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.
1 Viruses, on the other hand, do not have any cells. 2  Viruses are made up of a protein structure called a capsid. 3  Though this capsid contains the virus's genetic material, it lacks the features of a true cell, such as cell walls, transport proteins, cytoplasm, organelles, and so on. Viruses, on the other hand, do not have any cells. 2  Viruses are made up of a protein structure called a capsid. 3  Though this capsid contains the virus's genetic material, it lacks the features of a true cell, such as cell walls, transport proteins, cytoplasm, organelles, and so on.
Viruses lack some characteristics of living organisms. Outside of living cells, viruses are not alive. Outside of the living cells, viruses cannot move, grow, or reproduce. Viruses require living cells called host cells to be alive.Ultimately, viruses act as parasites and harm or destroy their host cells.iruses are structurally simpler than regular cells. Outside of the host cells, viruses are inactive. However, inside living cells, viruses show some of the characteristics of living things. Viruses are not made up of cells.