Biology-Energetics Vocab

Energy

Energy

Ability to perform work

Autotrophs

Use energy from sunlight, Carbon Dioxide, and water to make food

Heterotrophs

Organisms that cannot make their own food

ATP

Energy storage molecule used by most organisms (adenosine triphosphate)

Reduction

Addition of electrons to an atom or ion

Oxidation

Loss of an electron to an atom or ion

Photosynthesis

autotrophs convert sunlight into usable energy

Pigment

molecule that absorbs certain wavelengths or light and reflects/transmits others

Chlorophylls

most common and important photosynthetic pigments in plants and algae

Chloroplasts

organelles that contain pigments and chlorophyll in which photosynthesis occurs

Thylakoids

disk-shaped structures that contain photosynthetic pigments

Stroma

gel-like matrix that surrounds thylakoids

Grana

neatly folded thylakoids that resemble stacks of pancakes

Photosystems

light collecting units of chloroplasts

ATP Synthase

H+ ions released by photosystem II accumulate in the Thylakoid space. In a process called chemiosmosis, the ions cross the membrane through an ATP synthase channel. The energy released by the flow of H+ converts ADP to ATP

Photosystem II

light absorbed by photosystem II is used to split water, releasing O2, H+, and energized electrons

Photosystem I

electrons released by photosystem II are energized again in photosystem I. Enzymes in the membrane use the electrons to form high energy NADPH. NADPH is used to make sugar in the Calvin Cycle

Electron Carriers

molecules transfer electrons to Photosystem I

Calvin Cycle

the carbon fixing reactors that use the products of light to convert carbon dioxide and water to sugars

Cellular Respiration

food molecules are broken down to release energy for work

Glycolysis

glucose is converted to pyruvate, and energy is released

Aerobic Respiration

breakdown of pyruvate in the presence of oxygen

Krebs Cycles

series of oxidation reactions that make up the second phase of aerobic respiration

Anaerobic respiration

chemical reactions that release energy from food molecules in the absence of oxygen

Alcoholic Fermentation

anaerobic respiration that converts pyruvate to CO2 and ethanol

Lactic Acid Fermentation

anaerobic respiration in which pyruvate is converted to lactic acid