The history of biophysics is the history of making physical explanations of life testable. Researchers learned to connect biological behaviour with measurable quantities such as voltage, current, molecular arrangement and force. Instruments mattered because they changed which questions could be answered: an average current, an individual channel opening and a protein structure provide different evidence.
The gold standard is to explain what a historical advance allowed people to measure, what inference followed, and what remained unresolved. This guide follows selected turning points rather than claiming a complete chronology or a single founder. Its calculations and datasets are original teaching examples, not historical measurements, medical advice or instructions for experiments on living subjects.
For the modern subject, start with The Gold Standard of Biophysics. This historical guide belongs to the Gold Standard master and applies the Education parent’s central test: can an explanation still help when the question changes?
Choose your biophysics history route
Chapters 1–3: Read the historical evidence
Chapters 4–6: Measure membrane events
Chapters 7–9: Interpret structures and forces
Chapters 10–12: Compare methods and repair claims
Chapter index
Read the historical evidence · Chapters 1–3
1. Define the historical question before choosing the hero
2. Understand why communities and instruments developed together
3. Turn an electrical signal into a measurable biological problem
Measure membrane events · Chapters 4–6
4. See why controlling voltage changes the question
Interpret structures and forces · Chapters 7–9
7. Follow the move from molecular composition to spatial structure
Compare methods and repair claims · Chapters 10–12
10. Compare mechanical measurements without changing the claim
11. Keep equilibrium measurements separate from dynamic histories
Test transfer and continue learning · Chapters 13–14
CHAPTER 1 OF 14 · Read the historical evidence
1. Define the historical question before choosing the hero
Biophysics connects physical reasoning with biological questions. The history of that connection has several overlapping strands: measuring biological processes, constructing mathematical descriptions, determining molecular structures, developing instruments and organising research communities. These strands do not begin on the same date. A society’s foundation establishes an institution; it does not establish the first occasion on which anyone used physics to study life.
A useful historical question therefore has an object and an evidential standard. “When did researchers measure individual ion-channel currents?” is more precise than “Who discovered electrical life?” The first question can be examined through experimental publications, instrument descriptions and recorded signals. The second compresses many different achievements into a phrase that is difficult to test.
Separate observation, model and mechanism
An observation might be a current trace. A model might describe how that trace varies with voltage and time. A proposed mechanism might involve a membrane protein switching between conducting and nonconducting states. The observation constrains the model, and the model motivates further experiments, but the three are not interchangeable.
Try an original classification exercise. A researcher reports that a signal doubles when the number of cells doubles. Another proposes a formula predicting that relationship. A third identifies a molecular component whose alteration changes the signal. The first supplies a scaling observation, the second a quantitative account and the third a mechanistic intervention. None automatically invalidates the others; they answer different questions.
This distinction makes historical reading more generous and more rigorous. An earlier model can be powerful without containing a later molecular explanation. Conversely, a later image can reveal a structure without explaining every dynamic event. Ask what each investigator could actually observe, which alternatives were available and how much the evidence discriminated between them.
When taking notes, use four sentences: the question, the measurement, the inference and the unresolved alternative. If one sentence is missing, the account may be memorable but incomplete. This method also prevents a modern textbook diagram from being mistaken for the evidence that originally produced it.
CHAPTER 2 OF 14 · Read the historical evidence
2. Understand why communities and instruments developed together
The Biophysical Society’s own records distinguish the First National Biophysics Conference in Columbus in March 1957 from the formal founding of the Society in 1958. Its bylaws describe the intervening organisational work and ratification at the 1958 meeting. These are compatible milestones, not competing answers to an identical question. See the Society’s bylaws and institutional overview.
That small date distinction teaches a larger lesson. Disciplines develop through research practices and institutions as well as through named discoveries. Meetings let people compare unfamiliar methods. Shared terminology helps a physiologist understand a physicist’s instrument. Journals provide places to explain the technical details that make results inspectable. These activities do not guarantee correctness, but they support cumulative criticism.
A collaboration is a chain of dependencies
Imagine a team measuring a tiny biological force. One person understands the specimen, another calibrates the sensor, another models the response and another checks the analysis. If the sensor’s calibration changes, every biological conclusion using that calibration may need revision. The scientific result is therefore more than the last graph or the most visible researcher.
