biochem nucleutides, nucleic acids and heredity Flashcards
that the transmission of hereditary information took place in the nucleus, more specifically in structures called
chromosomes.
Chemical analysis of nuclei showed chromosomes are made up largely of proteins called
histones and nucleic acids.
The hereditary information was thought to reside in genes within the
chromosomes
By the 1940s, it became clear that ____carry the hereditary information
deoxyribonucleic acids (DNA
There are two kinds of nucleic acids in cells:
- ribonucleic acids (RNA)
- deoxyribonucleic acids (DNA)
*Purine
-Adenine (A)
-Guanine (G)
Both RNA and DNA are polymers built from monomers called
nucleotides.
- There are two kinds of nucleic acids in cells:
- ribonucleic acids (RNA)
- deoxyribonucleic acids (DNA)
*Pyrimidine
-Cytosine (C)
-Thymine (T)
-Uracil (U)
- A nucleotide is composed of
: a base, a monosaccharide, and a phosphate.
Nucleosides: composed of
base and monosaccharide
: a compound that consists of D-ribose or 2-deoxy-D-ribose bonded to a purine or pyrimidine base by a B-N glycosidic bond.
- Nucleoside:
is esterified with an -OH of the monosaccharide
a nucleoside in which a molecule of phosphoric
a nucleoside in which a molecule of phosphoric
esterified with an -OH of the monosaccharide
-a nucleoside in which a molecule of phosphoric acid is esterified with an -OH of the monosaccharide, most commonly either the
3’ or the 5’-OH.
base sequence is read from the
5’ end to the 3’ end
serves as a common currency into which energy gained from food is converted and stored.
adenosine 5’-triphosphate (ATP)
: the ordered arrangement of nucleic acid strands.
Secondary structure
a type of 2° structure of DNA in which two polynucleotide strands are coiled around each other in a screw-like fashion.
- Double helix:
DNA is coiled around proteins called
histones.
Histones are rich in these basic amino acids
Lys and Arg
Lys and Arg
whose side chains have a positive charge.
The negatively-charged DNA molecules and positively-charged histones attract each other and form units called
nucleosomes
Nucleosomes are further condensed into
chromatin.
a core of eight histone molecules around which the DNA helix is wrapped
Nucleosome
Chromatin fibers are organized into
loops
DNA bases are
A, G, C,
. Chromatin fibers are organized into loops, and the loops into the bands that provide the superstructure of
chromosomes.
The sugar in DNA is
2-deoxy-D-ribose
T; the RNA bases are
A, G, C, and U
- The three differences in structure between DNA and RNA are:
- The three differences in structure between DNA and RNA are:
- DNA bases are A, G, C, and T; the RNA bases are A, G, C, and U.
- The sugar in DNA is 2-deoxy-D-ribose; in RNA it is D-ribose.
- DNA is always double stranded; there are several kinds of RNA, all of which are single-stranded.
The sugar in RNA is
D-ribose.