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Monthly Archives: October 2014

What’s important about… ATP?

Every Intro Bio student can cite ATP as ‘the energy currency of the cell’… but what do we mean by that? And why does it play that role? These are important questions, and they deserve answers. And real ones, not invocation of the mystical ‘high energy bonds’.

Perusing Wiki for an image to link for ATP, I’m surprised to find how many directly imply that the ‘value’ is in the bond between two phosphates. I think suggesting that this is the case does a disservice to students’ ability to analyze and understand. We’ve taught them by now that bonds are simply shared pairs of electrons. Blaming the bond for the potential energy inevitably raises the question “Is it the electrons that are special? If not, what is it about the bond?”. No and nothing.

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Energetics What's important about... | Bruce | | 2 Comments

What’s important about… biology’s Central Dogma?

‘What to teach’ in Introductory Biology presents a whole host of conundrums. Is our role to cover the breadth of all of biology (or all of the biology student will hear again in upper divisions) at breakneck pace and without depth? A whirlwind tour of vocabulary to commit to memory with vague understanding for some later date? I will argue periodically that we should pick a limited, integrated fraction of possible content and teach it in a way that allows students to see and grasp underlying concepts and universal themes, thereby enabling them to figure out what comes later, and to embark on their own to investigate whatever catches their fancy.Ribosomes translating mRNA

The key ideas of biology’s Central Dogma–or better put, the flow of information— are a critical case in point. We all agree that ‘something’ about DNA, RNA and protein is among our core duties. But what? My view is that identifying the roles of each of these players, how their structures fit them to play those roles, how they came to occupy and the ‘flow’ between them them are straightforward, core ideas in biology.

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AP Biology DNA Lecture modules RNA What's important about... | Bruce | | Leave a comment

What’s important about… the TCA Cycle

The Kreb’s cycle/TCA cycle/Citric acid cycle is a cornerstone of most introductory biology discussions of energetics. Boy is it scary to look at, but what a wonderful opportunity to make students memorize names and structures! But seriously… short of asking students to know everything about everything, what are the core concepts that they ‘ought’ to understand?

To my mind, two words: energetic electrons

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What's important about... | Bruce | | 1 Comment

New Lecture Components

I’ve made a first stab at adding some lecture component materials (stuff I’ve already researched and collated; note that many of these could be used an in-class exercises or at-home student explorations). These are meant to be collections of inter actives (often simulations or explorations I’ve created), Web and literature resources, and sometimes Powerpoint/Keynotes files and movies from my own lectures.

Yesterday, I made a first pass at Opsin; this joins existing Flu and Cytosine/Uracil/Thymine modules; I also added a bit to the Blue eyes vs. Lactose intolerance set (where we deduce number and timing of origin of human mutations from gene sequence comparison). All are accessible from the link above.

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Problem-Solving Strategies I: Polya

We all want our students to ‘think critically’ and ‘become better problem solvers’. But what does that mean, and how do we scaffold and provide opportunities developing problem-solving strategies? Obviously, this question is deeper and wider than a single blog post, but I wanted to put my first card on the table. First and foremost, this must all begin with ‘legitimate’ problems. To me, this means ones where a student must reach beyond plug-and-play; there must be elements of identifying which information is useful, choosing approaches that attack weak points of the problem, finding their own path rather than following ones already mapped out. Two cases that I think exemplify ‘real’ problems are Petals around the rose and (surprise surprise) my own PatternMaster.

The rest of this introductory post is dedicated to a distillation of George Polya’s advice to young mathematicians

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