1. Pop Quiz scenario on feedback loops... BIOL 2010 Human Anatomy & Physiology I Refer to “Case Study” pg. 9. Discuss with a neighbor be ready to share with class…

2. How does chemistry relate to feedback loops and Human A&P? Before we answer that question, let’s explore what you already know (or don’t know) about chemistry! How did you do with Assg. 1?

3. Now let’s focus our attention on more chemistry... FOOD!!! Let’s look at a specific variable in our bodies: We will refer to this variable as we discuss both feedback loops and chemistry as they pertain to eating PRETZELS.

4. Do pretzels have mass or weight? Do pretzels have energy? If so, what type(s)? Are pretzels comprised of atoms, molecules or compounds? Let’s look at the periodic table What’s in a pretzel? Let’s list the ingredients…

5. Which of the ingredients we listed are “inorganic”? What would be classified as “organic”? Looking at our salt… Is it “held together” by covalent or ionic bonding? When we eat the pretzel and add water (from our saliva) what happens to the salt? Why?

6. 131 I and 127 I what is the difference? One is stable and one decays into a different element (half-life of 8 days).

7. How are these two types of chemical bonds different? = atoms gain or lose electrons & stay associated by different charges. = atoms share electrons and stay associated based on attraction of other’s e -

8. What inorganic compounds are important to the human body?

9. What is an acid? What is a base? Buffers?

10. Chemical reactions and energy… Synthesis vs decomposition Speed of reactions

11. 1) 2) 3) 4) 5) What are the main groups of organic compounds…?

12. 1) Comprised primarily of “Like dissolves Like” Different combinations: What are the main groups of organic compounds…?

13. 2) Also carbon & “hydrate” but … Consequently “Like dissolves Like” Different types: ~___% of fats in our bodies What are the main groups of organic compounds…? ?

14. 2) Looking at the different atoms combining to form the phospholipid, which region would you predict to be POLAR and which region NON-POLAR? ???? What are the main groups of organic compounds…?

15. 3) Also comprised of carbon & “hydrate”, but _________ also an important component Can have _________ and other elements Different levels: Refer to pg. 47 What are the main groups of organic compounds…?

16. What is an enzyme again? Cofactors or coenzymes? Examples…

17. 4) Comprised of carbon & “hydrate” but also ________________and _______________ Depending on sugar either… 5 nitrogen bases: What are the main groups of organic compounds…?

18. 5) Comprised of similar components as nucleic acids… What’s different? Important “currency” of ______ in the body Which has more potential/chemical energy... ATP ( adenosine tri phosphate ) or ADP ( adenosine di phosphate )? What are the main groups of organic compounds…?

19. When we “dump” excess sodium (Na + ) into the system how is homeostasis maintained??? What 3 components probably exist? 1) Receptor 2) Receiver (control center) 3) Effector

20. Is this a positive or negative feedback loop? + -

21. Is the sensation of thirst associated with a negative or a positive feedback mechanism? Why? Take 5! Discuss with your neighbor and predict an answer.