Protein Synthesis is broken up into two stages: Transcription and Translation. Transcription happens when the DNA is unwinded and unzipped by the enzyme Helicase. Helicase travels up the middle of the DNA and splits the hydrogen bonds that hold the bases together. Next what happens is called complimentary base pairing. This is when one strand of DNA is paired up with its complimentary bases. Once that is done, a new sugar phosphate backbone is created. Finally the DNA will zip itself back up and a new mRNA strand is formed. The next step is Translation. This is when a ribosome attaches to the mRNA strand. The appropriate molecule of tRNA attaches and carries the activated amino acid to the ribosome. Anticodon bases pair with the codons in order to bring the specific amino acid to the correct place. The process repeats itself until the entire message is read and all the amino acids are brought in sequence, forming a polypeptide chain.
mRNA is coded by obtaining the codons for DNA. This is by taking the opposite bases from the sequence of DNA it is being coded by. The Thymine from the DNA is replaced by Uracil in the mRNA sequence. Using the mRNA sequence found, we can then figure out which amino acid goes where.
Mutagens such as X-Rays, Gamma Rays, Ultraviolet Rays, Chemicals and Viruses can all effect protein synthesis in a significant way. They can cause deletion and addition as well as substitution which all negatively effect us. Addition will add an extra base and screw up all of the amino acids after the addition has taken place. The same kind of situation will happen with deletion. After one base is taken out, all of the other amino acids will be incorrect. Substitution is not quite as serious as it will only mess up the one amino acid for the base it replaced. Mutations like these can cause Autism, Downs Syndrome, and other mental illnesses.
Monday, November 18, 2013
Biological Molecules
Dehydration synthesis is the process of monomers being joined together. These chains of monomers are called polymers. Hydrolysis is the breaking of these polymers into units. This is done by adding water to polymer. The monomers are the building blocks of the cell. The monomer of sugars has a polymer of Polysaccharides, the monomers Fatty Acids have a polymer of Fats/Lipids/Membranes, the monomer of Amino Acids have a polymer of proteins, and the monomer of Nucleotides have a polymer of Nucleic Acids.
The function of a carbohydrate is to create energy. When the bonds between the carbon atoms break, the energy release is then used by the cell. A carbohydrate can be three different things. A monosaccharide, a disaccharide, or a polysaccharide. A monosaccharide is a single sugar. A disaccharide is when two sugars are bonded together via dehydration synthesis. A polysaccharide is when many different sugars bond together. Four types of polysaccharides exist: Starch, Glycogen, Cellulose, and chitin.
Lipids are large molecules that are considered to be insoluable. One type of lipid is neutral fats (aka) Triglycerdies. Triglycerides are made up of three fatty acids bonded together by one glycerol. There are two types of Triglycerides: Saturated, and unsaturated fats. Saturated fats are Triglycerides with no double bonds in the carbon chains of fatty acids. These are the unhealthy fats you always hear about. They mostly come from animals, and are solid at room temperature. Some examples of saturated fats are lard, cheese, and other animal fats. Unsaturated fats are a different story. They do have one or more double bonds between the carbons. These fats usually come from plants and are liquid at room temperature. Some examples of unsaturated fats are olive oil, corn oil, and palm oil.
Phospholipids are created when the third fatty acid group of a Triglyceride is replaced by an inorganic phosphate group. Phospholipids make up the two layered cell membrane of all cells. Steroids are made up of a four carbon ring molecules fused together. Steroids can be used for things such as sex hormones.
The main functions of Lipids are long term storage of energy, insulation and protection, makes some hormones, and is the structure of the cell membrane. If we did not have Lipids, we would have no cells.
Proteins are what makes up approximately 40% of the average human body. They are made up of three parts: The amino group, carboxyl group, and the R group. There are four different levels of protein structure: Primary, Secondary, Tertiary, and Quaternary. In Primary level the order of amino acids are joined by polypeptide bonds. In the Secondary level the carboxyl group and the amino group attract and form a hydrogen bond. This means that the chain will twist into an alpha helix or a beta pleated sheet. In the Tertiary level the protein will twist into a very specific 3D shape. The shape of the protein will dictate what its role will be.
