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Define an atom
An atom is the smallest stable unit of matter
Atoms of the same elemnet that have different numbers of neutrons are called
How is it possible for two samples of hydrogen to contain the same number of atoms ,yet have different weights?
Hydrogen has 3 isotopes with different mass numbers. THe heavier sample must contain a higher proportion of one or both of the heavier isotopes
Define chemical bond and identify several types of chemical bonds.
- A chemical bond is when two atoms are chemically combined
- Examples: Ionic bonds and covalent bonds
Which kind of bond holds atoms in a water molecule together? What attracts water molecules to one another?
- polar covalent bonds
- hydrogen bonds
Both oxygen and neon are gases at room temperature. Oxygen combines readily with other elements, but neon does not. Why?
- Oxygen atoms do not have a full outer energy level, so they readily react with many other elements to attain this stable arrangement
- Neon already has a full outer energy level and thus has little tenddency to combine with other elements
The chemical shorthand used to describe chemical compounds and reactions effectively is known as
Using the rules for chemical notation, write the molecular formula for clucose, a compound composed of 6 carbon atoms, 12 hydgrogen atoms, and 6 oxygen atoms.
6C + 12H + 6O --->>> C6H12O6 GLUCOSE
Identify and describe three types of chemical reactions importan to human physiology
- Decomposition Reactions
- Exchange Reactions
- Synthesis Reactions
In cells, glueose, a six-carbon molecule, is converted into two three-carbon molecules by a reaction that releases energy. How would you classify this reaction?
- Decomposition Reaction
What is an enzyme?
enzymes promote chemical reactions by lowering the activation energy requirements
Why are enzymes needed in our cells?
THey make it possible for chemical reactions, such as the breakdown of sugars, to proceed under conditions compatible with life.
Compare organic compounds to inorganic compounds.
- Organic compounds contain Carbon
- Inorganic compounds do not contain Carbon
Explain how the chimical properties of water make life possible.
- high heat capacity
- and its ability to serve as a lubricant
Define pH, and explain how the pH scale relats to acidity and alkalinity
- pH is the negative logarithm of the hydrogen ion concentration in moles per liter.
- The pH scale runes from 0-14; 0 being acidic and 14 being alkaline
WHat is the significance of pH in physiological systems?
If the body is to maintain homeostasis and thus health, the pHof different body fluids must remain within a fairly narrow range
Define the fololowing terms; acid, base and salt
Acid: any solute that dissociates in solution and releases hydrogen ions
Base: a solute that removes hydgrogen ions from a solution and thereby acts as a proton acceptor
Salt: an ionic compound containing any cation except a hydgrogen ion, and any anion except a hydroxide ion.
How does an antacid help decrease stomach discomfort?
The antacid acts as a buffer and neutralizes excess hydrochloric acid in the stomach
A food contains organic molecules with the elements C, H and O in a ration of 1:2:1. What class of compounds do these molecules belong to and what are their major functions in the body?
- The body uses carbohydrates mainly as an energy source
- Lipids contain carbon, hydrogen and oxygen, and the carbon to hydrogen ration is near 1:2. Lipids contain much less oxygen than charbohydrates
- Fatty acids
Which lipids would you find in human plasma membranes?
- small amounts of cholesterol and glycolipids
Describe a protein
proteins are the most abundant organic components of the human body. All proteins contain carbon, hydrogen, oxygen, and nitrogen
How does boiling a protein affect its structural and functional properties?
The heat of boiling breaks bonds that maintain the protein's tertiary sturcture, quaternary sturcture, or both. A protiens function depends on its structure
Describe a nucleic acid
nucliec acids are large organic molecules composed of carbon, hydgrogen, oxygen, nitrogen, and phosphorus.
A large organic molecule made of the sugar ribose, nitrogenous bases, and phosphate groups is which kind of nucleic acid?
ATP (Adenosine TriPhosphate) is a high-energy compound used by cells
WHat molecule is produced by the phosphorylation of ADP?
Identify biochemical building blocks discussed in the chapter that are the componenets of cells.
- Nucleic acids
Define metabolic turnover
the continuous breakdown and replacement of organic materials within cells