Most enzymes are proteins. Many cells make and use an enzyme called catalase to facilitate the decomposition of hydrogen peroxide (H2O2). The products of the decomposition are hydrogen (H2) and oxygen (O2). Stephanie is investigating the structure and function of catalase, and she is comparing catalase to other proteins. What can Stephanie predict will distinguish the structure of catalase from the structures of the other proteins she is studying? A. many regions made entirely of hydrogen and oxygen B. the chemical properties of the peptide bonds C. the types of amino acids it contains D. the sequence of amino acids it contains

Specialized cells which perform a particular function form : organisms organs tissues

On a recent expedition to a remote region of northern canada, scientists uncovered skeletal remains from about 100,000 years ago. surprisingly, all the skeletal remains, which included many species from differing biological families and spanned about two thousand years, showed evidence of experiencing temperatures in excess of 1000 degrees fahrenheit (or 538 degrees celsius). which of the following, if true, best explains the apparent paradox between the cold environment and the evidence of the bones experiencing hot temperatures? (a) chemical changes that naturally occur during the process of decay in only one north canadian species produce the same evidence of the species' skeletons being exposed to hot temperatures as the expedition scientists found. (b) a little over 103,000 years ago, a large fire is known to have occurred in northern canada. (c) strong evidence exists that as early as 70,000 years ago, homo sapiens around the world relied heavily on fire to cook animals. (d) in the same expedition and in roughly the same layer of excavation, scientists found rudimentary wood cutting and hunting tools used by early humans.

Plants consume most of their carbon from a. the soil b. the water c. the roots d. the air