Chapter 13: RNA and Protein Synthesis Question from Notes Flashcards
Name the bases of DNA.
Adenine, Thymine, Guanine, Cytosine
Name the bases of RNA.
Uracil, Adenine, Guanine, Cytosine
A _______ usually ends with “ase.”
enzyme
What is the construction block for protein synthesis?
protein
_________ make up DNA.
Nucleotides make up DNA.
Nucleotides are made up of a nitrogenous base, C5 sugar (deoxyribose), and a _________ group.
phosphate
What is the genetic material of cells?
DNA
What carries the code to instruct what proteins (RNA) will be made?
the sequence of nucleotide bases in the strands of DNA
True or False: Nothing happens in the cell without the nucleus being involved.
True
Ribosomes only understand the language of ___.
Ribosomes only understand the language of RNA.
What are the three important differences between RNA and DNA?
- The sugar in RNA is ribose instead of deoxyribose.
- RNA is generally single-stranded, rather than double-stranded.
- RNA contains uracil in place of thymine.
_____ contain coded DNA instructions that tell cells how to build proteins.
Genes
What is the first step in decoding the DNA genetic instructions?
copy part of the base sequence from DNA into RNA
What is the name of the signal that starts the protein construction and tells the RNA polymerase where to begin?
a promoter
What will always be the start codon (promoter) for proteins?
methionine (AUG)
RNA, like DNA, is a ______ ___.
nucleic acid
What makes it easy for the enzymes in the cell to tell DNA and RNA apart?
The chemical differences between the RNA and DNA
DNA is similar to the _______, while RNA is similar to the _________ in a construction job.
DNA is similar to the master plan, while RNA is similar to the blueprint in a construction job.
Where does RNA go?
the protein-building sites in the cytoplasm, the ribosomes
Most RNA molecules are involved in _______ _______ only.
Most RNA molecules are involved in protein synthesis only.
RNA controls the assembly of ______ _____ into proteins.
amino acids
What are the three main types of RNA?
- ) messenger RNA
- ) ribosomal RNA
- ) transfer RNA
What binds to DNA during transcription and then separates the two strands?
RNA polymerase
Most genes contain instructions for what?
assembling amino acids into proteins
Messenger RNA carry what?
Messenger RNA carry information (the instructions) to other parts of a cell.
*take the message from the DNA out of the nucleus
Where are proteins assembled?
ribosomes
Ribosomes are made of two subunits. These subunits are composed of several ________ ___ molecules, and 80 different proteins.
Ribosomes are made of two subunits. These subunits are composed of several ribosomal RNA molecules, and 80 different proteins.
Transfer RNA transfers each what to the ribosome?
each amino acid
How does the tRNA know what amino acid to transfer?
the tRNA follow the coded message in the mRNA
In transcription, segments of ___ serve as templates to produce complimentary ___ molecules.
In transcription, segments of DNA serve as templates to produce complimentary RNA molecules.
Most of the work of making RNA takes place during _________.
Most of the work of making RNA takes place during transcription.
RNA synthesis and protein synthesis take place in the cytoplasm of _________.
prokaryotes
In eukaryotes, RNA is produced in the cell’s ______.
nucleus
In eukaryotes, the newly-made RNA then moves where to play a role in the production of proteins?
the cytoplasm (ribosome)
RNA polymerase binds only to ________.
promoters
The portions of RNA molecules that are cut out and discarded are called ______.
The portions of RNA molecules that are cut out and discarded are called introns.
In order to get the needed end result, the ______ cleans out the RNA coding.
nucleus
In eukaryotes, introns are taken out of ____ -___ molecules while they are still in the nucleus.
pre- mRNA
The remaining pieces of the RNA, the _____, are spliced back together to form mRNA.
The remaining pieces of the RNA, the exons, are spliced back together to form mRNA.
True or False: Introns and eons definitely do not play a role in evolution.
False
Where can ribosomes be found?
