Nucleic Acids Details Flashcards
Which molecule is used as genetic material in all living organisms?
DNA(deoxyribonucleic acid)
Types of nucleic acids
-DNA(deoxyribonucleic acid)
-RNA(ribonucleic acid)
Components of nucleotides
-a pentose sugar(with five carbon atoms and a five-atom “ring”)
-a phosphate(acidic and negatively charged part of nucleic acids)
-a base(containing nitrogen and has either one or two rings of atoms in its structure)
Bases can be arranged in any sequence along a strand of molecules(T/F)
True
Bases in DNA
-Adenine(A)
-Cytosine(C)
-Guanine(G)
-Thymine(T)
Bases in RNA
-Adenine(A)
-Cytosine(C)
-Guanine(G)
-Uracil(U)
Why are bases sometimes called nitrogenous bases
They all contain nitrogen
The nucleotides in a strand of DNA or RNA are linked together by…
covalent bonds(between the pentose sugar and the phosphate of the next one)
The sequence of bases is how genetic information is stored(T/F)
True
Number of strands of nucleotides in RNA
1
Number of strands of nucleotides in DNA
2
Why is the bonding of the pentose sugar(of one nucleotide) to phosphate(of the next one) a condensation reaction?
Water is a product of the reaction
Complementary base pairs in DNA
-Adenine with Thymine(A-T)
-Cytosine with Guanine(C-G)
Properties of the 2 strands in DNA
-Antiparallel(run alongside each other but in opposite directions)
-Wound together to form a double helix
DIffrences between DNA and RNA
-The pentose sugar is ribose in RNA but deoxyribose in DNA
-DNA has the base thymine but RNA has uracil instead
-RNA usually has one strand of nucleotides while DNA usually has two
Roles of complementary base pairing in cells
-DNA replication(so genetic information can be passed on to daughter cells)
-Transcription
-Translation
Capacity of DNA to store information
Effectively limitless; since bases can be arranged in any sequence in DNA(and genes alone have thousands of bases)
Number of different codons
64(this is because each base in a codon can be any of four, so there are 4×4×4 combinations)
Meaning of each of the 64 codons
-Most codons specify one particular amino acid(i.e. add a specific amino acid to the polypeptide chain)
-One codon signals that protein synthesis should start
-Three codons signal that protein synthesis should stop
Why is genetic code considered universal
All organisms use the same genetic code(all species use the same four bases A,T,C and G, and each base sequence codes for the same amino acid in all species) with only minor variations
Implications of the universality of the genetic code
All life evolved from the same original ancestor, with minor differences added since then
