UNIT 2: The Chemistry of Life Daysheet 25: Unit 1 Assessment & Introduction to Water Name: Biology I Date: Bellringer: Directions: 1. Go to www.biomonsters.com 2. Click on the Courses link. 3. Click on the Unit Nerd Words & E Flashcards link 4. Pick any Study Stack pile to review vocabulary for the assessment. Objective: I can demonstrate my understanding of biology content by mastering my Unit 1 Assessment. I can analyze the relationship between water s structure and its function in living systems. Homework: Complete HW#25. Activity 1: Unit 1 Assessment 1. Go to www.biomonsters.com 2. Click on the Courses link. 3. Click on the CHS Academic Biology link. 4. Click on the QuizStar link. 5. Log into your QuizStar account. 6. Begin the Unit 1 Assessment
Activity 1: Cornell Notes Biology Objective: Label the parts of the atom below: STOP-AND JOT: What is the charge on a proton? What is the charge on a neutron? What is the charge on an electron? The glue that holds atoms together is There are two types of chemical bonds: o bonds = chemical bonds formed by sharing electrons o bonds = force of attraction between oppositely charged ions Label the pictures below as covalent or ionic:
Essential Questions Notes: How do atoms form bonds? Draw a picture of a water molecule in the space below: Water has = the electrons are not shared equally between the oxygen and the hydrogens! Oxygen hogs the electrons! Go back to the picture of the water molecule above. Label the charges on the picture of your water molecule above. = water molecules stick to each other = water molecules stick to other substances = water is really good at dissolving stuff! Water is dense as a solid than liquid = ice floats on water! Pick a property of water from the list above. Why is this property important to living things?
Label the ph scale below with the following words: acidic, basic, neutral Give an example of an acid: Give an example of a base: Give an example of a neutral substance: What is the only substance with a neutral ph? Summary: Match the properties of water on the LEFT with an example on the RIGHT Water molecules stick to each other on the surface of a pond, making a surface that bugs can walk on Water in our blood can dissolve and carry nutrients throughout our body Icebergs floating in the Arctic Ocean provide a habitat for polar bears Water sticks to plant stems, helping water move up a plant A. Universal Solvent B. Adhesion C. Less dense as a solid than a liquid D. Cohesion
Activity 3: Introduction to Biochemistry and Water Purpose: To understand the structure of a water molecule Task: As you read the paragraphs below, highlight information that relates to the question on the left Outcome: Answer the questions and create your own water molecule model! 1. How do atoms bond together to form molecules? A molecule is made when different atoms create chemical bonds. The way atoms create these bonds is by sharing their electrons. In a water molecule, one oxygen and two hydrogen bond together by sharing their electrons. However, they do not share the electrons equally. Oxygen hogs the electrons! 3. What do we mean when we say water is polar? Remember, electrons have a negative charge. So when oxygen hogs the electrons it gets a slight negative charge. And when the hydrogen loses some of its electrons, it gets a slight positive charge. Because water has slight positive and negative charges we say that it is polar. Hydrogen Stop hogging all the electrons! Electrons - - I do what I want! Oxygen 3. Why are water molecules sticky? Because water molecules are polar (they have slight positive and negative charges), water molecules are "sticky." When you put two water molecules together, the negative oxygen and positive hydrogen are attracted to each other and stick together. Water's "stickiness" makes it able to do lots of cool things in nature that are really important to living things! For example, water molecules on the surface on ponds stick together so well, some insects can walk on them!
HW25: Properties of Water Biology I Name: Date: Directions: Match the following properties of water with their correct definition POLARITY COHESION SURFACE TENSION CAPILLARY ACTION UNIVERSAL SOLVENT ADHESION A. Because water molecules stick together, they form a thin film on the surface of pools of water, on which some organisms can walk B. Water molecules are able to move against the force of gravity up plant stems C. Because of its polarity, water molecules are attracted and stick to other molecules, making water really good at dissolving a wide variety of substances D. Because of its polarity, water molecules are attracted and stick to one another E. A water molecule has slight positive and negative charges. This makes the molecule sticky F. Because of its polarity, water is attracted to and sticks to other substances CONTINUED ON BACK!!!!!
Directions: Describe in 1 2 sentences why each of the following unique properties of water is important to living things Water is the universal solvent: Water is less dense as a solid than as a liquid Water molecules are attracted to one another (cohesion) Water molecules are attracted to other substances (adhesion)