A1.2 - nucleic acids (2b) Flashcards
what is a dna nucleotide?
a DNA monomer composed of a phosphate group, pentose sugar and base joined by covalent bonds
what are the 4 different bases?
- adenine
- cytosine
- guanine
- thymine or uracil (in RNA)
what are the 2 types of genetic material?
where are they located?
DNA is the genetic material of all living organisms
- some viruses use RNA as their genetic material but viruses are not considered to be living
why are multiple bases required?
multiple bases are required as the bases form the foundation of the genetic code
what is a pentose sugar?
a pentose sugar contains 5 carbon atoms
what is the name of the pentose sugar found in DNA and RNA?
DNA - deoxyribose
- it has one less O than ribose
RNA - ribose
what structures are formed by joining nucleotides in the backbone of DNA and RNA?
sugar–phosphate bonding makes a continuous chain of covalently bonded atoms in each strand of DNA or RNA nucleotides, which forms a strong “backbone” in the molecule
- the pentose sugar of one nucleotide is covalently bonded to the phosphate group on the next nucleotide
how are nucleotides joined together?
nucleotides are joined by condensation reactions between monomers to form a polymer
- this forms a strong covalent bond between the pentose sugar on one nucleotide and the phosphate group of another nucleotide
- a molecule of water is released
what is the structure of DNA?
DNA is a double helix made of two antiparallel strands of nucleotides with the strands linked by hydrogen bonding between complementary base pairs
what are differences between the structures of DNA and RNA?
DNA:
- double stranded
- deoxyribose sugar
- adenine, thymine, guanine, thymine
- helical structure
RNA:
- single stranded
- adenine, thymine, guanine, uracil
- ribose sugar
- variety of forms: mRNA, rRNA, tRNA
what is DNA?
DNA is a long-term hereditary storage molecules for all living organisms
what is mRNA?
messenger RNA is synthesized using one gene as a template, in a process called transcription, and it then leaves the nucleus and brings the genetic information to the ribosome
what is rRNA?
ribosomal RNA are components of ribosomes, which carry out translation
what is tRNA?
transfer RNA brings the correct amino acid to add to a growing chain of amino acids at the ribosome, during translation
what is ATP?
adenosine triphosphate (ATP) is a single-nucleotide nucleic acid comprised of adenine, ribose and three phosphate groups
- ATP is used as a short-term store of chemical energy