A useful historical account asks which tools, materials and skills made an experiment possible. It also asks who maintained them. A technician’s stable preparation, a mathematical correction or an improved amplifier may be central even when a short award biography does not foreground that contribution. Where the record is incomplete, identify the gap rather than supplying imagined names or motives.
For a study exercise, draw the dependency sequence in words: specimen preparation, controlled intervention, signal detection, calibration, analysis, interpretation. Choose one stage and remove it. Could the team still make the original claim? A detector without calibration might still show that something changed, while losing the ability to state how much it changed. That is a specific loss of knowledge, not merely a less attractive presentation.
Institutional dates should consequently be labelled by what happened. “Conference,” “decision to organise,” “formal founding,” “publication” and “award” are distinct events. Keeping those labels attached prevents a timeline from silently changing its meaning as it moves from one discipline to another.
CHAPTER 3 OF 14 · Read the historical evidence
3. Turn an electrical signal into a measurable biological problem
Hodgkin and Huxley’s 1952 paper connected a quantitative account of membrane current with nerve conduction and excitation. The original publication record identifies the paper, authors and date. Its historical importance lies in linking measurements to a model that could be tested against electrical behaviour, rather than merely describing a nerve as “active.”
A beginner can approach this achievement without reproducing the full model. Voltage is an electrical potential difference. Current is charge movement per unit time. Conductance describes how readily current flows for a specified driving force. In a simple teaching expression, I = g(V − E), where E is the reversal potential for the current being considered. This equation is not the complete Hodgkin–Huxley system.
Worked example: preserve the sign convention
Suppose g = 2 nanosiemens, V = −20 millivolts and E = −70 millivolts. The driving difference is 50 millivolts, so I = 100 picoamperes. The conversion works because a nanosiemens multiplied by a millivolt gives a picoampere. Under the convention used here, the positive sign denotes outward current.
Now change V to −90 millivolts while holding g and E fixed. The difference becomes −20 millivolts and I becomes −40 picoamperes. The current changes direction without requiring the conductance to become negative. That distinction is fundamental: the route can remain available while the driving force reverses.
The assumptions are deliberately restrictive. Real conductance can depend on voltage, time, chemical conditions and channel state. The example isolates driving force so that the learner does not confuse an electrical difference with the availability of a conducting pathway.
For historical reading, inspect the author’s voltage and current conventions before comparing equations with a modern textbook. A changed reference direction can change signs without changing the underlying physical prediction. Repair the conventions first; do not declare a contradiction from one minus sign alone.
CHAPTER 4 OF 14 · Measure membrane events
4. See why controlling voltage changes the question
If a membrane’s voltage changes while its conductance also changes, a current trace mixes several influences. Voltage-clamp reasoning addresses this difficulty by controlling voltage and measuring the current required under that condition. The experimental intervention changes what can be inferred. Instead of simply watching an electrical event unfold, the investigator imposes a condition and studies the response.
This is an important historical pattern: an instrument can separate variables that previously moved together. However, separation is never absolute. The quality of control, electrical access, specimen geometry and recording bandwidth all matter. Calling an experiment “controlled” does not mean every property of the preparation is held fixed.
Worked example: the same current has different explanations
Suppose a measured current has magnitude 100 picoamperes. Model A uses a conductance of 2 nanosiemens and a driving difference of 50 millivolts. Model B uses 5 nanosiemens and 20 millivolts. Both give the same product. The current alone cannot tell you which combination produced it.
Now suppose the driving difference has been independently established as 50 millivolts. Dividing current by that difference gives 2 nanosiemens. The additional information removes an ambiguity that the current measurement could not resolve. This does not establish the molecular identity of the pathway; it improves the electrical inference.
This example illustrates identifiability: whether different explanations can generate the same observations. Adding more decimal places to the current would not solve the original ambiguity. Measuring another relevant quantity would. Precision and identification are different achievements.
A good historical question is therefore, “Which ambiguity did the new method remove?” Another is, “Which ambiguity remained?” An instrument that separates voltage from current may still leave uncertainty about the number of channels, their molecular composition or the preparation’s representativeness. The next advance does not make the previous one meaningless; it changes the level at which an explanation can be tested.
When reading any graph, write down what was imposed, what was measured and what was calculated. This simple separation is often more useful than immediately trying to memorise the curve’s name.
