Lecture 5 Flashcards
What is the purpose of nucleic acids?
they story and transmit hereditary information in genes
these genes, we call them units of what?
units of inheritance
Why are nucleic acids important for proteins?
b/c they ensure the sequence of a.a. for polypeptides chains
name the 2 types of nucleic acids
DNA and RNA
What does DNA stand for?
Deoxyribonucleic acid
What does RNA stand for?
Ribonucleic acid
What does DNA do?
it stores info for protein synthesis
what does RNA do?
it directs protein synthesis
Which one act as blueprints to make various proteins in our cells?
DNA
which one acts like messengers to relay info?
RNA (specifically, mRNA)
Do both DNA and RNA have Phosphate?
YES
Do both DNA and RNA have Sugar?
yes but different
DNA: Deoxyribose
RNA: Ribose
What are the bases of DNA?
Adenine
Thymine
Cytosine
Guanine
What are the bases of RNA?
Adenine
Uracil
Cytosine
Guanine
Which one is double and one stranded
DNA: double-stranded
RNA: single-stranded
Name all 3 types of RNA involved in protein synthesis
mRNA
tRNA
rRNA
Why is DNA essential? (2)
it’s need for cell replication + it contains genes
How long is DNA?
over 2m long
Is the sequence of nucleotides are different, it means that….
the proteins are different (different functions)
Each what carries information?
each gene (lowkey like a blueprint)
Genes carry information that determines what of the protein?
the primary sequence of the protein
What are the 2 major steps in protein synthesis?
Transcription and translation
Transcription goes from DNA to what?
then translation, what to waht
DNA to RNA
RNA to protein
What is transcription?
transfer of genetic information from DNA to mRNA (messenger RNA)
What is a mRNA?
it’s a single-starnded molecule that is synthesized in the nucleus
mRNA are organized in group of what?
3 nucleotides
what are these 3 nucleotides called?
codon
So what is basically happening to the DNA template strand?
the strand is being copied (into mRNA)
When is this process over (transcription over)?
once the mRNA molecule is complete
Then the second part of protein synthesis starts, what is the name step?
translation
What is translation?
the assembly of the protein primary structure
How many amino acid to create a primary structure of the protein?
7 amino acids
What is the start codon called?
Methionine
do we count the last codon?
NO, it’s called a stop codon (it’s indicating in the table with all the different amino acids possible)
Which type of RNA is important in this process?
tRNA (transfer RNA)
What does a tRNA have?
anticodons (to complement the mRNA codons)
AAG would paire with which codon?
UUC
Why are ribosomes important in protein synthesis?
because it happens in the ribosome, it links mRNA and tRNA to make a protein
The ribosome is separated in how many sections?
3 = E-P-A
Where does the first (start codon) attaches to?
the P site
Why is it like a zipper?
b/c p goes to e
and a goes to p
E <– P <– A <–
Make a general/ easy summary of translation
- tRNA with anticodon matches mRNA codon
- a.a. from tRNA linked to growing a.a. chain
- tRNA is released and ribosome moves along mRNA chain
What releases the polypeptide?
once a protein called release factor binds to A site, it causes a water molecule to hydrolyze the chain form tRNA in P site
so elongation occurs until stop codon arrives at site A (UAG, UAA or UGA)
