Is urea cycle anabolic or catabolic?

The urea cycle is a catabolic process since amino acid catabolism results in waste ammonia and is then excreted as uric acid in urine in this cycle.

How do diatoms produce oxygen?

During photosynthesis, diatoms turn carbon dioxide into organic carbon and, in the process, generate oxygen. They are responsible for 40 percent of the organic carbon produced in the world’s oceans each year.

What is unique about diatoms?

A unique feature of diatom anatomy is that they are surrounded by a cell wall made of silica (hydrated silicon dioxide), called a frustule. These frustules have structural coloration due to their photonic nanostructure, prompting them to be described as “jewels of the sea” and “living opals”.

How do diatoms use silicon?

Diatoms are highly productive single‐celled algae that form an intricately patterned silica cell wall after every cell division. They take up and utilize silicic acid from seawater via silicon transporter (SIT) proteins.

What is produced in one turn of the urea cycle?

What is produced in one turn of the urea cycle? Explanation: 2 molecules of ammonia and 1 molecule of carbon dioxide are converted into 1 molecule of urea in every turn of the urea cycle. In addition, each cycle regenerates 1 molecule of ornithine for use in the next turn.

Where does urea cycle occur?

liver
The urea cycle takes place primarily in the liver and, to a lesser extent, in the kidneys.

What do diatoms produce?

Diatoms are considered the largest primary producers of oxygen on our planet. It is estimated that through photosynthesis, diatoms produce between 20\% and 40\% of the oxygen we breathe. During photosynthesis diatoms use energy from light to convert water and carbon dioxide into sugars for food.

How do diatoms produce glucose?

Diatoms are photosynthetic organisms that can convert the energy from sunlight into chemical energy in the form of ATP (adenosine triphosphate). This chemical reaction confers on diatoms the ability to produce their own nutrients (sugars), thus they have an autonomous metabolism and are called photoautotrophs.

Why do diatoms require silica?

. Plants take up silicic acid from water. Silicon in higher plants is incorporated into cell walls, making stems and leaves more rigid and strong. Among the phyto- plankton, diatoms have a particular need for silicon, because their frustules – the hard but porous cell walls – are composed almost entirely of silica.

Are diatoms heterotrophic or autotrophic?

Diatoms are unicellular, colonial, or filamentous autotrophic organisms that live in marine and freshwater habitats. Diatoms are heterokonts, but typically lack flagella, except on gametes.

Where does urea come from?

Urea production occurs in the liver and is regulated by N-acetylglutamate. Urea is then dissolved into the blood (in the reference range of 2.5 to 6.7 mmol/liter) and further transported and excreted by the kidney as a component of urine.

How do diatoms convert light energy to chemical energy?

Similar to plants, diatoms convert light energy to chemical energy by photosynthesis, although this shared autotrophy evolved independently in both lineages. Unusually for autotrophic organisms, diatoms possess a urea cycle, a feature that they share with animals, although this cycle is used to different metabolic ends in diatoms.

What happens to urea in the soil?

Various field and laboratory studies have demonstrated that urea degrades rapidly in most soils. Urea is rapidly hydrolyzed to ammonium ions through soil urease activity, which produces volatile gases, that is, ammonia and carbon dioxide.

How is urea converted to ammonia and carbon dioxide?

Urea is rapidly hydrolyzed to ammonia and carbon dioxide in environmental systems by the extracellular enzyme, urease, which originates from microorganisms and plant roots.

How do diatoms absorb silica from the cell wall?

The exact mechanism of transferring silica absorbed by the diatom to the cell wall is unknown. Much of the sequencing of diatom genes comes from the search for the mechanism of silica uptake and deposition in nano-scale patterns in the frustule.