Random questions Flashcards
Draw the formulae that describe the polymerization reaction for each of the three major types of macromolecules of life. What do these reactions have in common?
Why is the evolution of photosynthesis thought to have favored the subsequent evolution of oxidative metabolism? What are the input and output of plant metabolism?
inputs: carbon dioxide, water, light(photon)
outputs: carbohydrate(usually glucose), oxygen, heat
What is the difference between primary cell cultures and immortal cell lines?
Primary cells are cells straight from the tissue with no passages. A primary cell culture may be composed of mixtures of cell types. However, appropriate laboratory procedures can be used to select the desired cell type from the mixture.
Cell lines have at least one passage. With each subsequent subculture, the cell population becomes more homogenous as the faster growing cells predominate. Cells with desired properties can be selected for using specific growth conditions such as media.
There are several means of obtaining immortalized cell lines. Some cells, such as tumor cells, are inherently immortal. Other cells, such as many rodent cells, spontaneously immortalize. After about 12 generations, these rodent cells undergo a crisis in which most of the cells die, but the few which survive are immortalized. Otherwise normal cells can often be immortalized using foreign genes which inhibit the cell’s genes to initiate senescence. By using a virus or plasmid to transfect cells with these genes, the cells are immortalized.
Saturated vs. unsaturated fatty acids
Saturated fat is fat that consists of triglycerides containing only saturated fatty acids. Saturated fatty acids have no double bonds between the individual carbon atoms of the fatty acid chain. That is, the chain of carbon atoms is fully “saturated” with hydrogen atoms.
An unsaturated fat is a fat or fatty acid in which there is at least one double bond within the fatty acid chain. A fatty acid chain is monounsaturated if it contains one double bond, and polyunsaturated if it contains more than one double bond. Where double bonds are formed, hydrogen atoms are eliminated. Thus, a saturated fat has no double bonds, has the maximum number of hydrogens bonded to the carbons, and therefore is “saturated” with hydrogen atoms. In cellular metabolism, unsaturated fat molecules contain somewhat less energy (i.e., fewer calories) than an equivalent amount of saturated fat. The greater the degree of unsaturation in a fatty acid (i.e., the more double bonds in the fatty acid) the more vulnerable it is to lipid peroxidation (rancidity). Antioxidants can protect unsaturated fat from lipid peroxidation.
What is a mole?
Mole is a unit of measurement used in chemistry to express amounts of a chemical substance, defined as the amount of any substance that contains as many elementary entities (e.g., atoms, molecules, ions, electrons) as there are atoms in 12 grams of pure carbon-12 (12C), the isotope of carbon with relative atomic mass 12. This corresponds to the Avogadro constant, which has a value of 6.02×1023 elementary entities of the substance.
Define molar concentration:
In chemistry, the molar concentration, is defined as the amount of a constituent n_i (usually measured in moles – hence the name) divided by the volume of the mixture V
