Name: ________________________ Biology-Harlacher Chapter 9-Energy in a Cell Notes In this Chapter we will discuss two main concepts: __________________-when autotrophs/producers make sugar using sunlight. ___________________________-when any organism turns a sugar into energy ATP In our cells, we need energy in order to carry out vital cell processes (and live). Most of our energy is in the form of a molecule called Adenosine TriPhosphate (_______). ATP has a related molecule called Adenosine DiPhosphate (______). ADP can store energy by adding a phosphate group which makes ATP. When ATP loses a phosphate group, this __________________. It works like a battery that can be recharged. ATP is only used for ____________________________________, so only a small amount is found in cells. To store energy long term, cells use the basic sugar glucose (_________). The glucose can then be broken down as needed and used to _____________ ADP into ATP. Photosynthesis Photosynthesis is the process of changing __________________ into storable and __________________ for a cell. ATP is a good storage molecule for the day, but what about longer periods without light (like night)? Photosynthesis turns light energy into ___________, which can then be turned into _________ for longer-term energy storage. Photosynthesis uses carbon dioxide and water to turn light from the sun into glucose and oxygen gas. The formula for photosynthesis is: Pigments and Light How do plants do this? They use a ___________ called __________________ which exists in chloroplasts. Sunlight looks white to us, but is actually a _____ of all the different colors (visible and invisible to us). Plants gather the sun’s energy with light absorbing molecules called pigments (which are _____________). The three types of pigments in plants are _________________________________________ Chlorophylls are the major pigment in plants, but _________________________green well. What happens if a color of light is not absorbed? It is _____________. This is why most plants appear _________ to us. This is also why we see different colored leaves in the _________…the chlorophyll is no longer produced and we see the other pigments that still remain (for a time). There are two main types of Chlorophyll: __________________ __________________ When plants absorb light, much of the energy is transferred directly to _________, which allows photosynthesis to work. Inside a Chloroplast Chloroplasts, you should remember, only exist inside __________________ and the cells of other producers. Inside the chloroplast are sac-like membranes called __________________. They are arranged in stacks called _________. (Granum for one.) Proteins in the thylakoids arrange the pigments into clusters known as ________________. These are what collect light inside of a chloroplast. There are two parts to Photosynthesis: The ____________________________________ which take place within the thylakoids. The __________________ (or Dark Reactions or Light-Independent Reactions) which takes place in the stroma. The stroma is the space inside the chloroplast that is not taken up by thylakoids. Energy Transfer: When the electrons within chlorophyll are _________, they gain a lot of _________. Think of it as a hot charcoal briquette from a fire. If you wanted to move it, you wouldn’t pick it up with your hands, you would use a carrier. Cells treat them the same way. Cells use __________________ to transport them. The process is called electron transport (duh) and the carriers are known as ____________________________________. Some of the notable carriers: _______ holds two electrons and a Hydrogen ion (H+). This changes it into _______. _________ holds two electrons and an H+ ion. This changes into _________. _________ holds two electrons and two H+ ions. This changes into _________. These carriers can then be used to carry electrons throughout the cell to be used where needed. The Light-Dependent Reactions (or the Light Reactions) These reactions __________________. This is why plants need light. The light reactions produce oxygen gas and turn ADP and NADP+ into ATP and NADPH respectively. It happens in ___________________________: First, pigments in __________________ absorbs light. This excites the electrons and raises their energy levels. These electrons are then passed on to the electron transport chain. New electrons are gained from __________________. Enzymes inside of the thylakoid break each H2O into 2 electrons, 2 H+ ions, and 1 oxygen atom. The two electrons replace the electrons lost by chlorophyll to the electron transport chain. Oxygen is __________________ and released into the air. This is the source of almost all of our oxygen on earth. The _________ hydrogen ions from water are released within the thylakoid. Second, the excited electrons move through the electron transport chain to _______________ Energy from the electrons is used to transport H+ ions from the _________ to inside the _________________. Third, pigments in Photosystem I use energy from light to ___________________________. NADP+ picks them and H+ up and becomes NADPH. Fourth, as electrons are ________ from chlorophyll to NADP+ more H+ ions are pumped across the thylakoid membrane. The inside of the thylakoid fills up with __________________H+ ions. This makes the outside membrane negatively charged. The difference between the inside and outside in charge provides the energy to make _________. Fifth (and last), H+ ions can’t just cross the membrane. However, they can pass through a protein called ATP synthase which is a __________________. As the H+ ions pass through ATP synthase the protein is turned like a ______________ and it binds ADP and a phosphate group together to make ATP. This means that the light reactions produce H+ ions and ATP. But what do we do with all this _________ and _________? The Dark Reactions The __________________ are more commonly called the __________________. They occur in the _________ of the chloroplast. ATP and NADPH can hold energy, but are ___________________________ to hold onto that energy for more than a __________________. During the Calvin Cycle, plants (and other producers) use the ATP and NADPH to build highenergy compounds that can stored for a long time. It does this with __________________ _________ such as glucose. It happens in 4 parts: First, ____ carbon molecules enter the cycle from the atmosphere (courtesy of ______). These each combine with a 5-carbon molecule called RuBP (six total). The result is 12 molecules of ___________________________. Second, our twelve 3-carbon molecules are converted into higher energy forms. This energy comes from _______ and _________ made in the light reactions. This leaves us with _________ and _________ to return to the thylakoids and be used again. The end product is called _________. Third, two of the twelve 3-carbon molecules are removed from the cycle. The cell uses these to make sugars, lipids, amino acids, and other compounds that are needed for _____________________________________________. Fourth, the remaining ten 3-carbon molecules are ___________________________ into six 5carbon molecules (_________). They _________ the cycle again. The Calvin Cycle needs __________________ of CO2 to produce one glucose (_________). The plant then uses glucose to make _________ (storage), _____________ (structure), and just to break down for energy in cellular respiration. When other organisms eat plants, they get the energy from these __________________. Rates of Photosynthesis Amount of _________ available. _______________ (the essential enzymes must be between 0°C and 35°C (32-95 degrees F). The intensity of _________. Because of this different producers are adapted to different conditions! Think of a cactus, vs. an oak tree vs. a pine tree.