Lecture 3a Flashcards
During transcription, what side of the RNA transcript are nucleotides added to?
The 3’ end.
What adds nucleotides to the RNA transcript and at what end?
RNA polymerase adds nucleotides to the 3’ end of the growing transcript.
What is a gene?
A section of DNA in a chromosome that is copied into RNA.
What does a gene do?
Codes for proteins.
What do RNAs code for?
Proteins.
What are RNAs that code for proteins called?
messenger RNAs’ or mRNAs’
What are tRNAs?
Small RNAs that hydrogen bond to the mRNA and carry amino acids.
What hydrogen bonds to the mRNA?
tRNAs.
What are on the ends of the tRNAs?
An anticodon on one end and an amino acid on the other end.
One amino acid lines up with how many nucleotides?
Three.
How many nucleotides code for how many amino acids?
3 nucleotides code for 1 amino acid.
What is the genetic code?
20 different amino acids that can be coded for by a code of 3 nucleotides.
How many possible amino acids are there?
20
Is there just one nucleotide sequence for an amino acid?
No, many amino acids have more than one nucleotide sequence to code for it.
What is a codon?
3 RNA nucleotides that base pair with 1 tRNA.
Where is the anticodon located?
On one end of the tRNA.
What does the anticodon bond to?
The codon on the mRNA.
How do the anticodon and codon bond?
Through hydrogen bonds.
Where is the codon located?
On the mRNA.
What is the ‘Start’ codon?
AUG
What happens when the anticodon and the codon bond?
The amino acids are linked together and detached from tRNAs.
What is a ribosome?
An enzyme that grows the amino acid together by adding the amino acid chain to the incoming amino acids.
What is responsible for growing the amino acid chain?
Ribosomes
What adds the amino acid chain to the incoming amino acids?
Ribosomes.
What is the relationship between amino acids?
Some amino acids attract each other while other amino acids repel each other.
What is the shape of the amino acid chain?
Folds up into a 3D shape.
Why is the amino acid chain folded up into a 3D shape?
Some amino acids attract each other while others repel each other.
T/F: Proteins do a wide variety of things.
True
What are 3 categories of proteins?
Structural proteins, enzymes, and regulatory proteins.
What do enzymes do?
Catalyze chemical reactions.
T/F: Genetic material (DNA) has to somehow be replicated and split for cell division.
True
What about DNA suggested how it was replicated?
The structure of it.
What is the basic process of DNA replication?
1) DNA strands are separated.
2) The strands are used as templates to assemble new polymers.
During DNA replication, what end are DNA nucleotides added to?
The 3’ end with the free sugar.
What is responsible for performing DNA replication?
DNA polymerase.
How long does it take to replicate human chromosomes?
About 8 hours.
What do we call the time it takes to replicate human chromosomes? Why is this name stupid?
The Synthesis Phase or the S Phase. The name was given before knowing that DNA synthesis is DNA sequence replication, otherwise it would’ve been called the Replication Phase.
In DNA replication, what does each DNA strand do?
Each DNA strand serves as a template for a new strand that can be synthesized by DNA polymerase.
What do we call RNAs that code for amino acid chains?
mRNAs.
What do every 3 nucleotides code for?
1 amino acid.
What are proteins?
Amino acid chains folded into 3D shapes.