CHAPTER 5 OF 14 · Measure membrane events
5. Connect average currents with individual events
Single-channel recording provided a new level of evidence about membrane function. Neher’s 1991 Nobel lecture discusses the relationship between earlier conductance descriptions and channel research. The 1991 Nobel award record recognises Neher and Sakmann’s work on the function of individual ion channels.
The conceptual change is easiest to understand through an original counting model. Suppose a preparation contains N identical, independent channels. Each open channel carries current i under fixed conditions. If the fraction of time spent open is P, the mean current is N × i × P. This is a simplified model; actual populations can contain multiple channel types, correlated behaviour and additional states.
Worked example: equal means, different populations
Population A has 100 channels, each carrying 2 picoamperes when open, with an open probability of 0.1. Its mean current is 20 picoamperes. Population B has 20 channels with the same individual current and an open probability of 0.5. Its mean current is also 20 picoamperes.
An average measurement does not distinguish these populations. An observation that resolves individual events can supply information about event size and timing. An independent estimate of channel number can help further. The point is not that an average is useless; it is that averaging discards some distinctions.
A practical analogy is a classroom attendance total. Twenty occupied seats could mean twenty people stayed throughout or many people entered and left. The average occupancy does not contain the complete history of individual movements. Likewise, a smooth electrical trace need not imply a continuously variable process at every microscopic component.
The diagnostic question is: “Which microscopic arrangements share this average?” Write down at least two before claiming that a mean identifies a unique mechanism. This exercise prepares the reader to appreciate why a new measurement scale could transform a longstanding biological problem.
CHAPTER 6 OF 14 · Measure membrane events
6. Learn what noise and bandwidth can hide
Resolving a small event requires more than enlarging a graph. Noise can obscure it, filtering can smooth it and insufficient sampling can miss it. This is why the history of sensitive biological measurements is also a history of controlling the measurement system. A biological interpretation depends on what the instrument could distinguish.
Consider an invented channel trace. An opening produces a 2-picoampere step. In one recording, typical baseline fluctuations are around 0.2 picoamperes; in another, they are around 2 picoamperes. The step is much easier to recognise in the first recording. This comparison is illustrative rather than a formal statistical detection rule, because detectability also depends on the noise spectrum, event duration and analysis method.
Worked example: a short event can vanish
Suppose an instrument reports only a mean over each 10-millisecond interval. A 2-picoampere event lasting 1 millisecond, with zero current during the remaining 9 milliseconds, contributes an interval mean of 0.2 picoamperes. The event has not become physically weaker. The reporting method has diluted it in time.
This explains why “no event was visible” is not always equivalent to “no event occurred.” A defensible negative claim should specify the range of event sizes and durations that the method could detect. If the relevant events fall outside that range, the experiment may not discriminate between absence and invisibility.
There is a tradeoff. Smoothing can make a stable trend easier to estimate while erasing brief transitions. Preserving high-frequency information can retain fast events while exposing more noise. The appropriate choice depends on the question, not on which trace looks most orderly.
To repair a weak interpretation, ask for the acquisition conditions, filtering, detection criteria and an appropriate control. Do not reconstruct invisible events simply because a preferred theory predicts them. Historical instrument limitations deserve the same care: we should neither mock an earlier method for lacking later sensitivity nor attribute later resolution to an older trace.
CHAPTER 7 OF 14 · Interpret structures and forces
7. Follow the move from molecular composition to spatial structure
Protein crystallography brought another kind of physical evidence into biology. The MRC Laboratory of Molecular Biology’s account of Kendrew and Perutz describes their work on myoglobin and haemoglobin and the 1962 Chemistry Nobel recognition. The achievement connected biological molecules with experimentally constrained three-dimensional arrangements.
A list of components does not determine their arrangement. Knowing that a building contains beams and panels is different from knowing where those parts sit. Similarly, a protein’s composition or sequence and its spatial structure are related but distinct kinds of information. Structure can help explain how interactions are possible, while dynamics and biochemical conditions still matter.
A structure is an inference from evidence
A diffraction pattern is not a conventional photograph of a molecule. Measured intensities are used, together with additional information and modelling, to infer a structural account. The result must be judged against the evidence and the limits of the experiment. The existing X-ray Crystallography guide develops that distinction in detail.
For an original thought experiment, imagine two arrangements containing the same number of identical pieces. In one, the pieces form a compact cluster; in the other, they form an extended chain. Counting the pieces cannot distinguish the arrangements. A measurement sensitive to spatial organisation can. But its resolving power determines which differences are distinguishable.
