2/2/15 CONCEPTS OF BIOLOGY REVIEW QUESTION 2/2/15 (Q2)

Transcription

1 2/2/15 BIOSC 10 ANNOUNCEMENTS 2/2 Today: Review chapter 1 Review Q (2 points) Lecture- chapter 2 Wed 2/4: Quiz (10 points, chapters 1-2) Lecture- chapter 3 What are the 8 properties of life? What are the levels of organization of living things? What is the naming system used for genus and species? What are the three domains of life? What topics cannot be addressed by the scientific method? What are inductive and deductive reasoning? Vocabulary not in your text: Independent variable(s)- set by researcher Dependent variable(s)- measured Standardized variables- equal in all groups Can a hypothesis be proven true using the scientific method? Control treatment(s)- independent variable removed or set at a standard level (ex: room temp REVIEW QUESTION 2/2/15 (Q2) The smallest unit of biological structure that meets the functional requirements of living is the: a. Tissue b. Organelle c. Cell d. Atom CONCEPTS OF BIOLOGY Chapter 2 CHEMISTRY OF LIFE 1

2 Life is made up of Matter FIGURE 2.1 What is the charge of a neutron? Electron? Proton? Foods such as bread, fruit, and cheese are rich sources of biological macromolecules. (credit: modification of work by Bengt Nyman) What about their mass? FIGURE 2.2 Atoms are made up of protons and neutrons located within the nucleus, and electrons surrounding the nucleus. What are isotopes? FIGURE 2.3 (typical hydrogen atom) Arranged in columns and rows based on the characteristics of the elements, the periodic table provides key information about the elements and how they might interact with each other to form molecules. Most periodic tables provide a key or legend to the information they contain. Image from Wikimedia What are radioisotopes? Would a long or short half-life be useful for archaeologists? For medical doctors or nuclear med techs? FIGURE 2.4 Image: quizlet.com The age of remains that contain carbon and are less than about 50,000 years old, such as this pygmy mammoth, can be determined using carbon dating. (credit: Bill Faulkner/ NPS) 2

3 FIGURE 2.5 Because of vacancies in the outermost shells, we see formation of chemical bonds FIGURE 2.6 An atom is at its most stable when all of the electron positions in the outermost shell are filled What is an ion? FIGURE 2.7 The water molecule (left) depicts a polar bond with a slightly positive charge on the hydrogen atoms and a slightly negative charge on the oxygen. Examples of nonpolar bonds include methane (middle) and oxygen (right). 2.2: PROPERTIES OF WATER FIGURE 2.8 WATER IS POLAR Hydrogen bonds form between slightly positive (δ+) and slightly negative (δ ) charges of polar covalent molecules, such as water. What are van der Waals interactions? WATER STABILIZES TEMPERATURE As this macroscopic image of oil and water show, oil is a nonpolar compound and, hence, will not dissolve in water. Oil and water do not mix. (credit: Gautam Dogra) Is oil hydrophilic or hydrophobic? WATER IS AN EXCELLENT SOLVENT FIGURE 2.9 FIGURE 2.10 (a) The lattice structure of ice makes it less dense than the freely flowing molecules of liquid water. Ice s lower density enables it to (b) float on water. (credit a: modification of work by Jane Whitney; credit b: modification of work by Carlos Ponte) What happens when the temperature of water increases? When table salt (NaCl) is mixed in water, spheres of hydration form around the ions. 3

4 2/2/15 WATER IS COHESIVE BUFFERS, PH, ACIDS, AND BASES The ph scale measures the amount of hydrogen ions (H + ) in a substance. (credit: modification of work by Edward Stevens) FIGURE 2.11 Is high ph more acidic or more basic? While acids provide H +, what do bases provide? The weight of a needle on top of water pulls the surface tension downward; at the same time, the surface tension of the water is pulling it up, suspending the needle on the surface of the water and keeping it from sinking. Notice the indentation in the water around the needle. (credit: Cory Zanker) What is an example of adhesion? FIGURE 2.12 What ph do our body cells maintain? What do buffers do? 2.3: BIOLOGICAL MOLECULES CARBOHYDRATES (CHO) FIGURE 2.13 FIGURE 2.15 Carbon can form four covalent bonds to create an organic molecule. The simplest carbon molecule is methane (CH 4 ), depicted here. What are the four major classes of biological macromolecules? Glucose, galactose, and fructose are isomeric monosaccharides, meaning that they have the same chemical formula but slightly different structures. What is a disaccharide? POLYSACCHARIDES LIPIDS FIGURE 2.16 Although their structures and functions differ, all polysaccharide carbohydrates are made up of monosaccharides and have the chemical formula (CH 2 O)n. FIGURE 2.17 Hydrophobic lipids in the fur of aquatic mammals, such as this river otter, protect them from the elements. (credit: Ken Bosma) What are some polysaccharides used for energy storage in organisms? Are lipids polar or nonpolar? 4

5 PROTEINS LIPIDS Amino acids such as alanine, valine, lysine, and aspartic acid, are the building blocks of proteins. FIGURE 2.20 What are some functions of proteins? FIGURE 2.18 Lipids include fats, such as triglycerides, which are made up of fatty acids and glycerol, phospholipids, and steroids. Phospholipids are the major constituent of cell plasma membrane The four levels of protein structure play an important role in function NUCLEIC ACIDS FIGURE 2.22 A nucleotide is made up of three components: a nitrogenous base, a pentose sugar, and a phosphate group. Nucleic acids carry the genetic blueprint and instructions of a cell FIGURE 2.21 DNA AND RNA ARE THE TWO MAIN TYPES OF NUCLEIC ACIDS HOMEWORK FOR WEDNESDAY 2/4 Study chapters 1 and 2 for Wednesday s quiz Read chapter 3 FIGURE 2.23 The double-helix model shows DNA as two parallel strands of intertwining molecules. (credit: Jerome Walker, Dennis Myts) 5