C1.3 Photosynthesis Notes

Photosynthesis

The process by which plants, algae, and some bacteria convert light energy from the sun into chemical energy stored in organic compounds like glucose.

Light-Dependent Reactions

These reactions capture light energy and convert it into chemical energy in the form of ATP and reduced NADP.

Light-Independent Reactions (Calvin Cycle)

This stage uses ATP and reduced NADP to fix carbon dioxide into glucose and other organic molecules.

Photolysis

The process of using light energy to split water molecules into oxygen, protons, and electrons.

Chlorophyll

A green pigment found in plants that absorbs light energy for photosynthesis.

Carbon Dioxide (CO₂)

A colorless gas absorbed by plants during photosynthesis.

Glucose

A simple sugar that is produced by photosynthesis and serves as an energy source for plants and other organisms.

ATP (Adenosine Triphosphate)

An energy carrier produced during the light-dependent reactions of photosynthesis.

NADPH

A reducing agent produced during the light-dependent reactions of photosynthesis, used in the Calvin cycle.

Stroma

The fluid-filled space surrounding the thylakoids in chloroplasts where the light-independent reactions occur.

Thylakoids

Disc-shaped structures within chloroplasts that contain photosynthetic pigments and are the site of light-dependent reactions.

Antenna Complex

A collection of pigments that absorb light and transfer energy to the reaction center in a photosystem.

Reaction Center

A specialized pair of chlorophyll molecules in a photosystem that releases excited electrons to an electron transport chain.

Light Absorption

The process by which pigments absorb photons of light, energizing electrons.

Proton Gradient

The difference in proton concentration across a membrane that drives ATP synthesis during chemiosmosis.

Calvin Cycle

The process in photosynthesis that fixes carbon dioxide into organic molecules, requiring ATP and NADPH.

Rubisco

An enzyme that catalyzes the fixation of carbon dioxide in the Calvin cycle.

Glycerate 3-Phosphate (G3P)

A three-carbon compound formed in the Calvin cycle that is a precursor for glucose and other organic molecules.

Triose Phosphate (TP)

A three-carbon sugar that can be converted into glucose and used for synthesizing other biomolecules.

Chloroplasts

Organelles in plant cells where photosynthesis occurs.

RuBP (Ribulose Bisphosphate)

A five-carbon sugar that acts as the CO₂ acceptor in the Calvin cycle.

NADP+

The oxidized form of NADP that accepts electrons to form NADPH.

Oxygen (O₂)

A byproduct of photosynthesis that is released into the atmosphere.

Electron Transport Chain (ETC)

A series of proteins that transfer electrons, leading to the pumping of protons and the production of ATP.

Chemiosmosis

The movement of protons across a membrane to generate ATP.

Non-Cyclic Photophosphorylation

A pathway where electrons flow from water through both photosystems to produce ATP and NADPH.

Cyclic Photophosphorylation

A pathway where electrons from photosystem I are recycled to generate additional ATP without producing NADPH.

Ferredoxin

An iron-sulfur protein that plays a role in the electron transport chain of photosynthesis.

Carbon Fixation

The process of converting inorganic carbon dioxide (CO₂) into organic molecules during the Calvin cycle.

Amino Acids

Organic compounds that serve as the building blocks of proteins, synthesized using intermediates from the Calvin cycle.

Carbohydrates

Organic molecules made of sugar molecules that are a product of photosynthesis.

Lipids

Organic compounds used for energy storage, membranes, and signaling, synthesized from triose phosphate.

Photosystems

Complexes of proteins and pigments that absorb light energy for photosynthesis.

Energy Carriers

Molecules like ATP and NADPH that store energy for use in metabolic processes.

Stomata

Small openings on the surface of leaves that allow gases like carbon dioxide to enter and oxygen to exit.

Thylakoid Membranes

The internal membranes of chloroplasts that house the components for light-dependent reactions.

Surface Area

The area available for light absorption in thylakoids, increased by their stacked structure.

Organelles

Specialized structures within cells that perform specific functions, such as chloroplasts in photosynthesis.

Chlorophyll a

The primary pigment in plants that absorbs blue and red light.

