DNA and RNA Flashcards
what are the two types of nucleic acids
DNA and RNA
What are the monomers of dna called
nucleotides
what does each nucloetide of dna consist of
a nitrogenous base
deoxyribose sugar
a phosphate
where is DNA found and what is each dna called
nucleus- nuclear dna
chloroplast- chlorpoplastic dna
mitochondria- mitochondrial dna(mtDNA)
what is the structure of dna
double stranded
consisting of 2 nucleotides joined together by a week hydrogen bond
double helix shape
what are the two groups of nitrogenous bases and what do they consist of
purines- adenine and guanine
pyrimidines- cytosine and thymine
what are the pairs of nitrogenous bases
cytosine and guanine
adenine and thymine
the structure of dna is based off the model put together by who and when
watson and crick in 1953
why can dna be drown as a straight line
the sugar-phosphate backbone is consistent
what are the functions of dna
dna codes for the formation of different proteins required in the body
dna is responsible for transmitting hereditary characteristics from parent to offspring
what are the three types of rna and where are they found
-ribosomal rna (rRNA) found in ribosomes in cytoplasm
-messenger RNA (mRNA) found in nucleus but moves out of nucleus and attaches to ribosome in cytoplasm
-transfer RNA (tRNA) found in cytoplasm
what is the structure of rna
single stranded
sugar is ribose
thymine not uracil
bases are not paired
what is the function of rna
protein synthesis
what are the similarities between dna and rna
•both contain sugar alternating with phosphate
•both contain nitrogenous bases(adenine, guanine, cytosine)
•both play a role in protein synthesis
•both are composed of nucleotides
what are the differences between dna and rna
dna-found in nucleus, chloroplast and mitochondria
rna-found in nucleus and cytoplasm
dna-double stranded molecule
rna-single stranded molecule
dna-contains sugar deoxyribose
rna-contains sugar ribose
dna-contains nitrogenous base thymine
rna-contains nitrogenous base uracil
dna- very large
rna- small
what is dna replication
the process by which dna makes an identical copy of itself
when does dna replication occur
just before cell division (mitosis and meiosis) during interphase
how does dna replication occur
1- dna double helix unwinds
2- weak hydrogen bonds between nitrogenous bases break
3- two dna strands unzip
4- each dna strand acts as a template to form a new strand by attaching to free nucleotides in the nucleoplasm
5-this forms complementary strands
6- resulting in two genetically identical dna molecules
what is dna profiling used for
establishing a persons parents
tracing siblings
identifying people who have died by bodies which cannot be recognized
what happens in the first stage of protein synthesis
transcription- formation of messenger rna (mRNA)
-dna double helix unwinds
- weak hydrogen bonds between nitrogenous bases break
- forming two single strands of dna
one strand acts as a template
-to form complementary strand (mRNA)
using free rna nucleotides in cytoplasm
-three adjacent bases or mRNA make up a codon
-which codes for amino acids
what makes a codon and what do they code for
-three adjacent bases or mRNA make up a codon
-which codes for amino acids
what happens in the middle stage of protein synthesis
movement
-mRna moves out of nucleus through nucleopore into cytoplasm
- there it attaches to ribosome
what happens in the final stage of protein synthesis
translation - using info from mRNA to forma protein
-accoring to the codons of mRNA
-tRNA molecules with complementary anticodons bring required amino acid to ribosome
-amino acids link with peptide bonds
- this forms required proteins
