Biology Study Guide: Transcription and Translation

Be able to make a RNA nucleotide sequence that would be complementary to a GTAGTCA DNA strand.
CAUCAGU

The main function of tRNA is to:
Transfer amino acids/ribosomes for protein synthesis.

What is the term for a three-nucleotide sequence that codes for an amino acid?
Codon

How many amino acids are used to make up all the proteins in the human body?
20

A tRNA that carries the amino acid methionine pairs with which type of codon?
The start codon

Translation converts mRNA into __________.
proteins

Where is the site of translation (where does translation occur)?
Cytoplasm at ribosomes

In a eukaryotic cell, where does mRNA transcription take place?
Nucleus

Generally mutations that affect a single gene occur during __________.
DNA replication

What type of mutation is caused by the deletion of a nucleotide?
Frameshift

Mutations that can affect the offspring of an organism occur in what cell type>
Gametes or sex cells

This is a single strand of RNA- AUCUCAG. Choose the first three nucleotides of the complementary tRNA strand.
UAG

During transcription, what does messenger RNA do:
It is copied from DNA

In order to produce all the protein that a cell needs, transcription takes place on a gene segment over and over again.
True

How many amino acids are coded for by the strand of mRNA? GCUAUG
2

How does the ribosome interact with mRNA and tRNA during translation?
It reads the codons on the mRNA and allows the tRNA to enter so it can match with the mRNA and drop the amino acid it is carrying.

Suppose insertion mutation occurred in a coding region of mRNA. How would it affect the structure of the resulting protein?
It would change the amino acid, making it a different protein.

If insertion mutation occurred in a body cell would the offspring be affected? Explain.
No, the offspring are only affected if gametes (sex cells) are mutated.

State 3 ways RNA is different from DNA.
Single Strand
Ribose Sugar
Uracil

Name three types of RNA and give the function of each type.
mRNA: carries the code from DNA to the ribosome
tRNA: brings amino acid to ribosome to start making protein
rRNA: glues the codon and anticodon together so the amino acid chain can start being built.

Describe the process of translation:
mRNA carries the protein code, in the form of codons, to the ribosome, the ribosome reads the codon and signals the tRNA with the corresponding anticodon to match up with the codon, rRNA binds the codon and anticodon together releasing the amino acid the tRNA is carrying stating the protein chain, the process repeats until the stop codon is reached finishing the protein building process.

Explain how the sequence of bases in DNA determines the amino acid sequence in the protein.
Each set of 3 nitrogen bases is called a codon. A codon has the code for an amino acid, so however many codons there are is how many amino acids will be used.

(AAGTTTGGTTACTTC)
What is the mRNA sequenced transcribes from this DNA?
UUCAAACCAAUGAAG

(UUCAAACCAAUGAAG)
What is the amino acid sequence translated from this mRNA?
Phenylalanine, lysine, proline, methionine, lysine

Describe in some detail how the genetic code is read by the ribosome. In doing so explain the terms codon, anticodon, start codon, and stop codon.
mRNA brings the codon, which is the code for amino acid. The first codon needed to make a protein is a start codon. The tRNA brings the matching anticodon and then released the amino acid and this process continues until a stop codon is reached.

What agents can cause mutations?
Mutagens

What is the significance of having 64 codons in the genetic code? What is the value, if any, in the redundancy in the code?
By having more than one codon for several of the amino acids, this allows possible mutations to have less effect on proteins being made. If any mutation occurs but the changed codon still codes for the same amino acid, the organism will not be affected by the mutation.

List 2 types of gene mutations.
Gene & Chromosomal

List 2 types of chromosomal mutations:
Point Mutation
Deletion
Insertion
Substitution

Which type of mutation affects more genes, a gene mutation or a chromosomal mutation?
Chromosomal, it will affect several genes instead of just one.

What leads to gene duplication?
Non-disjunction of chromosomes, error in copying of chromosomes.

What is translocation?
The loss of part of one chromosome and it being attached to another chromosome.

What are operons?
Areas of DNA that code for a specific protein.

What are repressors?
Proteins that bind to DNA to keep proteins to be coded for.

What is gene expression?
Making of a particular protein.

What is gene regulation?
How often or how many proteins are made or just when the proteins are made.