Chlorophyll b

An accessory pigment that helps capture light energy for photosynthesis.

Carotenoids

Accessory pigments that absorb light in the blue-green range and protect against damage from excess light.

Ecosystem

A biological community of interacting organisms and their physical environment.

Food Chain

A linear network of organisms through which nutrients and energy pass as one organism eats another.

Photosynthesizers

Organisms that perform photosynthesis, such as plants, algae, and some bacteria.

Carbon Cycle

The series of processes through which carbon compounds are interconverted in the environment.

Biosphere

The global sum of all ecosystems, encompassing all living beings and their physical environment.

Photosynthetic Pigments

Molecules that absorb light energy for photosynthesis.

Chloroplast DNA

The genetic material found in chloroplasts, inherited maternally in many plants.

Glucose Utilization

The process by which glucose is used for energy, growth, and cellular processes in organisms.

Food Production

The process by which plants synthesize food through photosynthesis.

Oxygen Production

The release of oxygen gas as a byproduct of photosynthesis.

Bioenergetics

The study of the transformation and transfer of energy in living organisms.

Primary Producers

Organisms that produce their own food from sunlight or chemical energy, forming the base of the food chain.

Aerobic Respiration

A process where organisms use oxygen to convert organic molecules into energy.

Plant Growth

The process through which plants increase in size and develop over time.

Oxygen Consumption

The uptake of oxygen by organisms for the process of respiration.

Trophic Levels

The hierarchy of feeding relationships in an ecosystem.

Energy Flow

The transfer of energy from one organism to another within an ecosystem.

Dynamic Equilibrium

A state of balance in ecological systems, often involving competition and resource availability.

Glucose Storage

The process by which excess glucose is stored by plants, often as starch.

Photosynthetic Efficiency

The effectiveness of photosynthesis in converting sunlight into chemical energy.

Nitrogen Cycle

The series of processes by which nitrogen is converted to various chemical forms in the environment.

Phosphorus Cycle

The movement of phosphorus through the lithosphere, hydrosphere, and biosphere.

Sulfur Cycle

The cycle in which sulfur moves through the environment and is incorporated into biological molecules.

Metabolism

The set of life-sustaining chemical reactions in organisms.

Nutrient Uptake

The process by which plants absorb essential nutrients from the soil.

Carbon Dioxide Fixation

The initial step in the Calvin cycle where carbon dioxide is incorporated into an organic molecule.

Photosynthetic Rate

The rate at which photosynthesis occurs in plants, influenced by various environmental factors.

Energy Carriers Role

The function of molecules like ATP and NADPH in transferring energy within cells.

Photosynthesis Experiment

An experimental setup to measure the rate and efficiency of photosynthesis under varying conditions.

Biological Indicators

Organisms or processes that reflect the state of an ecosystem, used in studies of photosynthesis.

Ecological Interactions

The relationships between different organisms in an ecosystem, which can influence photosynthesis.

Biomass Production

The generation of organic material from living or recently living organisms, often measured in relation to photosynthesis.

Chemiosmosis in Mitochondria

The process similar to chemiosmosis in chloroplasts, occurring in mitochondria during cellular respiration.

Photosynthetic Variables

Factors that can influence the rate of photosynthesis, such as light intensity and CO₂ concentration.

Adaptive Strategies

Methods by which entities adjust to changing environments to enhance survival or efficiency.

Agricultural Practices

Techniques used in farming that impact the efficiency of photosynthesis and biomass production.

Sustainable Energy Practices

Methods of energy use that are sustainable and can be maintained without depleting resources.

Climate Influence

How changes in climate can affect photosynthesis and associated processes.

Seasonal Variability

Fluctuations in biological processes, such as photosynthesis, that occur due to seasonal changes.

Nutrient Cycling

The movement and exchange of organic and inorganic matter back into the production of living matter.

Sunlight Capture

The process by which plants absorb light energy necessary for photosynthesis.

Photosynthesis and Evolution

The role of photosynthesis in the evolution of life on Earth and its impact on global ecosystems.

Biological Efficiency

How effectively living organisms convert nutrients or energy from one form to another.