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.
All cells have a cell membrane and the cytoplasm (liquid medium). A nucleus is found in eukaryotic cells, along with various organelles such as ribosomes, vacuoles and mitochondria.Viruses have neither, and instead have a protein coat and a structure, usually a tail, that can penetrate a living cell.owever plant cells, in addition to the cell membrane also have the cell wall outside the cell membrane. This provides mechanical rigidity to the cell and prevents the flow of larger particles. 7 people found this useful.