The Chemistry of Life

MCAS BiologyMs Mahoney

The Chemistry of Life

• Central Concept: Chemical elements form organic molecules that interact to perform the basic functions of life.

• Essential Elements– Recognize that biological organisms are composed

primarily of very few elements. The six most common are C, H, N, O, P, and S.

Hierarchy of Life• Organism • Organ System• Organ• Tissue• Cell• Organelles• Compounds• Elements/Atoms

6 Essential Elements for LifeELEMENT SYMBOL

Carbon C

Hydrogen H

Oxygen O

Nitrogen N

Sulfur S

Phosphorus P

4 most important: H O N C if you love Life!!!

Carbon• Used in all of life’s compounds• Most Important for life• Creates connections (bonds) with many other

elements– H N O S P and C– Creates many different compounds (organic)

The Chemistry of Life

• Central Concept: Chemical elements form organic molecules that interact to perform the basic functions of life.

• Organic Compounds– Describe the basic molecular structures and

primary functions of the four major categories of organic molecules (carbohydrates, lipids, proteins, nucleic acids).

Organic Compounds

• Single parts: monomers– Mono means one

• Many parts: polymers– Poly means many

• 4 Organic Compounds– Lipids– Carbohydrates– Proteins – Nucleic Acids

Lipids

• Monomer– Hydrocarbon chain and glycerin

• Examples– Fats, oils, waxes, steroids, cell membrane

• Jobs– Store energy– Keep water in or out (waterproofing)

Carbohydrates

• Made from C H and O– Glucose C6H12O6

• Monomer– Monosaccharide

• Polymer– Polysaccharide

• Examples– Sugar (ends in “ose” like glucose)– Starch, cellulose

• Jobs– Quick Energy

Proteins• Monomer

– Amino Acid• Polymer

– Polypeptide or Protein• Examples

– Enzymes (help in chemical reactions, ends in “ase”)– Hemoglobin (carries oxygen in blood)– Insulin (tells cells they can take in sugar)

• Jobs– Performs most of the body’s functions – Fight disease, movement

Nucleic Acids• Monomer

– Nucleotide• Polymer

– Nucleic Acid• Examples

– DNA, RNA, ATP• Jobs

– Holds genetic information– Helps make proteins– Carries energy (ATP)

The Chemistry of Life

• Central Concept: Chemical elements form organic molecules that interact to perform the basic functions of life.

• Enzymes– Explain the role of enzymes as catalysts that lower

the activation energy of biochemical reactions. Identify factors, such as pH and temperature, that have an effect on enzymes.

Enzymes

• Type of protein• Ends in “ase”• Catalyst

– Speed up chemical reactions– Some reactions need energy to work and enzymes

help by lowering the amount of “activation” energy

Enzymes

• Conditions that affect when enzymes work– pH

• Enzymes in the stomach work at a lower pH than in the muscles

– Temperature• Enzymes in the body work best at 98.6°F• If it gets too cold or too hot, enzymes can not work

– Chemical reactions can not work