Biochemistry Chapter 1

Study Notes

Biochemistry is the study of the chemical substances and processes that occur in plants, animals, and microorganisms.
Living organisms are made up of biological molecules, which can be grouped into four major classes: carbohydrates, proteins, lipids, and nucleic acids.
Cells are the structural and functional units of all living organisms.
The cell membrane is a barrier to the free passage of inorganic ions and most other charged or polar compounds.
Transport proteins in the plasma membrane allow the passage of certain ions and molecules.
Receptor proteins transmit signals into the cell, and membrane enzymes participate in some reaction pathways.
The internal volume enclosed by the plasma membrane is composed of an aqueous solution, the cytosol, and a variety of suspended particles with specific functions.
Most cells are microscopic, invisible to the unaided eye.
Animal and plant cells are typically 5 to 100 mm in diameter, and many unicellular microorganisms are only 1 to 2 mm long.
Eukaryotic cells contain a variety of membrane-bounded organelles and large particles.
All living organisms fall into one of three large groups (domains) that define three branches of the evolutionary tree.

Biomolecules are compounds of carbon with a variety of functional groups.
Cells contain a universal set of small molecules.
Elements essential to animal life and health include bulk elements (such as carbon, oxygen, and nitrogen) and trace elements (such as iron, copper, and zinc).
Macromolecules are the major constituents of cells.
The ABCs of biochemistry include amino acids, nitrogenous bases, sugars, and phosphate ions.

Living cells and organisms must perform work to stay alive and to reproduce themselves.
The synthetic reactions that occur within cells require the input of energy.
Living organisms exist in a dynamic steady state, never at equilibrium with their surroundings.
Maintaining this steady state requires the constant investment of energy.
Organisms transform energy and matter from their surroundings.
The flow of electrons provides energy for organisms.
Creating and maintaining order requires work and energy.
Energy coupling links reactions in biology.

The structure of DNA allows for its replication and repair with near-perfect fidelity.
The linear sequence in DNA encodes proteins with three-dimensional structures.
The central issue in bioenergetics is the means by which energy from fuel metabolism or light capture is coupled to a cell's energy-requiring reactions.