Biology, Chap. # 7 Photosynthesis: Using light to make food
Order by
32 terms
Terms | Definitions |
|---|---|
 Photosynthesis | Transform light energy to chemical engergy stored in the bonds of sugar they make from carbon dioxide and water |
| Autotrophs | Organisms that make their own food and thus sustain themselves without consuming organic molecules derived from any other organisms |
| Producers | Make the food for the organisms in the biosphere |
| Photoautotrophs | Organisms that produce organic molecules from inorganic molecules using the energy of light |
| Chlorophyll | A light-absorbing pigment in the chloroplasts that plays a central role in the chloroplasts |
| Mesophyll | The green tissue in the interior of the leaf |
| Stomata | Tiny pores where carbon enters and oxygen exits |
| Stroma | A thick fluid that is enclosed by the two membranes of the chloroplast |
| Thylakoids | Interconnected membranous sacs suspended in the stroma |
| Grana | Stacks of thylakoids |
| Light reactions | Absorb solar energy and convert it to chemical energy stored in ATP and NADPH |
| Calvin cycle | Consists of Carbon fixation, reduction, release of G3P, and regeneration of RuBP. Using carbon from CO2, electrons from NADPH, and energy from ATP, the cycle constructs G#P, which is used to build glucose and other organic molecules |
| Wavelength | The distance between the crest of two adjacent waves |
| Photon | A fixed quantity of light energy |
| Photosystem | Consists of a number of light-harvesting complexes surrounding a reaction center complex |
| Reaction center complex | Contains a pair of chlorophyll a molecules and a molecule called the primary electron acceptor, which is capable of accepting electrons and becoming reduced |
| Carbon fixation | Rubisco combines CO2 with a five-carbon sugar called ribulose bisphosphate (RuBP). The unstable product splits into two molecules of the three-carbon organic acid, 3-phosphoglyceric acid (3-PGA). For three CO3 entering, six 3-PGA result |
| Reduction | Two chemical reactions consume energy from six molecules of ATP and oxidize six molecules of NADPH. Six molecules of 3-PGA are reduced, producing six molecules of G3P |
| Release of one molecule of G3P | One molecule of G3P you see leaving the cycle is the net product of photosynthesis. A plant cell uses G3P to make glucose and other organic compounds |
| Regeneration of RuBP | A series of chemical reactions uses energy from ATP to rearrage the atoms in the five G3P molecules (15 carbons total), forming three RuBP molecules (15 carbons). These can start another turn of the cycle |
| 1st step of the Calvin cycle | Carbon fixation |
| 2nd step of the Calvin cycle | Reducation |
| 3rd step of the Calvin cycle | Release of one molecule of G3P |
| 4th step of the Calvin cycle | Regeneration of RuBP |
| Inputs of the light reactions | Energy from light, water, ADP + P, NADP+ |
| Outputs of the light reactions | oxygen, ATP, NADPH |
| Inputs of the Calvin cycle | CO2 |
| Outputs of the Calvin cycle | Sugar, NADP+, ADP + P |
| C3 plants | First organic compound produced is the three-carbon compound 3-PGA.Common and widely distributed; they include soy beans, oats, wheat and rice. |
| C4 plants | Alternate modes of carbon fixation have evolved that save water without shutting down photosynthesis. Preced the Calvin cycle by first fixing CO2 into a four-carbon compound. Keeps its stromata mostly closed |
| CAM plants | These species are adapted to very dry climates. Pineapples, Cacti and succulent plants |
| Photorespiration | A metabolic pathway that consumes oxygen, releases carbon dioxide, generates no ATP |
First Time Here?
Welcome to Quizlet, a fun, free place to study. Try these flashcards, find others to study, or make your own.