barm - a commercial leavening agent containing yeast cells; used to raise the dough in making bread and for fermenting beer or whiskey. yeast. yeast cake - small cake of compressed moist yeast. brewer's yeast - yeast used in fermenting beer. leaven, leavening - a substance used to produce fermentation in dough or a liquid. mother - a stringy slimy substance consisting of yeast cells and bacteria; forms during fermentation and is added to cider or wine to produce vinegar.
No. Being that viruses are not a living organism, they are neither contain cells, nor are they a cell themselves. Viruses are merely few macromolecules (such as nucleic acid and protein) which combines to form a pathogenic particle.dit: a cell wall-as the name implies-is a part of a cell. Viruses are not cells. â¦ Cells are living, viruses are not.
1 Most viruses infect specific host cells ie are host specific. 2  Host specificity is due to: 3  specific attachment sites on the host cells called receptors. 4  Receptor sites for bacteriophage are found in bacterial cell walls or fimbrae or flagella.5  Animal cell membranes contain receptors for animal viruses. 20nm to 14000nm in size. 2  Most are smaller than bacteria (eg Adeno virus). 3  Vaccinia virus is the same size as the small bacteria like Mycoplasma, Rickettsia & Chlamydia. 4  Contain either DNA or RNA (never both) surrounded by a protein coat (capsid) and sometimes covered by an envelope.