Bio 118 Test #1 notes

Bio 118 Test #1 notes - Homeostasis: What is homeostasis?...

Info iconThis preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
Homeostasis: What is homeostasis? What does it accomplish and how does it work? Homeostasis is the tendency for physiological systems to stabilize internal conditions; through homeostatic regulation these systems adjust to preserve homeostasis What is a negative feedback loop? Give an example. A variation outside normal limits triggers an automatic response that corrects the situation. Body temperature can differ, when it is too high, your sweat glands will secrete sweat in order to cool down the body. What is a positive feedback loop? Give an example. In the body, positive feedback loops are involved in the regulation of a potentially dangerous or stressful process that must be completed quickly. Blood clotting, blood flow continues quickly so it will clot. What are the levels of biological organization? Chemical (or molecular) level, Cellular level, Tissue level, Organ level, Organ System level, Organism level Atoms and inorganic chemistry: What are the four most abundant elements in the human body, and why are they the most abundant? Oxygen, Carbon, Hydrogen, Nitrogen (they make up carbohydrates and proteins) Name the particles that make up an atom. Proton, Neutron, Electron What is an electron shell, and how does this contribute an atom’s reactivity? (i.e., why is carbon reactive, while neon is inert?) The orbit of electrons; the electron in the outermost shell tells us the chemical properties What is covalent bonding? Name two molecules that are held together by covalent bonding. A bond made by sharing electron shelling; hydrogen molecule, oxygen molecule, CO2 What is an ion? Atoms or molecules with an electric charge
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
What is ionic bonding? Name a molecule that is held together by ionic bonding. Chemical bonds created by the electrical attraction between anions and cations (NaCl: Sodium Chloride) What are hydrogen bonds? The attraction between a slight positive charge on the hydrogen atom of one polar covalent bond and a weak negative charge on an oxygen or nitrogen atom of another polar covalent bond. Why is water a polar molecule? How does this polarity contribute to water’s surface tension, and its ability to dissolve substances like salt and sugar? Why can’t water dissolve lipids or oils? The shape of a water molecule makes it polar. What is an electrolyte? Name an example. Inorganic compounds whose ions can conduct an electrical current in solution; salt, Na + , K + , Ca 2+ , Cl - What is an amphipathic molecule? What makes it amphipathic? Name an example. A molecule that contains both polar and nonpolar regions What is an acid? What is a base? Name examples of both. Acid: any substance that breaks apart in solution to release hydrogen ions. (Vinegar) Base: a substance that removes hydrogen ions from a solution (baking soda) Understand the pH scale. 7: neutral
Background image of page 2
Image of page 3
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 02/24/2011 for the course BIO 118 taught by Professor Bilgen during the Spring '08 term at University of Washington.

Page1 / 9

Bio 118 Test #1 notes - Homeostasis: What is homeostasis?...

This preview shows document pages 1 - 3. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online