Which is not needed for facilitated diffusion? a: ATP
b: protein channels
c: concentration gradient

Consider the skeleton. which skeletal system is represented by the shaded portion of the skeleton? spongy skeleton compact skeleton axial skeleton appendicular skeleton

You have just sequenced a new protein found in mice and observe that sulfur-containing cysteine residues occur at regular intervals. what is the significance of this finding? it will be important to include cysteine in the diet of the mice. cysteine residues are required for the formation of α helices and β pleated sheets. cysteine residues are involved in disulfide bridges that form tertiary structure. cysteine causes bends, or angles, to occur in the tertiary structure of proteins.

Which of the following statements is accurate about evolution? question 10 options: natural selection only eliminates odd individuals. evolution means that a population never has changes in its genetic frequencies. mutations are always harmful. evolution means that a population undergoes changes in its gene frequencies over time.