nucleic acids and their role in protein synthesis #1 Flashcards
ECP
what is DNA and RNA made up of
repeated monomers called nucleotides
polomer
many DNA
monomer
one nucleotide
what does DNA contain
-Nitrogenous base (A,T,G,C)
-Phosphate
-Deoxyribose sugar
Purine
- Large
- 2 rings
- A, G
phospho-diester bonds
bonding of the phosphate and deoxyribose sugar bond to form backbone of molecule
Pyrimidine
- Small
- 1 ring
-T, C
Purine and Pyrimidine
each complementary pair consists of one purine and one pyrimidine
5’
the end with the phosphate as the last molecule
3’
the end with the deoxyribose sugar molecule
chromosomes
DNA wrapped around proteins called histones
nucleosomes
DNA and histones together
protease
breaks down proteins
structure of chromosomes
double stranded DNA wrapped around histones. the DNA and histones and called nucleosomes. -They fold into structures called chromosomes.
genes
- section of chromsome
- gives instructions to make a protein or an RNA molecule
- codes for a trait
- what the offspring inherits
structure of RNA
- Nitrogenous base (A,U,C,G)
- Phosphate
- Ribose sugar
difference between RNA and DNA
- the types of bases
- the type of sugar
- DNA is double stranded and RNA is single stranded
differences between a monomer of DNA and RNA
- RNA has base pairs of A-U, G-C whereas DNA has base pairs of A-T, G-C
- DNA contains fewer oxygen as it contains deoxyribose sugar whereas RNA contains ribose sugar.
the 3 forms of RNA
- mRNA (messenger)
- tRNA (transfer)
- rRNA (ribosomal)
mRNA
- linear molecule
- takes the genetic code from the nucleus to the ribosomes in the cytosol
-by making copies
tRNA
- clover shaped molecule
- brings the SPECIFIC amino acid to the ribosome during protein formation
rRNA
- folded molecule
- forms part of a ribosome -is needed for translation to occur
if bases are complementary
amino acids will be sent down
gene expression
“turning on” a gene and making the proteins
- occurs through translation
- can turn on and off
- breast milk, pregnancy, puberty
- our eyeball does have the gene in it to grow a nail- turns off
triplet
3 DNA bases
when do u have to find complementary base pairing
when it is in DNA form not RNA
transcription
process of making a copy
codon
3 mRNA bases
degenerate or redundant
some amino acids are coded by more than one codon
what does every gene has to start with
AUG (met)
the 3 processes of making a protein
- transcription
- RNA processing
- translation
DNA contains instructions to make a protein but never leave the nucleus.
- how does the info get out of the nucleus?
a strand of mRNA which is made during transcription
- makes a copy of DNA info
- transfers to ribosomes to construct proteins.
where does RNA polymerase attach
the DNA at the start of the gene.
- the promotor region (TATA box)
what does the RNA polymerase do
- first attaches to the DNA at the start of the gene, attaching to the promotor region.
unwinds the double helix - passes over the template strand
- reads 3’ to 5’
what does the RNA polymerase do. pt 2- where are the nucleotides added to
nucleotides are added to the 3’ end of the RNA
- then, the double helix is rewound after that section has been transcribed
*the double helix is unwound due to the RNA polymerase enzyme
when does transcription stop
when the RNA polymerase reaches the termination region of the gene, containing the stop triplet
RNA
a type of nucleic acid
polymer
a large molecule made up of monomers
-ase
an enzyme
RNA polymerase
an enzyme involved in making a polymer of RNA
the parts of a eukaryote gene
- start and stop triplet
- promotor region (TATA box)
- exons
- introns
start and stop triplet
where coding for protein synthesis starts and stops
promotor region (TATA box)
a section before the gene with lots of A’s and T’s where the RNA polymerase attaches
exons
provide code for the proteins (ribosomes read)
- found in mature mRNA
- exits the nucleus
introns
- junk DNA
- do not provide code.
- are cut out before the final mRNA strand is made
what mRNA drops off the DNA
primary mRNA or pre- mRNA
mRNA processing- before is leaves the nucleus
- introns are cut out
- a G cap is added (ALWAYS GUANINE)
- a poly -A tail is added
translation
the production of a protein using the information provided by the mRNA
translation- how is it read
the ribosome reads the mRNA 3 bases (one codon) at a time.
what happens next in translation
the tRNA molecules with the complementary anticodon attaches to the codon
- the tRNA brings a SPECIFIC amino acid to the ribosome. (for example gyl, lye, ect.)
translation- what if it doesn’t match up?
it will detach and go into the cytosol
once the amino acid is released from the tRNA….
it is added to the growing polypeptide chain
what holds these amino acids together when they are added to the polypeptide chain
peptide bonds
when is the polypeptide chain released
when the stop codon is reached
correct terms for ‘3 bases’ for DNA, mRNA and tRNA
DNA- triplet
mRNA- codon
tRNA- anti codon
