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The rise of an oxygen-rich atmosphere had profound impacts on life. Which of the following is a major benefit of an oxygen atmosphere for complex life forms?

Adenosine triphosphate (ATP) is the primary energy currency of the cell. Its structure consists of a nitrogenous base called adenine, a five-carbon sugar called ribose, and three phosphate groups. Based on these components, ATP is classified as which type of macromolecule?

A scientist is studying biochemical pathways in a bacterium, those that break down complex molecules to release energy, and those that use that energy to build new, complex molecules. What two major categories of metabolic processes are they studying?

The human stomach produces gastric acid with a pH between about 1.5 to 3.5. If an individual with a gastric acid pH of 2.0 drinks coffee with a pH of 5.0, how does the pH of each of these (the gastric acid and coffee) compare?

A yeast cell is performing aerobic respiration. What are the final waste products and main energy output of this process?

Consider what you have learned in Unit 2 of this class. Please pick a single topic, e.g., a single learning objective we have covered. This might be something you found especially interesting, something you initially struggled with but then learned well, something you are especially confident of and perhaps wished was covered more thoroughly on this test, or anything else you want from this content, except please do not pick one of the topics already discussed in the essay questions (i.e., do not re-discuss the essay questions you already answered). For this topic: Identify the topic Explain the topic and why it is important Write a single multiple choice question addressing this topic Your answer should be a paragraph of at least 4-5 sentences. Please do not just list out names of multiple topics, or just tell me that you found a topic to be really interesting. You may tell me you found this topic especially interesting, but you must demonstrate that you learned about and understand this topic by explaining it clearly. Note that there is not a single answer to this question, this is your chance to demonstrate good knowledge of any topic of your choosing from your work in this unit!

Lactase persistence, the ability to digest lactose into adulthood, is a trait prevalent in some human populations but not others. Which of the following best explains the evolutionary advantage that led to the spread of lactase persistence in certain populations?

The enzyme hexokinase catalyzes the first step of glycolysis by adding a phosphate group to glucose. If N-Acetyl-d-glucosamine (NAG) is introduced into the cell, it occupies the active site of hexokinase, thereby preventing glucose from binding, and thus stopping glycolysis. NAG is therefore an example of what?

Consider cellular respiration and photosynthesis in a plant. In cellular respiration, the source of electrons is ______, whereas in photosynthesis, the source of electrons is ______.

A plant leaf performs photosynthesis. Which of the following is the most accurate definition of this process?