Thursday, August 25, 2016
Class Days: August 23rd and 25th
- After the integrating center, there are several possible ‘tracks’ of response. Some reflexes fix a problem, while others just keep the effects of the problem in check
- Adaptation is a resultant physiological change that happens across a generation. It involves a change in gene frequency across a population. This concept is the base of evolutionary theory
- Acclimatization is a resultant physiological change that happens in an individual over a relatively short period of time. An example of this is your body adjusting to seasonal temperatures
• The two previous terms both stem from an environmental change, but it is important to recognize the distinction
- Acute Change is short term and sudden, like a reflex
- Chronic Change is longterm and slower onset (both adaptation and acclimatization fall into this category)
- Chemical Bonds are interactions between atoms. These are important in this class because they result in various physiological effects. They are listed in strength order.
• Covalent - electron sharing between atoms. A chemical reaction is required to make and break these bonds, which is unique to this type of bond. There are two kinds of covalent bonds:
- Polar means the electrons aren't shared equally, one atom is substantially more electronegative which means it pulls the electrons slightly closer to it and the result is a slightly positive side of the atom and a slightly negative side
If you want to learn more check out What was the purpose of thomas jefferson writing the declaration of independence?
- Nonpolar means the electrons are shared equally
• Ionic - electron transfer from one atom to another. This kind of bond comes from an attraction between opposite charges. The atom that gains the electron is the anion and becomes negatively charged, while the atom that loses an electron is the cation and becomes positively charged. This makes the substance created inherently polar
Thursday, August 25, 2016
• Hydrogen - these bonds come from the slight charges that result from a polar covalent bond. Usually these involve hydrogens attached to Oxygen, Nitrogen, or sulfur
• Van der Waals - these are week forces that are due to the masses of the nuclei - An important rule for biochemistry is LIKE DISSOLVES LIKE meaning that polar compounds usually only readily dissolve in other polar compounds (called water soluble, hydrophilic, and lipophobic), while nonpolar compounds usually only readily dissolve in other nonpolar compounds (called lipid soluble, lipophilic, hydrophobic) - Think of polarity as a continuum, not a category based system. Things have varying degrees and levels of polarity
- The ‘middle ground’ of polarity is the Amphipathic group, which includes molecules that have a polar part and a nonpolar part. Think cell membrane made of phospholipids, with a polar head and a nonpolar tail We also discuss several other topics like How does vasopressin reduce water loss?
- There are several classes of relevant molecules to this class:
• Carbohydrates - also called sugars. Have roughly equal composition of Carbon and Oxygen, with roughly twice as many hydrogens
- Glucose is the ‘perfect’ basic carb: C6H12O2 If you want to learn more check out What are the 3 objective lenses on a microscope?
- Monosaccharides are simple sugars. These include glucose, galactose, fructose - Oligosaccharides are slightly larger and typically serve as signaling molecules - Polysaccharides are the biggest and they are energy stores like glycogen (chain of glucoses) and starch (plant energy molecule) We also discuss several other topics like What are your thoughts on if the government should have a right to create and enforce policies?
- All of these forms are very important because glucose is the body’s preferred source of ATP, energy
• Lipids - fatty acids are the amphipathic building block for lipids. They incorporate a long EVEN amount of Carbons with the necessary Hydrogens and on the end there is an acidic carboxyl group. The words saturated, unsaturated, and polyunsaturated refer to hydrogen saturation of the molecule
- Triglycerides are a glycerol and three fatty acids, which store energy compactly. This is the fat molecule, and it is overall non polar since the polar oxygens are encased
Thursday, August 25, 2016
- Phospholipids are a glycerol, 2 fatty acids, and a phosphate. These form cell membranes
- Steroids are highly lipid soluble and are chemical messengers. They building block is cholesterol, so they are rings as opposed to a chain
• Proteins- built of amino acids. These are an amino group, joined with a carboxyl group, and any of the ‘R’ residual molecules. Amino acid built molecules are referred to as peptides. The distinction has to do with the size. Proteins are around at least 50 amino acids. Proteins have 3D complexity, and these levels of structure are as follows:
- Primary is the pattern of amino acids, how many and in what order - Secondary is the general group of related sequences form what regular shape. An example is the alpha helix, or spiral that hydrogen bonds form in DNA We also discuss several other topics like What were the trustees rules for georgia colonists?
- Tertiary is the secondary structure folded onto itself due to R-group interactions - Quantary/Quaternary comes when multiple polypeptides are intertwined • Proteins have many different functions for our cells
• Denaturing happens when proteins are altered in shape due to environmental change without disrupting the existing covalent bonds. Weaker bonds might be altered, which changes the secondary and tertiary structures. Temperature, ionic concentration, and pH change can denature
• Degrading happens when the primary structure is disrupted, so the covalent bonds are broken or altered from some chemical reaction that came from environmental change We also discuss several other topics like How do different attitudes about women’s rights influence politics?
Thursday, August 25, 2016
• In regard to DNA (the genetic protein), Exons are the expressed sections of our genetic material, while Introns are the sections of the code that are spliced out of the mRNA copy because they are not needed for the coding of that particular protein. Splicing allows for a single section of the same copied mRNA to code for several different proteins
• Transcriptional Control occurs when enzymes prevent or catalyze making mRNA copies of the DNA
• Translational Control occurs when enzymes prevent or catalyze protein synthesis from the existing mRNA copies
• The folding of proteins is crucial to their function. Sometimes the folding happens automatically after formation, and sometimes helper proteins have to hold parts in place. The correct environmental conditions are important for proper protein shape and function
• Enzymes have no direct effect on a reaction, they only affect speed • Concentration dictates direction and rate of reversible reactions
• Binding of a ligand is due to the shape and charge distribution that the correct protein folding allows for. The area where it attaches is called a Binding Site. Changes in the environment alters the binding site and therefore can inhibit or allow attachment of a ligand. The important characteristics of binding sites are the following:
- Affinity - measure of how readily the bond between the ligand and binding site is made and how long it lasts
- Specificity - exactness in shape and size
- Competition - how many different ligands can readily bind to the site - Saturation - how much of a particular ligand is available for the site