Biology Chapter 2: Elements and Molecules

Study Notes

Elements of Life

96% of living organisms are made up of six elements: carbon, hydrogen, oxygen, nitrogen, sulfur, and phosphorus (CHONSP)
Trace elements make up less than 0.01% of living organisms
Oxygen makes up the largest proportion of living organisms at 65%
Carbon makes up 18.5% of living organisms
The human body is primarily composed of water, followed by carbon, oxygen, hydrogen, and nitrogen

Molecules of Life

Organic molecules are made up of combinations of carbon, hydrogen, oxygen, and nitrogen
Four major types of organic molecules are carbohydrates, proteins, lipids (fats), and nucleic acids (DNA and RNA)
These molecules are created by bonding smaller molecules called monomers together to form larger molecules called polymers
The process of joining monomers to form polymers is called polymerization

Monomers vs. Polymers

A monomer is a single organic molecule.
A polymer is a chain of many monomers bonded together.
The process of building polymers from monomers is called dehydration synthesis, where water is removed and energy is used.

Dehydration Synthesis

Dehydration synthesis is a process of building larger molecules (polymers) from smaller ones (monomers) by removing water.
The process occurs by joining two monomers together, releasing a water molecule as a byproduct.
Dehydration synthesis is an endergonic reaction, meaning it requires energy, which is typically provided by ATP.
Dehydration synthesis is catalyzed by enzymes, which act as biological catalysts.
Examples of dehydration synthesis include the formation of proteins from amino acids and the formation of carbohydrates from simple sugars.

Hydrolysis

Hydrolysis is a process of breaking down polymers into smaller molecules by adding water.
The process occurs by breaking the bonds between two monomers, adding a water molecule.
Hydrolysis is an exergonic reaction, meaning it releases energy, which can be in the form of ATP.
Hydrolysis is also catalyzed by enzymes.
Examples of hydrolysis include the breakdown of starch into glucose and the breakdown of proteins into amino acids.

Why Do We Eat?

We eat to obtain the building blocks and energy necessary for growth, repair, and cellular processes.
Food provides the raw materials for building new cells and for energy production.
Energy from food is stored in bonds and released through the process of hydrolysis to produce ATP, which is the energy currency of cells.

Matter in the Human Body

Matter in the human body is made up of either inorganic or organic compounds.
Inorganic compounds are compounds that generally do not contain carbon.
Organic compounds are compounds that contain carbon.
Organic compounds include carbohydrates, proteins, lipids, and nucleic acids These are the four major classes of biomolecules.

Arrangement of Elements in Organic Compounds

Carbon atoms can bond to other atoms in chains or rings.
This allows for the creation of a vast diversity of organic molecules with various structures and functions.

Description

Explore the fundamental elements of life and the organic molecules that make up living organisms. This quiz covers the roles of elements like carbon and oxygen, the types of organic molecules, and the processes of polymerization. Test your understanding of monomers and polymers in biological contexts.