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Chemistry
Question | Answer |
---|---|
Why is chemistry important for physiology? | -Calcium participates in muscle contraction -Calcium, sodium and potassium are needed for nerve impulse transmission |
ATP | Adenosine Triphosphate: the body's most important energy-transfer molecule. Known as the "little battery"it briefly stores energy, and then releases it within seconds for physiological work. |
Write out the hydrolysis of ATP & results | ATP --> ADP + Pi + Energy |
How does ATP release energy? | specific enzymes are specialized to hydrolyze the third high-energy phosphate bond, releasing energy |
draw out the ATP reaction. | show the x, y, and p chains. x=adenine y=ribose |
What kind of molecule is ATP and what is it composed of? | It is a nucleotide, which must have a nitrogenous base (adenine), a 5 carbon sugar (ribose) and one or more phosphate groups. |
Atom | Too small to be seen. At the center is the nucleus, composed of protons (p+) and neutrons (n0). Protons have a single positive charge and neutrons have no charge. Around the nucleus are one or more concentric clouds of electrons (e-), tiny particles with |
Valence Shell | The last shell with electrons in it. |
How do atoms achieve stability? | Atoms tend to empty or fill their outermost valence shell. They tend to bond with other atoms that will allow them to do this. When atoms combine or break apart from eachother, then some kind of chemical rxn is occurring. |
"Inert" | things are inert if their valence shell is full |
Draw a valence shell? | |
Chemical Bonds | Produced by one atom either giving or taking or sharing electrons. These bonds that would form = potential energy (energy that is stored) |
Ionic Bond | One or more valence electrons from one atom are completely transferred to a second atom. And so, ionic bonds hold oppositely charged ions together. |
How strong are ionic bonds? Give an example of ionic bond | weaker bond. EX: sodium and chloride are attracted to eachother and form ionic bond = sodium chloride i.e. table salt. (draw this out) |
Covalent Bond | Form by the sharing of electrons. Two electrons, one donated by each at atom, swarm around both nuclei in a dumbell-shaped cloud. It is the more common bond in the body. |
Nonpolar Covalent | electrons are shared equally. They spend approximately equal time around each nucleus. |
How strong is the Nonpolar Covalent? Give an example | Strongest of all chemical bonds Nonpolar covalent, especially between carbon atoms, create the stable framework of the large molecules that make up most of the structural components of the human body |
Polar Covalent | Electrons are shared unequally. One atom attracts electrons more strongly. |
When Oxygen bonds with Hydrogen... | Oxygen has a strong tendency to pull electrons towards itself when bonded to a different atom. Thus electrons are more attracted to the oxygen nucleus and orbit around it more than they do the hydrogen. This makes the oxygen region of the molecule slight- |
Draw a polar covalent bond in a water molecule | just draw O- and two H+ with solid covalent lines between |
Why is the polar covalent bond of water important? | Because it allows it to dissolve many molecules. |
What happens when salt is dropped in a beaker? draw a picture | the ionic bonds between Sodium and Chloride are overpowered by the attraction of each ion to water molecules. The sodium ion is pulled away by the negatively charged oxygen poles and the chloride ion is pulled away by the positively charged hydrogen poles |
Hydrogen Bond | weak attraction between a slightly positive hydrogen atom in one molecule and a slightly negative oxygen or nitrogen atom in another. It determines the 3D shape of large molecules. EX: proteins, nucleic acids, etc. |
Draw a hydrogen bond between water molecules | draw water molecules with solid covalent bond then a dotted line between the O- of one molecule and H+ of a different molecule |
surface tension | when hydrogen bonding occurs between water molecules at the water's surface. |
Hydrogen bonds in proteins | Hydrogen bonds are very weak, but because we have so many that can form, it creates a very strong, firm structure. |
Primary structure | chains of amino acids linked by peptide bonds |
Secondary Structure | as amino acid chains curl up, hydrogen bonds form between molecules, which causes the chain to helix into a springlike shape (alpha helix) or to pleat into a ribbonlike shape (beta pleat) |
Tertiary structure | Further bending and folding of proteins into various globular and fibrous shapes |
Quaternary structure | Number of tertiary globs stuck together i.e. hemoglobin |
Metabolism | refers to all chemical reactions occurring in an organism |
Anabolism | building up reaction; synthesis (requires energy) A + B --> AB |
Catabolism | breaking down reaction; decomposition AB --> A + B |
Hydrolysis | Decomposition reactions needing water, very important in the breakdown of complex molecules in the body (as in digestion) |
Why are you thirsty after eating? | you need water to break down food i.e. hydrolysis reactions |
Draw Hydrolysis | A-B-C-D-E + H20 --> A-B-C-H + HO-D-E |
Dehydration Synthesis | opposite of hydrolysis, removing water to join chemical molecules together |
Example of dehydration synthesis? | glucose + fructose --> H2O + Sucrose |
pH Scale | pH = "Power of the hydrogen ion" the lower the pH, the more hydrogen ions (H+) the solution has. |
pH of stomach acid? | 1-2 |
pH of vaginal fluid? | 3.5-4.5 |
pH of saliva? | 6.35-6.85 |
pH of semen? | 7.2-7.6 |
pH of blood? | 7.35-7.45 |
an ionic bond is formed when... | an anion meets a cation |
the weaker and more temporary of chemical bonds are: | hydrogen bonds |
a substance capable of dissolving freely in water is | hydrophilic |
When an atom gives up an electron and acquires a positive charge, it is called a/n_____ | cation |
when an atom gains an electron and acquires a negative charge, it is called a/n____ | anion |
All synthesis reactions in the body form a division of metabolism called ____ | anabolism |
all decomposition reactions in the body form a division of metabolism called | catabolism |
a chemical reaction that joins two organic molecules into a larger one and produces water as a by-product is called ______ | dehydration synthesis |