Answer:When the energy from the Sun hits a chloroplast and the chlorophyll molecules, light energy is converted into the chemical energy. Plants use water, carbon dioxide, and sunlight to make sugar and oxygen.
Explanation:
There's been a lot of bad news for polar bears recently. In 2007, for example, scientists reported that if global warming continues unabated, the population could drop two-thirds by 2050.
Answer:
tertiary; quaternary
Explanation:
The orientation of all the atoms of a protein in three dimensions represents its tertiary structure. It includes the folding of the polypeptide chains in a way that brings are far apart amino acids of its secondary structure close together. Various segments of a polypeptide chain interact to form tertiary structures and these segments are held together by different kinds of weak interactions.
However, disulfide cross-links between the segments of polypeptide chains also stabilize the tertiary structure of some proteins. Likewise, disulfide bonds also hold the protein subunits of some proteins together and thereby, contribute to the quaternary structure. For example, two light chains of an antibody are joined together by disulfide bonds.
