Chapter 5 Flashcards
(345 cards)
Plant cell walls consist mainly of _____.
cellulose
Cellulose is a
polysaccharide that is a major component of the tough walls that enclose plant cells.
The characteristic that all lipids have in common is that _____.
none of them dissolves in water.
Almost all the covalent bonds in lipids are nonpolar, causing their
solubility in water to be extremely low.
Lipids are
hydrophobic substances.
Palm oil and coconut oil are more like animal fats than are other plant oils. Because they _____ than other plant oils, they may contribute to cardiovascular disease.
contain fewer double bonds
Evidence suggests that a diet high in saturated fats may contribute to
human cardiovascular disease.
Some regions of a polypeptide may coil or fold back on themselves. This is called _____, and the coils or folds are held in place by _____.
secondary structure … covalent bonds
Secondary structure is the
localized folding and/or coiling of the primary structure of a polypeptide. It results from hydrogen bonding between atoms of the polypeptide backbone.
A dehydration reaction (or condensation reaction) is the process in which _____.
water molecules are produced as a polymer is formed from monomers
Monomers are joined together in a
reaction in which two molecules are covalently bonded to each other through the loss of a water molecule; this is called a condensation reaction or, specifically, a dehydration reaction.
A hydrophobic amino acid R group (side group) would be found where in a protein?
on the inside of the folded chain, away from water
Hydrophobic R groups are
nonpolar. By orienting within the folded chain they associate with other nonpolar R groups or side chains and avoid coming into contact with water.
Sucrose is formed when glucose is joined to fructose by a(n) _____.
glycosidic linkage
Glycosidic linkages join
simple sugars to form polysaccharides.
The flow of genetic information in a cell goes from _____.
DNA to RNA to protein
The information in DNA is transcribed into
RNA and then translated into protein.
The building blocks or monomers of nucleic acid molecules are called _____.
nucleotides
A nucleotide is a
nucleic acid monomer consisting of a nitrogen base, a pentose sugar, and a phosphate group.
Nucleotides joined together by covalent bonds are called
phosphodiester linkages and form nucleic acid molecules.
The four main categories of large biological molecules present in living systems are _____.
proteins, nucleic acids, polysaccharides, and lipids
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Which polymers are composed of amino acids?
Proteins
Proteins are composed of
amino acids joined together.
Which of the following are attached to the central carbon atom in an amino acid?
A carboxyl functional group,
A side chain (“R group”)
and An amino functional group