Biology Chap 2 Flashcards
hydrophilic
water loving, polar good solvents
hydrophobic
water fearing, nonpolar arrange themselves in a manner to minimize their contact with H20
hydrophobic effect
polar molecules like water exclude nonpolar ones, drive such processes like the formation of all membranes, and the folding of proteins
organic molecules
carbon containing molecules, carbon is essential to life, it has the ability to combine with many other elements to form a wide variety of molecules
Proteins
provide structural and act as catalyst that facilitate chemical rx
Nucleic Acid
encode and transmit genetic information
Carbohydrates
provide a source of energy and make up the cell wall in bacteria, plants, and algae
Lipids
make up cell membranes, store energy, and act as signaling molecules
Polymers
complex molecules made up of repeated simpler units connected by covalent bonds
Amino acids
nonessential amino acids synthesized in body
essential amino acids must be obtained
Nucleotides
organic molecules that serve as monomers, of DNA, RNA. Building blocks of nucleic acids. Nitrogenous base, 5 carbon sugar, at least 1 phosphate group
enyzmes
proteins that function as catalyst which accelerate the rates of chemical rx
alpha carbon
central carbon atom
carboxyl group
COOH: red
Amino group
NH2: blue
Ribose
sugar in RNA, has a hydroxyl group on the 2nd carbon
deoxyribose
sugar in DNA, has a hydrogen on the 2nd carbon
Pyrimidine Base
T, C, U (thymine, cytosine, uracil)
Purine Base
A, G (adenine, guanine)
DNA bases
A, T, G, C
RNA bases
A, U, G, C
phosodiester bond
forms when a phosphate group in one nucleotide is covalently joined to the sugar unit in another nucleotide
complementary
two bases,
A–T
G–C
Carbohydrates
distinctive molecules composed of C,H,O atoms usually in the ratio 1:2:1. Provide a principle source of energy for metabolism
Saccharides
simplest carbohydrates, cylic molecules containing 5 or 6 carbon atoms
Aldoses
monosaccharides with an aldehyde group
Ketoses
monosaccharides with a ketose group
glycosidic bonds
the covalent bonds that attach monosaccharides
Lipids
hydrophobic, because they share a property and not a structure, they are chemically diverse
Triacylglycerol
a lipid used for energy storage, major component of animal fat and vegetable oil.
Made up of 3 fatty acids joined to glycerol
Saturated
fatty acids that DO NOT contain double bonds—Said to be saturated because the carbon atoms contain max hydrogen atoms (straight chains)
unsaturated
fatty acids that contain carbon-carbon double bonds, have a kink at each double bond
steroids
2nd type of lipid, core composed of 20 carbon atoms, bonded to form 4 fused rings, hydrophobic
Phospholipids
3rd type of lipid, major component of the cell membrane,. Phospholipids are made up of glycerol attached to two fatty acids and a 3rd molecule containing a phosphate group.. both hydrophilic, and hydrophobic
bilayer
a two layered structure with the hydrophilic heads pointing outward toward the aqueous environment and the hydrophovic tails oriented inward, away from the water
What percentage of carbon’s orbitals are spherical in conformation?
40%
Which one of the following contributes to the measurement referred to as atomic mass?
protons and neutrons
If hydrogen bonds between water molecules were weaker than they are today, how would this affect plant height?
As hydrogen bonds are responsible for the movement of water through plant vasculature, plants would be shorter.
A woman’s doctor tells her to gargle with salt water. She stirs a tablespoon of salt into a cup of warm water, and watches it dissolve. Why does the salt dissolve in water?
The positive hydrogen atoms in water molecules are attracted to chlorine ions, and the negative oxygen atoms in water molecules are attracted to sodium ions.
When two atoms form a covalent bond, they share electrons from all of their orbitals. All of their orbitals, in turn, combine to form a single molecular orbital
false
Where would the highest-energy electron be found in an atom of hydrogen?
in the spherical orbital closest to the nucleus
Which of the following statements is true regarding atomic mass?
The atomic mass can be used to differentiate between different isotopes of the same element.
Water is neither hydrophilic nor hydrophobic, as these terms only define the interaction of other molecules with water molecules
false
A polar bond is due to:
uneven sharing of electrons in a covalent bond.
