The United States and China hold the best hope for leading a global economic recovery, yet they may lack sufficient strength to firmly pull the world out of recession.

President Barack Obama warned fellow world leaders at the Group of 20 summit in London that they should not count on "voracious" U.S. consumers generating the level of demand that helped drive eight years of strong global economic growth.

But without an obvious growth engine to replace flagging American consumption, the global economy appears headed for a prolonged slump followed by only a tepid rebound.

"It is going to be a difficult paradox for the world, with the economy at the epicenter of the crisis -- the United States -- still being seen as the savior of the world at large," said Eswar Prasad, a senior fellow at the Brookings Institution.

The Democratic-controlled U.S. Congress on Thursday approved budget blueprints embracing President Barack Obama's agenda but leaving many hard choices until later and a government deeply in the red.

With no Republican support, the House of Representatives and Senate approved slightly different, less expensive versions of Obama's $3.55 trillion budget plan for fiscal 2010, which begins on October 1. The differences will be worked out over the next few weeks.

Obama, who took office in January after eight years of the Republican Bush presidency, has said the Democrats' budget is critical to turning around the recession-hit U.S. economy and paving the way for sweeping healthcare, climate change and education reforms he hopes to push through Congress this year.

Obama, traveling in Europe, issued a statement praising the votes as "an important step toward rebuilding our struggling economy." Vice President Joe Biden, who serves as president of the Senate, presided over that chamber's vote.

The Democratic-controlled U.S. Congress on Thursday approved budget blueprints embracing President Barack Obama's agenda but leaving many hard choices until later and a government deeply in the red.

With no Republican support, the House of Representatives and Senate approved slightly different, less expensive versions of Obama's $3.55 trillion budget plan for fiscal 2010, which begins on October 1. The differences will be worked out over the next few weeks.

Obama, who took office in January after eight years of the Republican Bush presidency, has said the Democrats' budget is critical to turning around the recession-hit U.S. economy and paving the way for sweeping healthcare, climate change and education reforms he hopes to push through Congress this year.

Obama, traveling in Europe, issued a statement praising the votes as "an important step toward rebuilding our struggling economy." Vice President Joe Biden, who serves as president of the Senate, presided over that chamber's vote.

Enzymes are generally globular proteins and range from just 62 amino acid residues in size, for the monomer of 4-oxalocrotonate tautomerase, to over 2,500 residues in the animal fatty acid synthase. A small number of RNA-based biological catalysts exist, with the most common being the ribosome; these are referred to as either RNA-enzymes or ribozymes. The activities of enzymes are determined by their three-dimensional structure. However, although structure does determine function, predicting a novel enzyme's activity just from its structure is a very difficult problem that has not yet been solved.

Most enzymes are much larger than the substrates they act on, and only a small portion of the enzyme (around 3–4 amino acids) is directly involved in catalysis. The region that contains these catalytic residues, binds the substrate, and then carries out the reaction is known as the active site. Enzymes can also contain sites that bind cofactors, which are needed for catalysis. Some enzymes also have binding sites for small molecules, which are often direct or indirect products or substrates of the reaction catalyzed. This binding can serve to increase or decrease the enzyme's activity, providing a means for feedback regulation.

Like all proteins, enzymes are made as long, linear chains of amino acids that fold to produce a three-dimensional product. Each unique amino acid sequence produces a specific structure, which has unique properties. Individual protein chains may sometimes group together to form a protein complex. Most enzymes can be denatured — that is, unfolded and inactivated — by heating or chemical denaturants, which disrupt the three-dimensional structure of the protein. Depending on the enzyme, denaturation may be reversible or irreversible.

The underlying causes leading to the crisis had been reported in business journals for many months before September 2008, with commentary about the financial stability of leading U.S. and European investment banks, insurance firms and mortgage banks consequent to the subprime mortgage crisis.

Beginning with failures caused by misapplication of risk controls for bad debts, collateralization of debt insurance and fraud, large financial institutions in the United States and Europe faced a credit crisis and a slowdown in economic activity. The impacts rapidly developed and spread into a global shock resulting in a number of European bank failures and declines in various stock indexes, and large reductions in the market value of equities and commodities. The credit crisis was exacerbated by Section 128 of the US Emergency Economic Stabilization Act of 2008 which allowed the Federal Reserve to pay interest on excess reserve requirement balances held on deposit from banks, removing the incentive for banks to extend credit instead of placing cash on deposit with the Fed. Moreover, the de-leveraging of financial institutions further accelerated the liquidity crisis and caused a decrease in international trade. World political leaders, national ministers of finance and central bank directors coordinated their efforts to reduce fears, but the crisis continued. At the end of October a currency crisis developed, with investors transferring vast capital resources into stronger currencies such as the yen, the dollar and the Swiss franc, leading many emergent economies to seek aid from the International Monetary Fund.

Enzymes are generally globular proteins and range from just 62 amino acid residues in size, for the monomer of 4-oxalocrotonate tautomerase, to over 2,500 residues in the animal fatty acid synthase. A small number of RNA-based biological catalysts exist, with the most common being the ribosome; these are referred to as either RNA-enzymes or ribozymes. The activities of enzymes are determined by their three-dimensional structure. However, although structure does determine function, predicting a novel enzyme's activity just from its structure is a very difficult problem that has not yet been solved.

Most enzymes are much larger than the substrates they act on, and only a small portion of the enzyme (around 3–4 amino acids) is directly involved in catalysis. The region that contains these catalytic residues, binds the substrate, and then carries out the reaction is known as the active site. Enzymes can also contain sites that bind cofactors, which are needed for catalysis. Some enzymes also have binding sites for small molecules, which are often direct or indirect products or substrates of the reaction catalyzed. This binding can serve to increase or decrease the enzyme's activity, providing a means for feedback regulation.

Like all proteins, enzymes are made as long, linear chains of amino acids that fold to produce a three-dimensional product. Each unique amino acid sequence produces a specific structure, which has unique properties. Individual protein chains may sometimes group together to form a protein complex. Most enzymes can be denatured — that is, unfolded and inactivated — by heating or chemical denaturants, which disrupt the three-dimensional structure of the protein. Depending on the enzyme, denaturation may be reversible or irreversible.

If I speak in the tongues of men and of angels, but have not love, I am only a resounding gong or a clanging cymbal. If I have the gift of prophecy and can fathom all mysteries and all knowledge, and if I have a faith that can move mountains, but have not love, I am nothing. If I give all I possess to the poor and surrender my body to the flames, but have not love, I gain nothing. Love is patient, love is kind. It does not envy, it does not boast, it is not proud. It is not rude, it is not self-seeking, it is not easily angered, it keeps no record of wrongs. Love does not delight in evil but rejoices with the truth. It always protects, always trusts, always hopes, always perseveres. Love never fails. But where there are prophecies, they will cease; where there are tongues, they will be stilled; where there is knowledge, it will pass away. For we know in part and we prophesy in part, but when perfection comes, the imperfect disappears. When I was a child, I talked like a child, I thought like a child, I reasoned like a child. When I became a man, I put childish ways behind me. Now we see but a poor reflection as in a mirror; then we shall see face to face. Now I know in part; then I shall know fully, even as I am fully known. And now these three remain: faith, hope and love. But the greatest of these is love.