$23)$ Which statements regarding proteins are true? $($Mark all that apply$)$

a$.$ Peripheral proteins extend all the way across plasma membranes and function as channels.

b$.$ Human proteins can be composed of $10$ different amino acids.

c$.$ Proteins are too large to passively move through plasma $($cell$)$ membranes.

d$.$ Amino acids are linked by peptide bonds in a protein.

e$.$ Enzymes are important proteins that catalyze metabolic reactions by lowering the activation energy $($Ea$).$