Chapter 2 Flashcards
Water is polar or nonpolar?
polar
Ion and polar molecules are insoluble or soluble in water?
soluble. (they are hydrophillic) and water is polar so remember, like dissolves like
Do nonpolar molecules interact with water?
no they do not. they are poorly soluble because water is polar and nonpolar molecules are not easily dissolve/interact with water. Also nonpolar molecules are hydrophobic
What are some inorganic ions
Na^+, K^+, Mg^+2, Ca^+2, HPO4^2-,Cl^-,HCO3^- (ions)
What are the four classes of molecules?
carbohydrates, lipids, proteins, nucleic acids
what is a glycosidic bond?
this bond allows monosaccharides to be joined together by dehydration reactions (loss of water) and linkage of sugars
name two common polysaccharides that are composed entirely of glucose and molecules in alpha configuration
glycogen=storage of glucose in animal cells
starch= storage in plant cells
glycogen and amylopectin also contain alpha(1-6) bonds and they serve as____________
branch points
cellulose is the main structural component of what?
plant cell walls
what is cellulose composed of and in what configuration?
glucose molecules, B configuration
why does cellulose have B(1-4)linkages?
This linkage allows the chains to pack more tightly. This allows the cellulose to form long extended chains that pack side by side to form fibers of great mechanical strength
What are the 3 main rules of lipids?
- energy storage
- major component of cell membranes
- important in cell signaling as steroid hormones and messenger molecules
define fatty acid
are long hydrocarbon chains (16-18 carbons) with a carboxyl group (COO-) at one end
define unsaturated fatty acids
have one or more double bonds. therefore it can not bond to as many hydrogens.
define saturated fatty acids
HAVE NO DOUBLE BONDS.
the hydrocarbon chain of a fatty acid is? hydrophobic or hydrophillic?
hydrophobic
name a saturated fatty acid
palmitate or stearate
name a unsaturated fatty acid
oleate
what are fatty acids stored as?
triacylglycerols
what is a triacylglycerol?
it is three fatty acids linked to a glycerol molecule
are triacylglycerol insoluble or soluble in water?
they are insoluble in water. this is why they can accumulate as fat droplets in the cytoplasm
why are fats more efficient energy storage than carbohydrates?
fats yield more than twice as much energy per weight of the material broken down
what is the principle component of the cell membranes?
phospholipids
what are phospholipids composed of?
2 fatty acids, joined to a polar head
When talking about the phospholipid.
The Hydrophobic tails are?
The Hydrophillic head is?
hydrophobic tails=hydrocarbon chains
hydrophillic head: phosphate group and polar attachment
What do you call a molecule that is part water-soluble and part water insoluble? give a example of such a molecule.
amphipathic molecules….
phospholipids are an example
glycerol phopholipids are composed of?
2 fatty acids bound to glycerol. bound to phophate group. which is bonded to another small polar molecule (choline, serine, inositol, ethanolamine)
how is sphingomyelin different then other phospholipids?
it is the only nonglycerol phospholipid. meaning the polar head group is formed from serine instead of glycerol
what is a glycolipid composed of?
two hydrocarbon chains and a carbohydrate polar head group
what is cholesterol composed of
four hydrophobic hydrocarbon rings and a polar hydroxyl (OH) group
the steriod hormones are derivatives of __________; that act as chemical messengers
cholesterol
what does DNA stand for?
deoxyribonucleic acid
what does RNA stand for?
ribonucleic acid
what does messenger RNA do?
carries information from DNA to the ribosomes
what does ribosomal RNA and transfer RNA do?
they are involve in protein synthesis.
still other _______ are involved in the regulation of gene expression and processing and transport of RNAs and protiens
other RNAS
DNA and RNA are polymers of ________ which consists of ___________- and _________ bases linked to a phosphorylated sugars
nucleotides
purine
pyrimidine
DNA has what two purines?
adenine and guanine
DNA has what two pyrimidines?
cytosine and thymine
RNA has what two purines?
adenine and guanine
RNA has what two pyrimidines?
cytosine and uracil
What do you call the sugar component in RNA?
ribose
what do you call the sugar component in DNA?
2’-deoxyribose