Chemistry and Biology Overview

Study Notes

Chemistry in Biology

The science of Biology is based on chemistry
The interaction of chemicals determines everything from birth to death
Chemistry is used daily in everyday life
- Cooking
- Cleaning
- Bathing
- Watering plants

Atoms, Molecules, Compounds

Atoms are the fundamental building blocks of all molecules and chemical compounds
Atoms interact with other atoms through chemical bonds
Chemical bonds define how chemical compounds form, break down, and reform

The Chemistry of Life

Organisms are composed mainly of:
- Oxygen
- Carbon
- Hydrogen
- Nitrogen
Humans also contain small amounts of sodium, phosphorus, sulfur, and chlorine
Molecule: When two or more atoms are chemically bonded together
- For example, H2 (hydrogen gas)

Chemical Bonds

Atoms can chemically bond in three ways:
- Ionic bonds
- Covalent bonds
- Hydrogen bonds

Organic Compounds

Contain carbon atoms
Carbon atoms have four valence electrons, which can covalently bond to up to four other atoms
This property allows carbon to create an almost endless array of carbon-based structures
Range in complexity from simple methane (CH4) to complex ring and chain structures
The reactivity of organic compounds in water makes them useful in biological systems
Organic compounds are also called macromolecules
They are made up of smaller building blocks called monomers
Monomers are joined together by condensation (dehydration) reactions and broken apart by hydrolysis

Dehydration and Hydrolysis Reactions

Condensation (dehydration) reactions: Monomers join to form a larger molecule by removing a water molecule.
Hydrolysis reaction: Larger molecules are broken down by adding a water molecule

Four Important Organic Compounds

Carbohydrates
Lipids
Proteins
Nucleic Acids

Carbohydrates

The most prevalent organic molecules in organisms
Composed of carbon, hydrogen, and oxygen in a ratio of about 1:2:1 (e.g., C6H12O6)
Serve as an energy source for the body
Many carbohydrates are saccharides (sugars)
Glucose is a key monosaccharide (simple sugar)

Classification of Carbohydrates

Monosaccharides: Single-sugar molecules (e.g., glucose, fructose, ribose, galactose)
Disaccharides: Formed by joining two monosaccharides via a glycosidic linkage (e.g., sucrose, lactose, maltose)
Oligosaccharides: Longer chains (polymers) of monosaccharides (oligo= few, and poly= many)
Polysaccharides: Complex carbohydrates, long chains (polymers) of monosaccharides (e.g., glycogen, starch, cellulose)

Polysaccharides

Glycogen: A polysaccharide that serves as energy storage in animals and stored in muscle and liver tissues
Starch and Cellulose are polysaccharides in plants
- They are long chains of glucose molecules, but arranged differently than glycogen
- Starch: Major energy storage form of glucose in plants
- Cellulose: Structural polysaccharide in plants

Glucose: Chain and Ring Structures

In solution, monosaccharides form ring structures

Description

Explore the vital relationship between chemistry and biology in this quiz. Understand how chemical interactions shape all living organisms and the essential compounds that make up life. Test your knowledge about atoms, molecules, chemical bonds, and organic compounds.