The tricarboxylic acid cycle (TCA cycle) is a series of enzyme-catalyzed chemical reactions that form a key part of aerobic respiration in cells. This cycle is also called the Krebs cycle and the citric acid cycle.

Primary carbon dioxide acceptor in C4 plant is phosphoenol pyruvic acid,it contains 3 carbon atoms. in C₃ plants ribulose 1,5 bisphosphate (RUBP) is the primary CO₂ acceptor. It is a 5 carbon compound. In C₄ plants phospho enol pyruvate (PEP) is primary CO₂ acceptor.

If the breathing rate and blood flow cannot supply enough oxygen to your working muscles, the body turns to anaerobic respiration. This is the production of energy without the use of oxygen. This system works by producing lactic acid to facilitate energy production.

In biochemistry, flavin adenine dinucleotide (FAD) is a redopx-active coenzyme associated with various protiens, which is involved with several important enzymatic reactions in metabolism. A flavoprotien is a protein that contains a flavin group, this may be in the form of FAD or flavin mononucleotide(FMN).

An electron microscope uses an 'electron beam' to produce the image of the object and magnification is obtained by 'electromagnetic fields'; unlike light or optical microscopes, in which 'light waves' are used to produce the image and magnification is obtained by a system of 'optical lenses'.

'Anaphase', is the stage of mitosis after the metaphase when replicated chromosomes are split and the daughter chromatids are moved to opposite poles of the cell. Chromosomes also reach their overall maximum condensation in late anaphase, to help chromosome segregation and the re-formation of the nucleus.

 Ivanoski reported in 1892 that extracts from infected leaves were still infectious after filtration through a Chamberland filter-candle. Bacteria are retained by such filters, a new world was discovered: filterable pathogens. However, Ivanovski probably did not grasp the full meaning of his discovery. Beijerinck, in 1898, was the first to call 'virus', the incitant of the tobacco mosaic. He showed that the incitant was able to migrate in an agar gel, therefore being an infectious soluble agent, or a 'contagium vivum fluidum' and definitively not a 'contagium fixum' as would be a bacteria. Ivanovski and Beijerinck brought unequal but decisive and complementary contributions to the discovery of viruses.

Normal RBCs have a diameter of 6 - 7.5 μm. On a peripheral blood smear, normal RBCs are disc-shaped with a pale-staining central area called the central pallor. When judging red cell size on a blood smear, the classic rule of thumb is to compare them to the nucleus of a small normal lymphocyte

The net energy gain in fermentation is 2 ATP molecules/glucose molecule. In both lactic acid and alcoholic fermentation, all the NADH produced in glycolysis is consumed in fermentation, so there is no net NADH production, and no NADH to enter the ETC and form more ATP.