Biology - Chemistry of Life - Levels, Macromolecules, and Enzymes Review

Levels of biological organization from simplest to most complex

Atoms → Molecules → Cells → Tissues → Organs → Organ Systems → Organisms

Six most important elements in living organisms

Carbon, Hydrogen, Oxygen, Nitrogen, Phosphorus, Sulfur

Element found in all organic living organisms

Carbon

Molecular formula of water

$$H_2O$$

Polarity

The distribution of electrical charge over bonded atoms, creating slight positive and negative regions.

Hydrogen bond

A weak attraction between a hydrogen atom covalently bonded to an electronegative atom and another electronegative atom.

Universal solvent

The property of water that enables it to dissolve more substances than any other liquid.

Cohesion vs. adhesion

Cohesion is the attraction between molecules of the same substance, whereas adhesion is the attraction between molecules of different substances.

High specific heat capacity

The property of water that allows it to absorb significant heat energy before experiencing a temperature change.

Four major biological macromolecules

Carbohydrates, Lipids, Proteins, Nucleic Acids

Monomers of the four biological macromolecules

Carbohydrates: monosaccharides; Lipids: fatty acids and glycerol; Proteins: amino acids; Nucleic Acids: nucleotides

Importance of protein shape

Determines its biological function and how it interacts with other molecules.

Food sources of carbohydrates

Grains, fruits, vegetables, and legumes

Food sources of lipids

Oils, butter, nuts, and avocados

Food sources of proteins

Meat, dairy products, beans, and nuts

Polysaccharide

A carbohydrate formed from long chains of monosaccharides, such as starch and glycogen.

Functions of carbohydrates

Providing energy, serving as structural components, and storing energy

Functions of lipids

Storing energy, providing insulation, and forming cell membranes

Functions of proteins

Catalyzing biochemical reactions, providing structural support, and transporting molecules

Functions of nucleic acids

Storing and transmitting genetic information

Saturated vs. unsaturated lipids

Saturated lipids have no carbon-carbon double bonds and are solid at room temperature; unsaturated lipids contain one or more double bonds and are liquid at room temperature.

Enzyme

A biological catalyst that accelerates chemical reactions in living organisms.

Denatured enzyme

An enzyme whose structure has been altered, rendering it inactive and unable to catalyze reactions.

Reusability of enzymes

Enzymes remain unchanged after catalyzing a reaction and can be reused repeatedly unless denatured.