Question

Study guide Chapter 1: 1. Which are the six most common elements in nature? Which common chemical groups can be formed? How do these chemical groups participate in different interactions such as hydrogen bonding, electrostatic interactions, van der Waals interactions, hydrophobic interactions? 2. How do the chemical groups discussed above form the four main building blocks for the biomolecules (amino acids, nucleotides, simple sugars, and fatty acids)?

Answer 1

1. the six most common elements in nature are oxygen (O), carbon (C), Hydrogen (H), Nitrogen (N), Phosphorus (P)and Sulfur (S). Most of the living organisms are made of these elements.

The chemical groups these elements can form are methyl, Alcohols R-OH, carboxylic acids R-COOH, phosphates R-PO4, amines R-NH2, carbonyls RCOR', sulfhydryl R-SH. These are the key functional groups all the living matter is made of.

In these chemical groups electronegative atoms oxygen and Nitrogen are capable of behaving as hydrogen bond donors and acceptors depending the hydrogen or electron pairs they carry. Some examples of hydrogen bonding functional groups are alcohols, amines, carboxylic acids, and phosphate groups etc.

Electronegative atom nitrogen or oxygen containing functional groups carry polar bonds which result in strong electrostatic interactions with other molecules. examples are amines and carboxylic acids.

Lengthy alkyl groups and apolar molecules undergo Van der Waals and hydrophobic interactions examples are fatty acids and lipids.

2. All life is mainly composed of 4 key building blocks they are amino acids, nucleotides, carbohydrates and fatty acids.

According to one hypothesis in early life forms amino acids are made by combining ammonia, hydrogen, methane and spark.

Similarly, sugars are made by plants and organisms combining carbon di oxide and water.

It is suspected early life organisms made early forms of protein using amino acids which made nucleotides and fatty acids from the primordial molecules.