Given current trends in risk factors, what are likely to be the major cause of death and disability in low- and middle-income countries in the 2020s and beyond? Which policies and actions taken over the next decade at national and international levels could influence these trends, and which factors might facilitate their implementation

many other transport proteins, often called pumps, move materials against a concentration gradient. active transport drives molecules across a membrane from a region of lower concentration to a region of higher concentration. this process, shown in figure 5.1, uses transport proteins powered by chemi- cal energy.

hydrogen is a compound or a single element and a element is a pure substence that cannot be separated into simpler subtances

clorine is a compound its a chemical substance that forms when two or more different elements combine

so both hydrogen and clorine are compounds