W1-lecture 2: Structure and function Flashcards
What are the properties of all cells?
Metabolism Growth Evolution
What are the properties of some cells?
Differentiation Communication Genetic exchange Motility
T or F : There is an advantage of being small because your surface-to-volume ratio is higher.
T
What are the building units of the cytoplasmic membrane
constructed from either phosphoglycerol diethers, which have C20 side chains (called a phytanyl group) or diphosphoglycerol tetraethers (C40 side chains, called a biphytanyl group)
What stabilize the membrane in : animal cells, fungi and plant cells (and protozoans)
Animal : Cholesterol Fungi : Ergosterol Plan cells and some protozoans: Stigmaterol
T or F : In bacteria and archaea, sterols are almost always absent.
T, the membrane is stabilize by hopanoids in bacteria
What stabilize the membrane in bacteria
hopanoids (sterol life structure)
in procryotes, the ribosomes subunits are : ___S and ___S
30 + 50 = 70S
in eucaryotes, the ribosomes subunits are : ___S and ___S
40 + 60 = 80S
What is the difference between a cell wall and a membrane?
The main difference between cell wall and cell membrane is, cell membrane is present in all cells but cell wall is only present in plants, bacteria, fungi and algae. It is not present in the Protozoa and animal cell. Cell wall covers the cell membrane, which is a partially permeable membrane.
What are the differences between the layer of the archea and the bacteria?
1- the hydrophobic lipid in archaea is not a fatty acid it is repeated units of isoprene 2- the link between the hydrophobic part anf the glycerol is an ether in the case of archaea instead of an ester 3- Can form a bi-layer or a mono-layer in the case of archaea
What is the name of the major phospholipid found in bacteria?
Phophatidylethanolamine
What type of linkage link the phosphoglycerol and the hydrophobic portion (phyntanyl)
ether linkage as opposed to a ester linkage in the case of bacteria and eukaryotes
What are the three functions of the membrane?
1- Permeability barrier 2- Protein anchor 3- Energy conservation (for archae and bacteria)
What is composed the lipid portion in the bi-layer of archaea?
Isoprene units (5 carbons)
How many carbons is there in a phyntanyl group?
20Carbons
What are the three types of phosphoglycerol that you can find in the membrane of archaea?
1- Phosphoglycerol diether 2-Diglycerol tetraethers 3-Crenarchaeol
T or F : protozoan’s cell wall is made of cellulose.
F, the protozoans don’t have a cell wall.