NOTE: The provided figures may be useful and beneficial. Use them at your discretion, remember your book has a lot of great diagrams don’t skip the ones I didn’t pick! Keep up the good work & be an Intentional Learner.

Learning Log Chapter 7

  1. Why are membranes considered selectively permeable? In your answer, please include the items that are selected for, selected against & state why.
  2. The most accepted model of membrane structure as of this time is the fluid mosaic model. Explain the meaning behind the terms “fluid” and “mosaic”.
  3. The soil immediately surrounding around hot springs is much warmer than that of neighboring regions. Two closely related species of native grasses are found, one in the warmer region and one in the cooler region. If you analyzed their membrane lipid compositions, what would you expect to find? Explain!!
  4. Use Figure 7.5 to describe the fluidity of a membrane. How does cholesterol affect membrane fluidity? How does temperature affect membrane fluidity?
  5. Do Membrane proteins move? If so explain how… can you explain why?
  6. Why do integral proteins stay in place in the phospholipid bilayer?
  7. What are aquaporin’s and why are they important?
  8. Use Figure 7.10 to describe the “2 faces” of a membrane.
  9. Contrast and compare passive and active transport. How are they different? What kind of

molecules are moved by each? Which direction do the materials move?

  1. Use Figure 7.13 to describe the flow of water in hypertonic, hypotonic & isotonic solutions. How is this different in an animal & plant cell? Really think about this!
  2. Use Figure 7.17 to describe the movement of molecules in active & passive transport across a selectively permeable membrane.
  3. The Na+ - K+ pump, the major electrogenic pump in animal cells, exchanges sodium ions for potassium ions, both of which are cations. How does this exchange generate a membrane potential or difference in electrical charge since both ions have the same charge? (what is an electrogenic pump anyway?  ).
  4. In Concept 6.7, you learned that animal cells make an extracellular matrix (ECM). Describe the cellular pathway of synthesis and deposition of an ECM glycoprotein.

Learning Log Chapter 8

  1. Discuss the forms of energy found in an apple as it grows on a tree, then falls, then is digested by someone who eats it. How does ATP usually transfer energy from exergonic to endergonic reactions?
  2. In thermodynamics, what is the difference between an “open” system versus a “closed”

system? Which one best reflects living things?

  1. Compare and contrast a system with high free energy versus a system with low free

energy for the following: work capacity, equilibrium, spontaneous, stability.

Work / Direction of Equilibrium / Spontaneous or not / Stable or not
High free energy
Low free energy
  1. Contrast and compare exergonic reactions versus endergonic reactions. Which reaction type matches with catabolic reactions? Which matches with anabolic reactions?
  2. When a cell becomes more ordered, one of the characteristics of life, what must happen in the rest of the universe? Which Law of Thermodynamics does this reflect?
  3. What is free energy? **** Read section 8.2 very carefully it isn’t as hard as it seems! 
  4. Explain why ATP can store so much energy.How is ATP similar to the monomers that make up the nucleic acid RNA? Explain
  5. The hydrolysis of ATP uses what and yields what? (hint define hydrolysis)
  6. What is the opposite of the hydrolysis in question 7?
  7. Look at figure 8.14 pg. 152. Draw the progress of an endergonic reaction in which EF and GH form products EG and FH, assuming that the reactants must pass through a transition state.
  8. Use Figure 8.15 to explain the function of enzymes.
  9. Use Figure 8.17 to illustrate why enzymes are substrate-specific & how an enzyme’s microenvironment in its active site plays an active role in the enzyme’s function.
  10. Use Figure 8.19 & 8.20 to explain how the following factors influence enzyme activity. Please consider both an increase & decrease in activity with your discussion as well as a discussion about normal activity.
  11. Temperature
  12. pH
  13. salinity
  14. co-factors
  15. competitive inhibitors
  16. allosteric inhibitors
  17. allosteric activators
  1. Imagine you are a pharmacological researcher who wants to design a drug that inhibits a particular enzyme. Upon reading the scientific literature, you find that the enzyme’s active site is similar to that of several other enzymes whose activity must remain unchanged. What might be a good approach to developing your inhibitor drug so that it only inhibits the specific enzyme of interest?
  2. Look at fig. 8.21 and read pg. 158.