Enzymes catalyze all the reactions of life. They're what allow you to extract materials and energy from your environment and turn that into muscle and tissue and fat. That's all done by enzymes. They're pretty remarkable chemists - they're even better than Caltech chemists.

I wanted to make enzymes that would solve human problems, not just problems for a cell that makes them.

The code of life is like a Beethoven symphony. We have not yet learned how to write music like that. But evolution does it very well. I am learning how to use evolution to compose new music.

Microbes such as bacteria and yeast use enzymes to make fuels from biomass. We use directed evolution to perfect those enzymes and make new fuels efficiently.

Evolution is good for optimising and that is well understood. But evolution also creates things that no one knew were even possible.

In the test tube, I can make any DNA I want, recombining it from monkeys, worms, anywhere. So I can explore new rules of breeding with molecules.

I took mechanical drawing, geometry and typing at high school, the latter because that is what they did with smart girls in those days!

I wanted to rewrite the code of life, to make new molecular machines that would solve human problems.

Bemoaning your fate is not going to solve the problem.

Human beings have been manipulating the biological world for thousands of years without understanding how DNA codes function.

I love what I do, and I'm grateful for every day I can do it.

I know how to do science. I know how to make things. I don't know how to run a company. Now that's a really tough job.

I'm interested in using evolution to move forward into the future, to get biology to do a lot of new chemistry for us.

We all need friends, and friends are there to hold you up when nothing else can.

Isobutanol is not a natural product, but we evolved an enzyme that makes it possible to convert plant sugars to this precursor to jet fuel.

Evolution, to me, is the best designer of all time.

I tried lots of things and never stopped learning.

I was used to being the only woman in everything... I didn't even think about it. Men were my role models - there's nothing wrong with that.

For some reason, there are political forces that somehow feel threatened by honest inquiry. How can you be threatened by wanting to know the facts?

Only engineers would do something like random mutagenesis.

Cellulose has physical and chemical properties that make it difficult to access and difficult to break down.

Using the power of protein engineering and evolution, we can convince enzymes to take what they do poorly and do it really well.

This innovation machine that's evolution, we can use it to do all sorts of interesting things.

Silicon is all around but it's tied up in rocks... with these very strong silicon-oxygen bonds that living systems would have to break in order to use silicon.

I'd like to see what fraction of things that chemists have figured out we could actually teach nature to do. Then we really could replace chemical factories with bacteria.

What I find most interesting is what nature can do if you only ask.

The real frontier is making these hybrid systems where you expand the capabilities of biology with chemistry.

Inside of a living cell there are thousands of proteins that enable it to make more of itself and make your malaria drug, for instance. We don't understand those. We don't understand how they work together.

We're seeing a move toward making things that either chemistry cannot make or can't make efficiently but biology does.

My whole interest is, how do you use evolution as an innovation engine? How does evolution solve new problems that life faces? And to have a system that can create a whole new chemical bond that biology hasn't done before, to me, demonstrates the power of nature to innovate.

People are really interested in these fundamental questions: Why is life based on carbon and not silicon?

Silicon-based life on Earth doesn't make sense, but perhaps it would in some totally different environment.

Enzymes are masters of chemistry. They evolved over billions of years to perform specific biological functions. They make complex materials with virtually no waste.

In the universe of possibilities that exist for life, we've shown that it is a very easy possibility for life as we know it to include silicon in organic molecules. And once you can do it somewhere in the universe, it's probably being done.

My laboratory uses evolution to design new enzymes. No one really knows how to design them - they are tremendously complicated. But we are learning how to use evolution to make new ones, just as nature does.

The biological world always seems poised to innovate.

Mangroves, salt marshes and sea grass lock away carbon at up to five times the rate of tropical forests.

Pollution from human activities is changing the Earth's climate. We see the damage that a disrupted climate can do: on our coasts, our farms, forests, mountains, and cities. Those impacts will grow more severe unless we start reducing global warming pollution now.

Wind and other clean, renewable energy will help end our reliance on fossil fuels and combat the severe threat that climate change poses to humans and wildlife alike.

When we go to the store, we bring home more than food - we bring home traces of broader environmental problems. But we can use our shopping carts and dinner plates to help solve some of those problems.

Shell has poured billions of dollars into offshore Arctic drilling, but no matter how much it spends, it cannot make the effort anything but a terrifying gamble. And if Shell, the most profitable company on Earth, can't buy its way to safety in Alaska, nobody can.

Opening up Atlantic and Arctic waters to drilling would lock the next generation into burning oil and gas in a way that only makes climate change that much worse, fueling ever rising seas, widening deserts, withering drought, blistering heat, raging storms, wildfires, floods and other hallmarks of climate chaos.

Carbon pollution contributes to climate change, which causes temperatures to rise. Hotter temperatures mean more smog in the air, and breathing smog can inflame deep lung tissue. Repeated inflammation over time can permanently scar lung tissue, even in low concentrations.

Safer chemicals and more energy-efficient technologies can provide cooling without severe climate implications. Shifting to these alternatives could avoid the equivalent of 12 times the current annual carbon pollution of the United States by 2050.

Mercury is most commonly recognized as a developmental toxin, threatening to young children and fetuses as they develop their nervous system. Prenatal exposure to even low levels of mercury can cause life-long problems with language skills, fine motor function, and the ability to pay attention.

Many environmental battles are won by delaying a destructive project long enough to change the conversation - to allow new economic, political and social dynamics to emerge.

The signs of climate change are visible across the nation, from the drought-stricken fields of Central California to the flooded streets of Michigan. Extreme weather is turning people's lives upside down and costing communities millions of dollars in damaged infrastructure and added health care costs.

Getting toxic lead out of gasoline, the oil industry shouted, would cost a dollar a gallon. It turned out to cost just a penny a gallon to protect hundreds of thousands of kids from lead-induced brain damage.

I do believe that the coal industry sees the cultural shift toward cleaner energy and global warming solutions as a threat to their interests.

From reinforcing beaches in the Rockaways to installing generators at the Coney Island Houses and sealing holes in the subway system, New York is fortifying our ability to withstand future storm surges.