynthesis
A chemical reaction in which light energy is used to convert the inorganic compounds carbon dioxide and water into the organic compound glucose; occurs in the chloroplast
ATP
The main immediate source of chemical energy within a cell, powering most cellular processes, when a phosphate group is removed, energy is released and ADP is formed
Cellular respiration
A chemical reaction in which the organic compounds glucose is broken down, producing various products (depending on presence or absence of oxygen) and energy in the form of ATP
What type of chemical reaction is photosynthesis
Photosynthesis is an anabolic chemical reaction
Chlorophyll
the green pigments on the thlylakoid membrain of the chloroplasts; absorbs light energy for photosynthesis
What is the word equation for photosynthesis?
carbon dioxide + water –(Light energy, chloroplast)->
Oxygen+water+glucose
Chlorophyll
The green pigment on the thylakoid membranes of the chloroplasts of green plants; Absorbs light energy for photosynthesis
Granum
(Plural grana) a stack of thylakoid membranes inside the chloroplast of plant and algae cells
Thylakoid membrane
Disc-shaped interconnected membrane-bound compartments inside a chloroplast that make up the grana and are the location of the pigment chlorophyll, and therefore the site of the light-dependent stage of photosynthesis.
Stroma
The gel-like fluid inside a chloroplast which surrounds the grana; site of the light-independent stage of photosynthesis.
Light-dependent stage
The first stage of photosynthesis; occurs in the thylakoid membranes and involves the splitting of water using light energy
Light independent stage
The second stage of photosynthesis; occurs in the stroma of the chloroplast and involves the use of carbon dioxide to create glucose; also called the Calvin Cyle or Carbon Fixation
Photolysis
The splitting of water using the light energy from the sun
ADP (Adenine diphosphate)
A compound composed of adenosine and 2 phosphate groups that can store energy when another inorganic phosphate group is added, forming ATP
NADP+
a coenzyme that accepts and transfers hydrogen ions from one place to another during photosynthesis
Coenzyme
An organic molecule that contains carbon and binds to enzymes to help them to function; examples are NADP NAD and FAD
RuBP
Ribose biphosphate, a 5C (5 carbon) compound that combines with carbon dioxide at the start of the Calvin Cycle of photosynthesis to form PGA
Rubisco
RuBP Carboxylase, an enzyme that catalyses the formation of PGA by fixing carbon dioxide to RuBP during the Calvin Cycle of photosynthesis
Both Carbon dioxide and oxygen can both act as substrates which bind to the active site of rubisco
Has quaternary structure
PGA
3-phosphoglycerate, a 3C (3 Carbon) compound formed when the enzyme Rubisco catalyses the attachment of a carbon from carbon dioxide to RuBP during the Calvin Cycle of photosynthesis
PGAL
glyceraldehyde-3-phosphate, a 3C sugar that leads to the formation of glucose and regenerates RuBP in the process to continue the Calvin Cycle
Light energy is converted into what form of energy during photosynthesis?
Chemical energy
Name the collective term for the plant pigments that help chlorophyll harness light energy
Carotenoids
Which two colours of the visible light spectrum are primarily absorbed by chlorophyll a and b?
Red and blue
What is the waste product of photosynthesis
Oxygen
Where does the Calvin Cycle take place?
The stroma
Name the stage of photosynthesis where carbon dioxide is used
Light independent stage
Name the enzyme that catalyses the formation of PGA
Rubisco
Steps in te light dependent stage
- When light energy is captured, it splits water (photolysis), producing oxygen (O2),
hydrogen ions (H+) and electrons. - The oxygen is released, by diffusion, out of the thylakoid membrane to the stroma, into the atmosphere as a waste product of photosynthesis
- Electrons released when light energy stimulates chlorophyll are used by ATP
synthase, an enzyme embedded in the thylakoid membrane, to catalyse the
synthesis of ATP from ADP and Pi (inorganic phosphate). - Hydrogen ions (also called protons) and some of the electrons released in the
previous step are taken up by an acceptor molecule called NADP+, which then forms NADPH. - The hydrogen ions (via NADPH) and ATP produced during the light-dependent stage
of photosynthesis are then transported to the stroma for the light-independent
stage of photosynthesis.