This is why a historical milestone should state the resolution and kind of structural claim where those details matter. A coarse shape, a fold and a detailed atomic model are not synonyms. Later refinement can add information without making the earlier broad arrangement worthless.
A misleading sentence would be, “Once scientists saw the protein, they knew how it worked.” A better question is, “Which functional possibilities did the structure support or rule out, and what additional experiments tested them?” This keeps structure connected to biology while avoiding the assumption that one static representation contains an entire living process.
CHAPTER 8 OF 14 · Interpret structures and forces
8. Use scale and uncertainty to read an image responsibly
Images are persuasive because they make an unfamiliar object feel visible. Biophysical history teaches a more careful habit: ask how a displayed feature relates to a measurement. A colour can encode an analysis choice. A surface can be generated from a model. An apparent boundary can depend on resolution and processing. These facts do not make the image false; they define how it should be read.
Worked example: precision is not accuracy
Suppose two methods estimate the same distance. Method A reports 10.00 nanometres on repeated trials, but its calibration is systematically 10 percent high. Method B reports values around 9.1 nanometres with visible variation and a well-checked calibration. Method A’s repeated decimal places do not establish that its estimate is closer to the true distance.
If A’s reading equals 1.10 times the true distance, a reported 10.00 corresponds to approximately 9.09 nanometres after correction. The calculation is 10.00 divided by 1.10. Simply subtracting 10 percent of the reported value would give 9.00 and would apply a different mathematical operation.
The assumptions must travel with that correction. A uniform multiplicative calibration error is not the same as a fixed offset. If the instrument instead adds 1 nanometre to every measurement, subtraction is appropriate. Before correcting a historical dataset, establish which error model is justified.
This example is a modern teaching exercise, not an allegation about any named historical result. Its purpose is to make calibration visible as part of knowledge. A beautifully reproducible instrument can reproduce the same systematic error.
For a practical reading route, label every number as observed, calibrated, calculated or assumed. Then ask which conclusion would change if the calibration shifted. A robust qualitative finding may survive while a precise quantitative claim changes. Historical accounts become clearer when they distinguish those levels rather than treating every revision as either total vindication or total failure.
CHAPTER 9 OF 14 · Interpret structures and forces
9. Understand why manipulating a molecule adds evidence
Observation tells us how a system behaves under the conditions present. Manipulation changes a condition and asks how the system responds. Optical tweezers made controlled physical interactions with very small objects possible through light. The Royal Swedish Academy of Sciences’ 2018 announcement describes Ashkin’s contribution and its biological applications, including the 1987 trapping of living bacteria.
The historical importance is not that light became a magical hand. A calibrated physical interaction created new experimental questions. How does an object move under an applied force? Does it recover when that force changes? Are responses consistent between repeated trials? Interpretation still depends on the specimen, coupling and calibration.
Worked example: displacement becomes a force estimate
Within a suitable approximately linear operating region, treat a trap as a spring with stiffness k. Suppose k = 0.05 piconewtons per nanometre and a tracked bead is displaced 40 nanometres from the trap centre. The restoring-force magnitude is approximately kx = 2 piconewtons.
Now suppose the stiffness estimate is revised to 0.04 piconewtons per nanometre. The same displacement implies 1.6 piconewtons. Nothing about the visible position needed to change. The interpretation changed because the calibration connecting position to force changed.
This spring relation is a limited model, not a universal description of every optical arrangement or every displacement. It does not establish the force experienced by a particular biological component unless the connection between that component and the tracked object is understood. Nor does trapping without obvious immediate harm prove that every biological property remains unaffected.
The learning question is therefore, “What connects the thing I can measure to the thing I want to know?” Sometimes the connection is direct; often it includes a model, a calibration and a physical attachment. Biophysical advances become trustworthy when that chain can be inspected rather than hidden behind an impressive instrument name.
CHAPTER 10 OF 14 · Compare methods and repair claims
10. Compare mechanical measurements without changing the claim
Two instruments can investigate the same cell while reporting different quantities. One may measure displacement under a local force; another may measure a shape change under pressure. Their results cannot be compared merely because both are described as “stiffness.” Geometry, time scale, contact conditions and the assumed material model affect what the number means.
