Nucleic acids and protein synthesis Flashcards
Structure of nucleotides
A nucleotide is an organic molecule that is the building block of DNA and RNA. A nucleotide is made up of three parts: a phosphate group, a 5-carbon sugar, and a nitrogenous base.
Structure of RNA (ribonucleic acid)
An important biological macromolecule that is present in all biological cells. RNA consists of ribose nucleotides (nitrogenous bases appended to a ribose sugar) attached by phosphodiester bonds, forming strands of varying lengths.
Structure of DNA (deoxyribonucleic acid)
A molecule that contains the instructions an organism needs to develop, live and reproduce. A molecule of DNA consists of two strands that form a double helix structure.
Importance of base pairing
Complementary base pairing is very important in the conservation of the base sequence of DNA. This is because adenine always pairs up with thymine and guanine always pairs up with cytosine.
Semi-conservative replication of DNA during interphase
The method of DNA being able to replicate itself. During interphase, cellular organelles double in number, the DNA replicates and protein synthesis occurs.
Polypeptides
They are coded by genes.
What is a gene?
A sequence of nucleotides that forms part of a DNA molecule.
What is a gene mutation?
A change in the sequence of nucleotides that may result in an altered polypeptide.
Way in which the nucleotide sequence codes for the amino acid sequence in a polypeptide
With codons. A codon is a sequence of three DNA or RNA nucleotides that corresponds with a specific amino acid or stop signal during protein synthesis. The genetic code includes 64 possible permutations, or combinations, of three-letter nucleotide sequences that can be made from the four nucleotides.
How is the information in DNA used during transcription to construct polypeptides?
Basically DNA makes RNA, and RNA makes protein. Transcription produces single-stranded RNA that is complementary to one strand of DNA.
How is the information in DNA used during translation to construct polypeptides?
Transfer RNA (tRNA) transports activated amino acids to the ribosomes to be used in assembling the protein molecule during translation.
