NIH NCBI

Science Facts Written by NIH NCBI

Biology

Proteins In General

Proteins form our bodies and help direct its many systems. Proteins are fundamental components of all living cells. They exhibit an enormous amount of chemical and structural diversity, enabling them ... Continue reading

Biology

Prokaryotic Organisms

It appears that life arose on earth about 4 billion years ago. The simplest of cells, and the first types of cells to evolve, were prokaryotic cells--organisms that lack a nuclear membrane, the ... Continue reading

This figure illustrates a typical bacterium (prokaryote) and demonstrates how bacterial DNA is housed in a structure called the nucleoid (very light blue), as well as other structures normally found in a prokaryotic cell, including the cell membrane (black), the cell wall (intermediate blue), the capsule (orange), ribosomes (dark blue), and a flagellum (also black).

Biology

Eukaryotic Organisms

Eukaryotes include fungi, animals, and plants as well as some unicellular organisms. Eukaryotic cells are about 10 times the size of a prokaryote and can be as much as 1000 times greater in volume. ... Continue reading

This figure illustrates a typical human cell (eukaryote) and highlights the internal structures of eukaryotic cells, including the nucleus (light blue), the nucleolus (intermediate blue), mitochondria (orange), and ribosomes (dark blue).

Science

Classifying Organisms

Have you ever noticed that when you see an insect or a bird, there is real satisfaction in giving it a name, and an uncomfortable uncertainty when you can't? Along these same lines, consider the ... Continue reading

Biology

Proteins Function Through Their Conformation

To produce proteins, cellular structures called ribosomes join together long chains of subunits. A set of 20 different subunits, called amino acids, can be arranged in any order to form a polypeptide ... Continue reading

Engineering

Bioinformatics

Bioinformatics is the field of science in which biology, computer science, and information technology merge to form a single discipline. The ultimate goal of the field is to enable the discovery of ... Continue reading

Biology

Microarrays: Chipping Away At The Mysteries Of Science And Medicine

With only a few exceptions, every cell of the body contains a full set of chromosomes and identical genes. Only a fraction of these genes are turned on, however, and it is the subset that is ... Continue reading

Biology

Genome Mapping: A Guide To The Genetic Highway We Call The Human Genome

Imagine you're in a car driving down the highway to visit an old friend who has just moved to Los Angeles. Your favorite tunes are playing on the radio, and you haven't a care in the world. You stop ... Continue reading