What causes fats to be unsaturated?

Question

What causes fats to be unsaturated? Describe the four levels of protein shape and why it's important?

Answer 1

A fat is considered "unsaturated" when it contains one or more double bonds between the carbon atoms in its fatty acid chain. The presence of these double bonds creates kinks in the structure, which makes them take up more space than a chain without double bonds would (a "saturated" fat). This prevents the molecules from packing tightly together, making them liquid at room temperature rather than solid.

The four levels of protein structure are primary, secondary, tertiary, and quaternary.

1. Primary structure refers to the specific sequence of amino acids in a polypeptide chain, which are all linked together by peptide bonds. This structure is important because it determines the protein's unique properties and functions.
2. Secondary structure refers to localized, repeated patterns within the polypeptide chain, such as alpha-helices and beta-pleated sheets. These newly folded patterns are stabilized by hydrogen bonds between the backbone atoms of the chain.
3. Tertiary structure refers to the overall 3D shape of the entire polypeptide chain, which results from the repeated patterns in the secondary structure. It is stabilized by various interactions between the side chains of amino acids (hydrogen bonds, ionic bonds, etc.)
4. Quaternary structure refers to the resulting shape when two or more polypeptide chains (subunits) come together to form a functional protein. Basically, many tertiary structures join together through various bonds to form one big functional protein.

Each structural level is critical because it ensures that the protein will form the right shape to interact with its environment and perform its specific function. Without the right shape at any given level, the protein may not work correctly, leading to malfunctions in other cellular processes.