Please use accurate information from the book only.

BIOL2020 Lecture Exam 3

• (30 points) Using the diagram provided below, explain how the kidneys are able to filter our blood in such a way that only what is not needed will be excreted, while important things such as water are retained. Be sure to include/address the following:

1. Label the diagram below with names of nephron regions, names of kidney regions, and what the nephron membrane is permeable to at each region.
2. DescribeNET Glomerular filtration pressure.What pressures create this pressure?
3. Describe in detail what happens to the filtrate (what is filtrate anyway?) as it courses through this structure.
4. How do the vasa recta and medullary osmotic gradient contribute to the ‘end product’?

• (30 points) How can one gain the nutrients from a meal of a turkey sandwich and potato chips (or veggie sandwich, for vegetarians) to sustain the body’s energy demands? (Assume this meal contains ingredients for all 3 of the macromolecules we’ve been discussing.)

1. Walk through the process of digestion from the mouth to the end of the small intestine (beginning of large intestine) for the three main macromolecules that we absorb from this meal. Include a description of how the food is digested; what enzymes are required and in which regions of the digestive tract? Are there any accessory organs are involved? How is this food absorbed into the body? Be specific for each macromolecule.
2. b) Once you have walked through the digestion and absorption of this meal’s components, where do they go in the body?

• (20 points) In regards to the meal described in question #2, how can cells of your tissues/organs use these absorbed macromolecules to form energy? Be sure to list/describe all of the ways energy can be formed, and which macromolecule(s)will undergo substrate phosphorylation and which one(s)can be used most readily from food foroxidative phosphorylation.

• (20 points) A common theme throughout this course is how our bodies are able to maintain homeostasis. The kidneys play a critical role in helping maintain one’s homeostasis.

1. List two ways in which the kidneyswork to maintain the body’s homeostasis.
2. Describe each of these ways in detail. Be sure to include the following: (this list is not inclusive!! If there’s more to say, say it.)What pathways, or steps are involved? Are therereceptors that detect changes? What are the kidneys’ response? Are there any hormones involved?