AP Biology - Topic 1.2: Elements of Life PDF

AP BIOLOGY UNIT 1: Chemistry of Life Topic 1.2: Elements of Life © Getting Down with Science - All students will be able to list the elements found in macromolecules. DOK 1 - Almost all students will be able to describe the properties of elements that are essential for life. DOK 2 - Most of the st...

AP BIOLOGY UNIT 1: Chemistry of Life Topic 1.2: Elements of Life © Getting Down with Science - All students will be able to list the elements found in macromolecules. DOK 1 - Almost all students will be able to describe the properties of elements that are essential for life. DOK 2 - Most of the students will be able to explain the role of elements in the formation of macromolecules. DOK 3 Success Criteria: - I can identify the important elements by exploring the given macromolecules. - I can justify the importance of elements in forming the macromolecules by research. ENGAGE 5 Min Key terms: Biological macromolecules, carbohydrates, proteins, lipids, nucleic acids, hydrocarbon, isotopes, functional groups, Watch the Edpuzzle video based on Elements of Life- College Board Resource VIDEO Useful Links For Topic 1.2 EXPLORE: 10 Min https://openstax.org/books/biology-ap-courses/pages/2-3-carbon https://www.khanacademy.org/science/ap-biology/chemistry-of-life/elements-of-life/ a/matter-elements-atoms-article 2 https://library.fiveable.me/ap-bio/unit-1/elements-life/study-guide/kLZ8GN081XmA mZpivYFN https://prezi.com/4hefv2hk2bhq/ap-bio-matter-1-atoms-water-carbon/ VIDEO TASK: https://www.youtube.com/watch?v=QWf2jcznLsY  Carbon Organic chemistry: the study of compounds with covalently bonded carbon Organic compounds: compounds that contain carbon and hydrogen Carbon has 4 valence electrons  Carbon Carbon can form single, double, or triple covalent bonds A single carbon can form up to four covalent bonds! ○ Can form LONG chains Most commonly formed with hydrogen, oxygen, and The type and number of nitrogen covalent bonds carbon forms with other atoms affects the length of the carbon chain and shape of the molecule © Getting Down with Science  Carbon Chains Carbon can use its valence electrons to form covalent bonds to other carbons This links the carbons into a chain Hydrocarbons- organic molecules consisting only of carbon and hydrogen (think: simple framework for more complex organic © Getting Down with Science  Carbon Chains Carbon chains form the skeletons of most organic molecules Skeletons can vary in: ○ Length ○ Branching ○ Double bond position ○ Presence of rings Many regions of a © Getting Down with Science  HYDROCARBONS Hydrocarbons are organic molecules consisting entirely of carbon and hydrogen, such as methane (CH4) The many covalent bonds between the atoms in hydrocarbons store a great amount of energy, which is released when these molecules are burned (oxidized). The carbons and the four hydrogen atoms form a shape known as a tetrahedron, with four triangular faces; for this reason, methane is described as having tetrahedral geometry. HYDROCARBON CHAINS Hydrocarbon chains are formed by successive bonds between carbon atoms and may be branched or unbranched. Furthermore, the overall geometry of the molecule is altered by the different geometries of single, double, and triple covalent bonds, illustrated in Figure 2.24.  HYDROCARBON RINGS So far, the hydrocarbons we have discussed have been aliphatic hydrocarbons, which consist of linear chains of carbon atoms, and sometimes they can form rings with all single bonds, as shown in Figure 2.25 in the examples of cyclopentane and cyclohexane. Another type of hydrocarbon, aromatic hydrocarbons, consists of closed rings of carbon atoms with alternating single and double bonds. We find ring structures in aliphatic hydrocarbons, sometimes with the presence of double bonds, which we can see by comparing cyclohexane's structure (aliphatic) to benzene (aromatic) in Figure 2.25. ISOMERS: Molecules that share the same chemical formula but differ in the placement (structure) of their atoms and/or chemical bonds are known as isomers. (a) Structural isomers have a different covalent arrangement of atoms. (b) Geometric isomers have a different arrangement of atoms around a double bond. Reading Lin k (c) Enantiomers are mirror images of each other.  READING RESOURCE LINK Functional groups: chemical groups attached to the carbon skeleton that participate in chemical reactions https://courses.lumenlearning.com/wm-biology1/chapter/fun ctional-groups-2/ © Getting Down with Science  Water Free Response bb A farmer hears a news report regarding a frost advisory for his region. To protect his strawberry plants, he decides to spray water on the crops prior to the frost that evening and early morning. Using your knowledge of the structure of water and its properties, justify the farmer’s reaction to the frost advisory by explaining how two of the four emergent properties of water fit this example. © Getting Down with Science The four emergent properties of water are: Cohesion: Water molecules are attracted to each other, which helps them to stick together. This is why water forms droplets. Adhesion: Water molecules are also attracted to other surfaces, such as the leaves of a strawberry plant. This is why water can "climb" up a straw. High specific heat capacity: Water has a high specific heat capacity, which means it takes a lot of energy to heat it up or cool it down. This is why water can help to moderate the temperature of a plant, preventing it from getting too cold or too hot. High latent heat of vaporization: Water has a high latent heat of vaporization, which means it takes a lot of energy to turn water into steam. This is why sweating helps to cool us down, as the water evaporating from our skin takes heat away with it. © Getting Down with Science The farmer's reaction to the frost advisory is justified by two of these emergent properties of water: cohesion and high specific heat capacity. Cohesion: When the farmer sprays water on his strawberry plants, the water molecules will stick together and form a thin layer of ice on the leaves and stems of the plants. This layer of ice will act as an insulator, preventing the heat from escaping from the plants and keeping them from freezing. High specific heat capacity: The water in the ice will also absorb a lot of heat from the air, which will help to keep the temperature of the plants from dropping too low. © Getting Down with Science By spraying his strawberry plants with water, the farmer is taking advantage of the unique properties of water to protect them from frost damage. In addition to the two emergent properties I mentioned, the farmer's actions may also be helped by the fact that water has a high surface tension. This means that the water molecules will tend to form a tight film on the surface of the plants, which will help to prevent the heat from escaping. © Getting Down with Science ELABORATE: Create a sketch note or concept map as per your choice about the elements of life. OR use the Quizziz link to recap chemistry for Biology. https://quizizz.com/join?gc=71172526 EVALUATE: 5 Minutes Solve the assigned Topic 1. 2 Quiz - College Board