Unit 1: Chemistry of Life (copy)

What are elements?

Substances that cannot be broken down into simpler substances by chemical means.

What four elements are primarily used to build biological molecules?

Oxygen (O), carbon (C), hydrogen (H), and nitrogen (N).

What are trace elements?

Elements required by an organism only in very small quantities, such as iron (Fe), iodine (I), and copper (Cu).

What are atoms?

The unit of life and the building blocks of the physical world.

What charges do protons and electrons carry?

Protons are positively charged (+) and electrons are negatively charged (–).

What are isotopes?

Atoms that have the same number of protons but differ in the number of neutrons in the nucleus.

What is a compound?

A substance that consists of two or more elements.

What defines an ionic bond?

An ionic bond is formed when one or more electrons are transferred from one atom to another.

What is a covalent bond?

A bond formed when electrons are shared between atoms.

What are the properties of water attributed to hydrogen bonds?

Cohesion, adhesion, surface tension, high heat capacity, and expansion on freezing.

What is capillary action?

The ability of water to rise up the roots, trunks, and branches of trees due to cohesive and adhesive forces.

How does pH measure acidity or alkalinity in a solution?

pH measures the concentration of hydrogen ions; solutions with high H+ concentrations are acidic, while those with OH– are basic.

What is the role of carbon in organic molecules?

Carbon is a versatile atom that can bind with other carbons and various other elements, crucial for life.

What are polymers and monomers?

Polymers are chains of building blocks (macromolecules), while monomers are the individual building blocks of a polymer.

What are the four classes of organic compounds central to life?

Carbohydrates, proteins, lipids, and nucleic acids.

What is the ratio of carbon, hydrogen, and oxygen in carbohydrates?

Approximately 1:2:1.

What is a glycosidic linkage?

The bond formed when two monosaccharides are joined together, resulting in a disaccharide.

What do polysaccharides consist of?

Many repeated units of monosaccharides; examples include starch, cellulose, and glycogen.

What is the primary function of cellulose?

To provide structural support in the cell walls of plants.

What are amino acids?

The building blocks of proteins that contain carbon, hydrogen, oxygen, and nitrogen.

What is a peptide bond?

The bond formed between the carboxyl group of one amino acid and the amino group of another.

What structure forms when a polypeptide chain twists and folds?

A 3D structure known as a protein.

What is the basic structure of lipids?

Lipids consist of carbon, hydrogen, and oxygen atoms.

What are triglycerides?

Lipids composed of a glycerol backbone and three fatty acid chains.

What distinguishes phospholipids from other lipids?

Phospholipids have two hydrophobic fatty acid tails and one hydrophilic phosphate head.

What is the role of cholesterol in cell membranes?

It increases membrane fluidity and is important for making hormones and vitamin D.

What are nucleic acids made of?

Simple units called nucleotides containing carbon, hydrogen, oxygen, nitrogen, and phosphorus.

What are the primary functions of DNA and RNA?

DNA contains the hereditary blueprints for all life, while RNA is essential for protein synthesis.