Which level of protein structure is a spatial arrangement of the secondary structure?

typically, most spiders possess eight eyes. however, others have as many as 12, and some don't have any. these eyes are for detecting light from dark, deciphering shapes and for gathering their prey.

amber has allowed scientists to study dna that has been preserved over millions of years.

enzyme active site and substrate specificity

enzymes bind with chemical reactants called substrates. there may be one or more substrates for each type of enzyme, depending on the particular chemical reaction. in some reactions, a single-reactant substrate is broken down into multiple products