Ch 02 Chemical Properties Flashcards
What is an atom?
The smallest unit of matter that cannot be divided. Also smallest particle which retains properties of an element. Composed of electrons, protons, and neutrons.
What is atomic number?
The number of protons in the nucleus
What is atomic weight?
The number of protons and neutrons
What is an isotope?
The atom has a different number of neutrons. C12, C13, C14
What are the biological elements?
95% carbon, oxygen, nitrogen and hydrogen
What is the molecular weight of a molecule?
The sum of the atomic weight of all the atoms
What is radioactivity?
Unstable number of protons and neutrons
What is ionic bonding?
An atom that gains or loses electrons
What is covalent bonding?
Electron sharing H:C
What is hydrogen bonding?
H polar (unequal) bonding to N, O, F
Which type of chemical reaction releases energy?
Exothermic
What is one mole?
The molecular weight in grams
Ex. water 2H=2x1=2 1O=16 the molecular weight of water is 18
What is condensation?
Water removal AKA dehydration
What is hydrolysis?
Breaking molecular bonds using water
What are the three laws of thermodynamics?
- E cannot be created or destroyed.
- Entropy - no energy transformation is 100%
- Conservation of matter
Are exothermic or endothermic are more likely to occur?
Exothermic because they are more chaotic
What element is needed for an organic molecule?
Carbon!
Is water organic or inorganic?
Inorganic!
What are four characteristics of water?
- Polar molecule
- A good solvent
- Temperature buffering
- Surface tension
What is the formula for pH?
pH = -log10 [H-]
What do acids and bases donate and accept?
Acids donate H+; accept OH-
Bases donate OH-; accept H+
What is an isomer?
Same chemistry, different structure
What is Vitamin C?
Made from glucose
Where is starch and glycogen made?
Starch is made by plants Glycogen is made by the liver
Where is cholesterol needed?
Cell membranes
What is the difference between unsaturated and saturated molecules.
Unsaturated = more double bonds Saturated = fully saturated with hydrogen atoms
What is the characteristic of polyunsaturated molecules?
the more polyunsaturated, the lower the boiling point
What is a glycolipid?
sugar coated lipid
What is meant by amphoteric?
One side likes water, the other side does not
What is a peptide bond?
a covalent bond that holds an amino acid protein together
Why is water a polar molecule?
Because of it’s shape, one side is negatively charged, and the other side is positively charged
What is an exchange reaction?
When atoms are exchanged between two molecules AB + C -> A + BC
What is an oxidation-reduction reaction?
Transfer of electrons between to molecules
What is an enzyme?
A catalyst
What is a buffer?
A solution that resists pH change. Typically a weak acid or alkali with a salt
What is a lipid?
A fatty acid
What is the order of amino acids? KNOW THIS!
- just amino acid
- hydrogen bonds, form alpha helix and beta sheet
- remainder of molecule
- number of polypeptide chains
What results when a triglyceride is hydrolyzed?
glycerol and a fatty acid
What kind of bonds are in unsaturated and saturated lipids?
Unsaturated: double bonds
Saturated: single bonds, filled with H
What does making a lipid more polyunsaturated?
Lowers boiling poing
What does hydrogenating do?
Adds H where double bonds were
What does amphoteric mean?
A molecule that reacts as an acid or a base. Also has a hydrophillic and hydrophobic end. Usually metals are amphoteric
What are glycolipids?
Sugar coated lipids
What is the structure of ATP?
C10H16N5O13P3
Compare Purines and Pyrimidines
Purines__Pyrimidines
Adenine, guainine Cytosine, thymine, uracil
MP: 214 C MP: 22 C
Define nucleic acids and what are the two types?
DNA RNA
Nucleotides of nitrogen, purine or pyrimidine, and sugar phosphate
What is a salt?
An ionic compund that results from the neutralization of an acid and a base. Electrically neutral.
What is the definition of a carbohydrate?
Sugars, starches, or celluloses.
Release energy in animals
Why are lipids non-polar?
Their ends are not charged.
Not soluble in water.
What is the difference between D- and L- amino acids?
L amino acids are manufactured in cells
D amino acids are in bacteria
What is denaturation?
When nucleic acids lose their 2nd, 3rd, and 4th structures by application with a strong acid, base or salt
