M5 Recap Blog Post at Sahm-I-Am
--Review how to balance equations with this video.
--Then play Balancing Act! Choose Beginner.
(6) p. 140-142a Photosynthesis
In photosynthesis, a plant takes (1) carbon dioxide, (2) water, and (3) the energy from sunlight and converts them into (A) a simple sugar called glucose which the plant needs for food, and into (B) oxygen which it does not need, but gives off for us to breathe.
(there is a fourth thing needed, mentioned below)
"Carbon dioxide and water interact to make glucose and oxygen."
Carbon dioxide + water → glucose + oxygen
--But it takes 6 molecules of carbon dioxide and 6 molecules of water to get 1 molecule of glucose for the plant, and 6 molecules of oxygen left over. The oxygen is sometimes called a by-product or waste product. It isn't waste to us, but it is to the plant.
6CO2 + 6H2O → C6H12O6 + 6O2Memorize this chemical equation. Know the elements in each molecule, and what molecule they combine to make. (For example, H2O is 2 atoms of hydrogen and 1 atom of oxygen. Together they make water)
►The molecules to the left of the arrow are called reactants. They react to make a product.
So the 6 molecules of carbon dioxide and 2 molecules of water are the reactants.
6CO2 + 6H2O → C6H12O6 + 6O2The molecules to the right of the arrow are called products.
So the 1 molecule of glucose and 6 molecules of oxygen are the products. They are produced as a result of the chemical reaction.
►►In order for photosynthesis to happen, more is needed than just carbon dioxide, water, and sunlight.
A fourth thing is needed called a catalyst, which speeds up a process. And in a plant that catalyst is usually chlorophyll. Chlorophyll, a green pigment, exists in a part of the leaf called chloroplasts. The job of chlorophyll is to speed up photosynthesis so plants will have enough glucose for food.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ (7) p. 142, Organic Chemistry ►An organic molecule is one that contains only carbon and any of the following: hydrogen, oxygen, nitrogen, sulfur, and/or phosphorous. If you memorized these last week, you will easily recognize these six elements. Look in your textbook on p. 142 for examples of organic molecules and some that are not, and why. Memorize these. ►Photosynthesis is an example of biosynthesis since photosynthesis takes smaller molecules (water and carbon dioxide) and makes a larger one (glucose).
6CO2 + 6H2O → C6H12O6 + 6O2~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ (8) p. 142-146 Carbohydrates ►Carbohydrates contain only carbon, hydrogen, and oxygen. You can see the 'carbo' in the name, for carbon. And hydrogen and oxygen make water, thus 'hydrate' in the word carbohydrate. You may know that carbohydrates give you energy, and you've learned that glucose is a simple sugar. Look at a molecule of glucose: C6H12O6 You can see there are 6 atoms of carbon, 12 of hydrogen, and 6 of oxygen. There are twice as many hydrogen atoms as there are oxygen. This is the same ratio as one molecule of water, H2O. ►When a molecule of glucose is drawn in structural formula, it shows which atoms are linked to which. When the atoms are linked in a straight line, we call it a chain structure. (on the left below) The chain structure of the glucose molecule below has a line of Carbon atoms, called a carbon chain. But many atoms have more than one structural formula. The most commonly accepted form of glucose is the ring structure. These diagrams are not drawn exactly like the ones in the textbook, but if you look closely and compare to those in your textbook, you can see these indeed do represent glucose. In the ring structure on the right below ↓, CH2OH consists of the same atoms as drawn in your textbook, and the same as the chain structure here on the left, where C links to 2 H's, and to OH. You will remember in your textbook, in the chain formation, one oxygen atom had 2 lines linking to a carbon atom. Here in the chain formation on the left, the solitary oxygen atom does have 2 links. If you look carefully and find that same oxygen atom in the ring formation on the right, you will again see the oxygen has 2 links linking to carbon. ETA: You will notice that the Oxygen is always connected to the Carbon. That is why in the chain structure here on this blog, HO is written instead of OH. The chain structure is vertical, so HO must be written this way so that the O is connected to the C. (I emailed Apologia; ha, I am not that smart!) I was also told whether it was written as OH or HO did not matter as long as the Oxygen was attached to the Carbon. This is not apparent in the figures in your textbook, as the picture is drawn horizontally, and the connecting line seems to attach to both the O and H, but here it is clear that the Carbon is attached directly to the Oxygen.
C6H12O6 + C6H12O6 → C12H22O11 + H2ORemember, sucrose is a disaccharide because it was formed from two monosaccharides in the process of dehydration. ►What two molecules combine in a dehydration reaction to make the disaccharide lactose? When several monosaccharides link together, it is called a polysaccharide. Polysaccharides aren't usually sweet. An example is starch, and is found in most plants. When a plant has extra monosaccharides, it will store them as polysaccharides by having many dehydration reactions that link the monosaccharides together. Kind of like when your Mom has a lot of a apples, she may dehydrate some to use in baking later, except in a dehydration reaction, not only do the monosaccharides lose water, they are actually combined into polysaccharides. If they are now polysaccharides because they have lost water, what will the plant do to turn them back into monosaccharides? The opposite of dehydration is hydration. The plant breaks down disaccharides or polysaccharides back into their monosaccharide components by adding water. This is called hydrolysis. (Think of the word hydrate.) When humans and animal have excess carbohydrates, their bodies make a starch called glycogen. So the reverse of the dehydration of fructose and glucose to form sucrose, would be hydrolysis of sucrose to make glucose and fructose. This chemical reaction is achieved by honeybees when they make honey. ►If you want, you can read more here about this and other processes we have studied. Also see "Respiration" which is mentioned in the next Module. See if you recognize the molecules. =) ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ (9) p. 146-147, Organic Acids and Bases Acids usually taste sour, while bases tend to taste bitter. Fruit juice contains acid, and many cleaning products contain bases.
|This molecule has an acid group, |
so this molecule is an organic acid.
- deoxyribose (a simple sugar that contains 5 carbons)
- a phosphate group (an arrangement of 3 things: phosphorous, hydrogen, and oxygen atoms - see the picture on the right of Figure 5.10 in your textbook)
- a nucleotide base