1.5 DNA and RNA (nucleic acids) Flashcards
What does DNA stand for?
Deoxyribonucleic acid
What does RNA stand for?
Ribonucleic acid
What are the two functions of DNA?
- replication
- protein synthesis
What are the three types of RNA?
-rRNA (ribosomal RNA)
-tRNA (transfer RNA)
-mRNA (messenger RNA)
Which is longer, DNA or RNA.
DNA
Which bases are pyrimidines?
Cytosine
Uracil
Thymine
Which bases are purines?
Adenine
Guanine
Complementary bases are linked by bonds, what type of bonds are these?
Hydrogen bonds
What does antiparallel mean?
Strands run in opposite directions while being parallel
What is the shape of DNA?
Double stranded, double helix
what is a purine?
two rings of carbon and nitrogen atoms
pyrimidines
a single ring of carbon and nitrogen atoms
what is nucleotide polymerisation
nucleotides join together via a condensation reaction (-H20)
what bonds form during nucleotide polymerisation
phosphodiester bonds (covalent)
where do phosphodiester bonds form
between phosphate group of one nucleotide and hydroxyl group on carbon 3 (of the sugar) of another
do bases take part in in polymerisation?
no. there is a sugar-phosphate backbone
what do many nucleotides form
a polynucleotide
describe the structure of DNA
- double stranded + wound to form double helix
- antiparallel, both strands joined by hydrogen bonds
- complimentary base pairs form
what is the function of DNA
(genetic material)
∴ replication + expression (protein synthesis)
what does replication mean
DNA must be copied every time a cell divides
what does expression mean
genes on DNA control characteristics.
what is a gene
a section of DNA which codes for a particular protein
what is transcription
making RNA
what is translation
making proteins
describe the structure of RNA
- single stranded
- shorter (than DNA)
DNA vs RNA
RNA has sugar ribose instead of deoxyribose
RNA has base uracil instead of thymine
RNA is single stranded
RNA is shorter than DNA
what is the function of mRNA
carries genetic code from DNA to ribosomes
what is the function of rRNA
ribosomes are the site of protein synthesis
what is the function of tRNA
transports amino acids to ribsomes
