A Year of (Bio)chemical Elements

For January, it’s atomic No. 1

Quira Zeidan
Jan. 1, 2019

Following a proposal initiated by the International Union of Pure and Applied Chemistry and other global scientific organizations, the United Nations has declared 2019 the International Year of the Periodic Table of Chemical Elements, or IYPT2019.

Hydrogen High-energy electrons (from the oxidation of food, for example) passed along the electron-transport chain release energy that is used to pump H+ across the membrane. The resulting electrochemical proton gradient serves as an energy store used to drive adenosine triphosphate synthesis by the adenosine triphosphate synthase. Wikipedia

The designation commemorates the 150th anniversary of the first publication of Russian chemist Dmitri Mendeleev’s periodic table in 1869. Mendeleev’s table was not the first attempt to arrange the just over 60 chemical elements known at the time, but it was the first version to predict the existence of unidentified elements based on the periodicity of the elements’ physical and chemical properties in relation to their atomic mass.

Today’s periodic table contains at least 118 confirmed elements; of these, only about 30 are essential to living organisms. Bulk elements such as hydrogen, carbon, nitrogen and oxygen are abundant structural components of cells and tissues, whereas trace elements (iron, zinc, copper and magnesium, for example) occur in minute amounts as enzyme cofactors and stabilizing centers for protein complexes.

To celebrate IYPT2019, we are launching a yearlong series that features at least one monthly element with an important role in the molecular life sciences.

Hydrogen

For January, we selected the first element of the periodic table, hydrogen, whose atomic number 1 indicates the presence of a single proton in its nucleus. Hydrogen can occur as a single atom designated as H, as diatomic gas, or H2, in molecules such as water or natural organic compounds (such as carbohydrates, lipids and amino acids) or as negative or positive ions — H- or H+, respectively — in ionic compounds.

Living organisms use hydrogen in oxidation-reduction, or redox, reactions and electrochemical gradients to derive energy for growth and work. Microbes can uptake H2 from the environment and use it as a source of electrons in redox interconversions catalyzed by enzymes called hydrogenases. The transfer of electrons between H2 and acceptor molecules generates H+, and it’s accompanied by substantial energy changes that can be used for cellular metabolism such as synthesis of molecules, cell movement and solute transport.

Cells also use H+ to generate energy from the breakdown of foods such as sugars, fats and amino acids in a process called cellular respiration. In a cascade of metabolic reactions, nutrients like glucose are oxidized and split into smaller molecules, yielding reduced nicotinamide adenine dinucleotide, or NADH, and reduced flavin adenine dinucleotide, or FADH2 as biochemical intermediates.

Under aerobic conditions, a series of proteins that comprise the electron transport chain transfer electrons from NADH and FADH2 to cellular oxygen while pumping H+ across a membrane. This process generates a strong H+ electrochemical gradient with enough force to drive the activity of the adenosine triphosphate synthase, resulting in biochemical energy production as the gradient dissipates.

The potential energy in H+ gradients can be used to generate heat for thermogenesis in the brown fat tissue of hibernating mammals, to power flagellar motors in bacteria, to transport nutrients into cells or to generate low pH inside vacuoles. These examples highlight the ubiquitous role of a single element — hydrogen — in essential-for-life biochemical reactions across multiple kingdoms.

 

Enjoy reading ASBMB Today?

Become a member to receive the print edition monthly and the digital edition weekly.

Learn more
Quira Zeidan

Quira Zeidan is the ASBMB’s education and public outreach coordinator.

Get the latest from ASBMB Today

Enter your email address, and we’ll send you a weekly email with recent articles, interviews and more.

Latest in Science

Science highlights or most popular articles

Corals and sea anemones turn sunscreen into toxins
News

Corals and sea anemones turn sunscreen into toxins

May 14, 2022

Understanding how could help save coral reefs.

The body’s response to allergic asthma also helps protect against COVID-19
News

The body’s response to allergic asthma also helps protect against COVID-19

May 14, 2022

It all comes down to an immune system protein known as interleukin-13

Stem cell–derived model offers insights on gene activity and addiction
News

Stem cell–derived model offers insights on gene activity and addiction

May 13, 2022

“Our work here is the first experimental study to demonstrate gene desensitization in human neuronal cells, specifically in response to dopamine,” first author Ryan Tam said.

Changes in cholesterol production lead to tragic octopus death spiral
News

Changes in cholesterol production lead to tragic octopus death spiral

May 12, 2022

New research finds remarkable similarities in steroid hormone biology across cephalopods, mice and humans that can have dire consequences when disrupted.

From the journals: JLR
Journal News

From the journals: JLR

May 12, 2022

How our bodies adapt to nutrient starvation in cancer. How mimetic peptide treats systemic inflammation. Read about these recent JLR studies.

The gift of sight
Health Observance

The gift of sight

May 12, 2022

The human eye is an evolutionary phenomenon, one of aesthetic beauty and profound function. May is Healthy Vision Month.