Objectives By the end of this lesson you should be able to: Describe the macrostructure of the chromosome Identify the phases in interphase Identify the phases in mitosis Describe the mechanism of cell division Identify the phase of mitosis illustrated on a microscope slide Explain how cytokinesis in plants and animal cell is different […]
One would be reasonable to think that with so much information stored on the DNA that errors must happen pretty often. However, the DNA is usually very accurate and almost error-free. When errors occur; even small ones, disease may be the result. Here is an outline of what to expect. Autosomal Dominant Disorders Disorders of […]
Illustration In order to communicate, human beings have developed verbal language. However, we recognized that it was easier and more accurate to pass on important information by writing things down. So, we developed written language and created books to write them in. In order to organize and store our books we invented bookcases. Further on, […]
Fluid Mosaic Model Cells are enclosed by a double-layered fluid membrane called the lipid bilayer. It consists of a mosaic of components which include proteins, glycoproteins, glycolipids, phospholipids, saturated and unsaturated fatty acids, and cholesterol. The phospholipid heads are polar, allowing them to orient themselves towards the watery cytoplasm and extracellular space. The hydrophobic tails […]
Polarity An important concept that you will encounter in biochemistry is the hydrophobic and hydrophilic nature of different compounds. A compound is hydrophobic if it cannot dissolve in water, and hydrophilic if it can dissolve in water. You may already know from experience that fats and oils are hydrophobic, which makes them float on top […]
Proteins can be separated based on their isoelectric point and molecular weight using electrophoresis. This allows us to observe and compare structural and functional differences in proteins, and enables further analysis of specific proteins we may want to study. Separation by Isoelectric Point Separation by isoelectric point is called isoelectric focusing. In this technique, samples […]
Regulation of energy metabolism can occur at the gene level, where enzymes needed for energy metabolic pathways are either transcribed, or their transcription inhibited. A well-studied example is the Lac Operon which can be seen in E. coli bacteria. The Lac Operon is characterized by an operator which is essentially an on/off switch that controls […]
Three sequences of nucleotides called a codon on the mRNA code for amino acids. There are 64 codons. Sixty-one of them code for amino acids including AUG which is a start codon corresponding to methionine. Three codons are referred to as STOP codons. Stop codons terminate translation of mRNA. The stop codons are UGA, UAA, […]
The DNA contains the code for making all proteins. In order for proteins to be synthesized, the code on the DNA for making the protein of interest must be transcribed. Imagine trying to make a cake (the protein) that you have never made before. Consider that the book with the recipe is in a rare […]