DNA is what makes you the way you are. It holds all of your genetic information. DNA has four nitrogen bases that are split into two categories. Purines have two rings, are found in both DNA and RNA, and are what Adenine and Guanine are considered to be. The trick for remembering this is "It's Got 2 Be GAP". Pyrimidines have only one ring and are what Cytosin, Thymine and in some cases Uracil when it is present.
DNA and RNA are structured very differently. RNA has Ribose instead of Deoxyribose, it has no Thymines and uses Uracil instead, and it is only single strands so there is no helix formed. RNA's sole purpose is to assist DNA.
ATP has the same structure as a nucleotide except for the fact that it has three phosphate groups instead of one. This is why it is considered a nucleic acid. ATP is known as the energy source for the body. Why is this? Because it takes a large amount of energy to put two phosphate molecules together and when the bond is broken, much of that energy is released.
The function of a carbohydrate is to create energy. When the bonds between the carbon atoms break, the energy release is then used by the cell. A carbohydrate can be three different things. A monosaccharide, a disaccharide, or a polysaccharide. A monosaccharide is a single sugar. A disaccharide is when two sugars are bonded together via dehydration synthesis. A polysaccharide is when many different sugars bond together. Four types of polysaccharides exist: Starch, Glycogen, Cellulose, and chitin.
Lipids are large molecules that are considered to be insoluable. One type of lipid is neutral fats (aka) Triglycerdies. Triglycerides are made up of three fatty acids bonded together by one glycerol. There are two types of Triglycerides: Saturated, and unsaturated fats. Saturated fats are Triglycerides with no double bonds in the carbon chains of fatty acids. These are the unhealthy fats you always hear about. They mostly come from animals, and are solid at room temperature. Some examples of saturated fats are lard, cheese, and other animal fats. Unsaturated fats are a different story. They do have one or more double bonds between the carbons. These fats usually come from plants and are liquid at room temperature. Some examples of unsaturated fats are olive oil, corn oil, and palm oil.
Phospholipids are created when the third fatty acid group of a Triglyceride is replaced by an inorganic phosphate group. Phospholipids make up the two layered cell membrane of all cells. Steroids are made up of a four carbon ring molecules fused together. Steroids can be used for things such as sex hormones.
The main functions of Lipids are long term storage of energy, insulation and protection, makes some hormones, and is the structure of the cell membrane. If we did not have Lipids, we would have no cells.
Proteins are what makes up approximately 40% of the average human body. They are made up of three parts: The amino group, carboxyl group, and the R group. There are four different levels of protein structure: Primary, Secondary, Tertiary, and Quaternary. In Primary level the order of amino acids are joined by polypeptide bonds. In the Secondary level the carboxyl group and the amino group attract and form a hydrogen bond. This means that the chain will twist into an alpha helix or a beta pleated sheet. In the Tertiary level the protein will twist into a very specific 3D shape. The shape of the protein will dictate what its role will be.
DNA is what makes you the way you are. It holds all of your genetic information. DNA has four nitrogen bases that are split into two categories. Purines have two rings, are found in both DNA and RNA, and are what Adenine and Guanine are considered to be. The trick for remembering this is "It's Got 2 Be GAP". Pyrimidines have only one ring and are what Cytosin, Thymine and in some cases Uracil when it is present.
DNA and RNA are structured very differently. RNA has Ribose instead of Deoxyribose, it has no Thymines and uses Uracil instead, and it is only single strands so there is no helix formed. RNA's sole purpose is to assist DNA.
ATP has the same structure as a nucleotide except for the fact that it has three phosphate groups instead of one. This is why it is considered a nucleic acid. ATP is known as the energy source for the body. Why is this? Because it takes a large amount of energy to put two phosphate molecules together and when the bond is broken, much of that energy is released.
Wednesday, November 6, 2013
DNA Replication
DNA Replication occurs when a cell needs to make a copy of itself to produce more of a certain protein. When the body runs low on any one type of protein, the DNA that codes for that protein will replicate itself in order to rapidly produce more of that single protein until it is no longer needed. This is done in three basic steps. First of all, the DNA will unwind itself and proceed to unzip itself. This occurs with the help of the enzyme Helicase. Helicase will move along the nitrogen bases, slicing the Hydrogen bonds that hold them together apart. Next, complementary base pairing comes into play. This happens when the enzyme DNA Polymerase moves along each single strand of DNA, forming a new backbone for each strand of DNA. Finally, the completely new sets of DNA will wind back up and become a double helix.
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