Select the true statements about secondary structure
a) in a β-pleated sheet, the side chains extend above and below the sheet
b) in an α-helix, the side chains are located inside the helix
c) the α-helix is held together by hydrogen bonds between the amide n-h and c=o groups
d) the secondary level of protein structure refers to the spatial arrangements of short segments of the protein
e) peptide bonds stabilize secondary structure

Every compound can be represented by a chemical formula. a chemical formula is the set of symbols showing the elements that make up a compound and their proportions. water’s chemical formula is h 2 2 o. that means a molecule of water contains two atoms of hydrogen and one atom of oxygen chemically bonded. a molecule is a group of two or more atoms bonded together. molecules can range in size from two to thousands of atoms. a molecule of a compound is the smallest unit of that compound. every molecule of water has all the physical and chemical properties of water. that’s because every molecule of water is made of the same elements in the same proportions: two hydrogen atoms and one oxygen! which of the following is a true statement? a every molecule of the same compound will have different properties. b every molecule of a compound has the same proportion of elements. c molecules can be physically separated into smaller units of a compound. d molecules cannot be represented by chemical formulae.

Which organisms have pharyngeal arches that develop from all three germ layers and go through the same development stages as embryos? 1.bird 2.ladybug 3.starfish 4.snake

In what layer of the sun is energy transfers between atoms