The existing specialist article on micropipette aspiration and cell-mechanics evidence is useful here. It separates applied suction, observed shape and inferred mechanical properties. That separation is part of the historical movement from qualitative descriptions of biological form toward controlled physical tests.
Worked example: geometry changes an apparent response
Consider two ideal springs, not real cells. Spring A has stiffness 0.10 newtons per metre; spring B has stiffness 0.20 newtons per metre. Under a force of 0.002 newtons, their extensions are F/k: 0.020 metres and 0.010 metres respectively. In this limited example, B extends half as much under the same force.
Now suppose two real specimens extend by those amounts. Can we immediately conclude that their biological materials differ by a factor of two? No. The specimens might differ in thickness, length, attachment or internal organisation. A whole-object stiffness is not automatically an intrinsic material property.
This distinction helps explain why a new apparatus does not simply replace an older one. Different methods may probe different scales or modes of deformation. Agreement can strengthen an interpretation when the quantities are made comparable. Disagreement can reveal a hidden assumption or a real dependence on measurement conditions.
A useful comparison paragraph states the loading condition, the measured response, the geometric model and the time interval. If these are missing, “twice as stiff” is incomplete. Do not convert it into a universal biological ranking. The same discipline applies to historical comparisons: preserve what the original apparatus actually constrained before translating its result into modern terminology.
CHAPTER 11 OF 14 · Compare methods and repair claims
11. Keep equilibrium measurements separate from dynamic histories
Biophysics also examines how molecules associate and how their populations change. An equilibrium measurement and a time-resolved measurement answer different questions. A final distribution can be the same even when the routes and rates leading to it differ. This distinction helps readers understand why additional methods were valuable even after a system’s average behaviour was known.
Consider two hypothetical rooms with 50 people each. In one, nobody moves. In the other, people continually enter and leave at equal rates. The occupancy is unchanged in both rooms, but their dynamics are different. A single count cannot distinguish these histories. A time-resolved observation can.
Worked example: total concentration is not free concentration
Suppose a teaching mixture contains 10 micromoles per litre of ligand in total. If 6 micromoles per litre are bound in complexes, the free concentration is 4 micromoles per litre. A model that requires free ligand should use 4, not 10. The subtraction is simple; identifying which quantity an equation requires is the essential reasoning step.
The ligand-depletion specialist guide develops this mass-balance issue. It is a useful continuation because it shows how an apparently small naming mistake can change an inferred molecular property.
Now imagine a second mixture also has 4 micromoles per litre free ligand but reaches that state much faster. The matching final free concentration does not prove matching association and dissociation rates. To investigate the rates, one needs observations that retain temporal information and a model appropriate to the process.
This chapter is not assigning a single historical discovery date to equilibrium or kinetics. It identifies a recurring distinction that makes the history intelligible. New methods often mattered because they recovered information that an earlier measurement deliberately averaged away. The right question is not whether one method is more modern, but whether it observes the distinction needed for the claim being made.
CHAPTER 12 OF 14 · Compare methods and repair claims
12. Diagnose misleading accounts of scientific progress
A short history often becomes a sequence of winners: one person discovers a fact, another improves it and a final technology solves the problem. That format is easy to remember but can distort how evidence accumulates. Different researchers may address different scales, and later explanations can depend on earlier measurements that remain valuable.
Repair four common shortcuts
“An award date is the discovery date.” Repair it by identifying the publication, experimental milestone and award separately. The 1962 protein-structure prize and the 1991 single-channel prize are recognition events. They should not be used as automatic dates for every experiment associated with the laureates.
“The model predicted a curve, so its mechanism was proved.” Repair it by considering alternative models and new conditions. A successful fit constrains explanation, but multiple mechanisms can sometimes generate similar curves. Predictions outside the fitting conditions are particularly informative when the relevant assumptions remain applicable.
“The instrument is more sensitive, so the conclusion is more general.” Repair it by distinguishing sensitivity from representativeness. Measuring one component in detail can answer a microscopic question without showing that all cells or organisms behave the same way. Sampling and preparation still limit generalisation.
“Earlier researchers were wrong because they lacked today’s vocabulary.” Repair it by translating the question and evidence before judging the conclusion. An older term may cover several modern concepts, while a modern label may imply distinctions unavailable to the original investigators. Explain the mismatch rather than silently rewriting the record.
