The role of enzymes in biological systems is to catalyze chemical reactions. in 1894, chemist emil fischer proposed the lock and key analogy of enzyme action. this analogy explains the specific action of an enzyme with a single substrate. compare the two models seen here. how do they both represent the lock and key analogy?

What was the land like over 500 million years ago? what was under the sea?

Several bodily responses are described below. for each response, determine what caused the change in homeostasis. body starts to sweat breathing rate increases amount of saliva produced changes body starts to shiver

Suppose a point mutation, such as a change from an adenine to a guanine, occurs in the genome of a human sperm cell. the mutation could occur in any region of a gene. the effect of the mutation on the phenotype of the offspring will be determined by where the mutation occurs and its effect on the final gene product. in which of the following scenarios could the mutation alter the phenotype of the offspring? select all of the scenarios that apply the mutation occurs in the promoter and affects the rate of gene transcription. the mutation results in a new, dominant allele the mutation occurs in a portion of an intron not responsible for exon splicing the mutation occurs in a gene that controls development and alters differentiation of a cell type during development. the mutation occurs in a codon and alters the function of the final protein e mutation occurs in a codon, and the amino acid sequence of the final protein is unchanged.