Taxus brevifolia- The Pacific Yew



The Pacific Yew is known as a photoautotroph. This means that it’s able to make its own food through a process called photosynthesis. In general, this is when the chloroplasts located inside the plant cells capture light from the sun and convert it into chemical energy that can be used by the plant. photosynthesis

When taking a closer look, we see that the first step in photosynthesis is the light reactions which are located in the leaves. During the light reactions, the chlorophyll pigments in the thylakoid membrane absorb and collect the light. The energy from the light is then bounced around in the membrane until it reachs the energy center. This energy is then used to make ATP and NADPH which are both forms of energy that can be used by the plant to make its food. The process of photosynthesis is dependent on water because water provides the electrons that keep the process going. This much-needed water is transported throughout the tree in the xylem.
leavesNow that we’ve made ATP and NADPH, we need to make the sugar.  This step occurs during the Calvin Cycle. Basically the Calvin Cycle involves three steps: fixation, reduction, and regeneration. All three of these steps occur in the stroma, or fluid, inside the chloroplasts of the cells. Through these three parts, a molecule called Ribulose biphosphate is converted into a sugar called Glyceraldehyde-3-phosphate with the help of the ATP and NADPH molecules created earlier in the light reactions. In order for one molecule of glucose (sugar) to be made, this cycle has to go through twice. Once the sugars are created, they get transported throughout the tree in the phloem .


Now that you've seen how the Pacific Yew is able to get energy to survive, take a look at the Reproduction page to see how it's able to reproduce and spread.