A practical diagnostic is to remove the names from a paragraph and ask whether the evidential reasoning remains. If nothing remains except a date and a celebration, add the measurement and the unresolved question. Then restore the names with appropriate credit. This produces history that honours people by explaining their work rather than treating their biographies as substitutes for the work.
The aim is not to eliminate narrative. It is to build a narrative whose turning points are changes in what could be known, measured or tested.
CHAPTER 13 OF 14 · Test transfer and continue learning
13. Test transfer with a changed-context research claim
A fictional team reports that a treatment “makes a cell’s channels stronger.” The mean recorded current rises from 20 to 40 picoamperes. The report supplies no individual-channel recordings, no independent channel count and no confirmation that the driving force stayed unchanged. What does the observation establish?
It establishes a doubled mean current under the reported measurement conditions. It does not yet identify the cause. Using the simple expression N × i × P, the increase could reflect more channels, a larger individual current, a higher open probability or a combination. Changes in recording quality or driving force could also affect interpretation.
Work through two explanations
Before treatment, suppose N = 100, i = 2 picoamperes and P = 0.1. The mean is 20 picoamperes. Explanation A doubles P to 0.2, giving 40 picoamperes. Explanation B doubles N to 200 while keeping the other values unchanged, also giving 40 picoamperes. The measured mean alone cannot choose between them.
What additional observation would help? Single-channel event amplitudes and timing could address some possibilities; an independent count could address others. The method should be chosen for the ambiguity. Repeating the same mean measurement with more decimal places may improve precision while leaving the central causal question unresolved.
Now change the context. The team reports a force increase inferred from a tracked bead instead of an electrical current increase. The specific equation changes, but the reasoning transfers. Check whether displacement, calibration, coupling or the biological process changed. Do not carry the channel-count equation into mechanics; carry the habit of separating the observation from the inferential chain.
The strongest defensible answer is conditional: “The recorded mean increased; these mechanisms remain possible; this next measurement would distinguish them under these assumptions.” That answer is more useful than either accepting the team’s preferred explanation or dismissing all measurement as uncertain. It identifies what is known and makes the next question concrete.
CHAPTER 14 OF 14 · Test transfer and continue learning
14. Build a learning route and read the sources critically
Do I need advanced mathematics to begin?
No. Begin by identifying quantities, units, controlled conditions and alternative explanations. The examples here use multiplication, division and simple averages. More advanced study requires additional mathematics, but basic reasoning can already expose an invalid comparison or an unsupported claim. Learn the mathematics alongside a question it helps answer.
Is biophysics simply physics applied to the human body?
That is too narrow. Biological questions can concern molecules, membranes, cells, tissues and organisms, including systems that are not human. The physical approach becomes useful when the variables and measurements match the biological question. The modern Biophysics root offers a broader subject route.
Does a molecular structure explain function completely?
It can constrain possible mechanisms, but function also depends on interactions, conditions and dynamics. Pair a structural claim with a functional question and ask what experiment connects them. Continue through X-ray Crystallography when the main difficulty is understanding how diffraction evidence becomes a model.
How should I study a primary paper?
First identify its question and the actual measured quantities. Then read one figure with its caption, units and experimental conditions. Write an alternative explanation the experiment addresses and one it leaves open. Finally compare your interpretation with the authors’ stated conclusion. You do not need to understand every technical detail on the first reading, but you should know which details your own claim depends on.
Which sources support the historical landmarks?
Use the Biophysical Society’s institutional history and bylaws for the conference and founding distinction. Use Hodgkin and Huxley’s 1952 paper for the quantitative membrane-current landmark. The MRC LMB account supplies institutional context for the protein-structure work; Neher’s lecture provides a researcher’s account of channel studies. The Royal Swedish Academy’s 2018 announcement supports the optical-tweezers landmark. These sources have different purposes: a paper, a retrospective lecture and an award announcement should not be treated as identical forms of evidence.
For the measurement models, compare the physiological society’s channel-fluctuation tutorial with the Stanford Block Lab explanation of optical tweezers. The former makes the relationship between channel number, individual current and opening probability explicit; the latter explains the optical spring and the importance of calibration.
What should I do next?
Choose one mechanism and write a one-page explanation containing a measurement, an equation if appropriate, a worked example and a limitation. Change one assumption and check the result again. For related history, continue with History of Molecular Biology. For practical explanations across subjects, use the How X Works hub. Return to the Gold Standard master to choose another field.