On the surface of the rough endoplasmic reticulum, or freefloating
What is dehydration synthesis?
When bonds of amino acid break, water is released.
The genetic code is read _ “letters” at a time.
3
Each “word” to the genetic code is three bases long and corresponds to what?
A single amino acid
What is the first step in decoding genetic messages?
Transcribe a nucleotide base sequence from DNA to RNA
What bonds every amino bonds every amino acid?
A peptide bond
Proteins are made by joining amino acids together into long chains called ___________.
Proteins are made by joining amino acids together into long chains called polypeptides.
The specific amino acids in a polypeptide, and the order in which they are joined determine what?
the properties of different proteins
What determines the shape (and structure) of a protein?
the sequence of amino acids
Each three-letter (base) word in mRNA is known as a what?
codon
A codon specifies a single _____ ___ to be added to the polypeptide chain.
amino acid
How many possible three-base codons are there in the genetic code?
64
4 different bases, 3 bases
4x4x4= 64
True or False: Many amino acids can be specified by more than one codon.
True
How many different stop codons are there?
Three
Ribosomes use the sequence of ______ in mRNA to assemble amino acids into polypeptide chains.
Ribosomes use the sequence of codons in mRNA to assemble amino acids into polypeptide chains.
Ribosomes do not understand what language?
mRNA
Ribosomes do understand what language?
tRNA
The decoding of an mRNA message into a protein is a process known as what?
translation
Where is mRNA transcribed?
in the nucleus
After transcription, mRNA enters where?
the cytoplasm
When does translation begin?
when a ribosome attaches to an mRNA molecule in the cytoplasm
As the ribosome reads each codon of mRNA, it directs _____ to bring the specified ______ ___ into the ribosome.
As the ribosome reads each codon of mRNA, it directs tRNA to bring the specified amino acid into the ribosome.
Then, the ribosome attaches each amino acid to the growing _____.
chain
True or False: Each tRNA molecule carries just one kind of amino acid.
True
In addition to one type of amino acid, each tRNA molecule has three unpaired bases collectively called the _________.
In addition to one type of amino acid, each tRNA molecule has three unpaired bases collectively called the anticodon.
The anticodon is complementary to one ____ codon.
The anticodon is complementary to one mRNA codon.
If the next codon is UUC, a tRNA molecule with an ___ anticodon brings the matching amino acid, phenylalanine, into the ribosome.
AAG
The ribosome helps form a peptide bond between what?
the first and the second amino acids
The tRNA molecule then moves into a third bonding site, where it _____ the ribosome.
The tRNA molecule then moves into a third bonding site, where it exits the ribosome.
The polypeptide change continues to grow until the ribosome reaches a what?
“stop” codon on the mRNA molecule
What does the ribosome release after it reaches the “stop” codon?
- the newly formed polypeptide
- the mRNA molecule
this completes the process of translation
If you were to read for the amino acid, what would you read?
the actual codon
The rRNA molecules in ribosomes help hold the _______ ______ in place and help locate the beginning of the mRNA message.
The rRNA molecules in ribosomes help hold the ribosomal proteins in place and help locate the beginning of the mRNA message.
What is the “central dogma” of molecular biology?
Information is transferred form DNA to RNA to protein
True or False: Most genes do not contain instructions for assembling proteins.
False
What is the way in which DNA, RNA, and proteins are involved in putting genetic information into action in living cells?
Gene expression
What are mutations?
Mistakes in the genetic coding
What are the two basic categories of mutations?
- Gene mutations
2. Chromosomal mutations
Mutations that involve changes in the number or structure of chromosomes are called ___________ mutations.
chromosomal
Mutations that produce changes in a single gene are known as ____ mutations.
gene
Mutations that involve changes in one or a few nucleotides and occur at a single point in the DNA sequence are known as what?
point mutations
Point mutations generally occur during replications of ___.
DNA
True or False: If a gene in one cell is altered, the alteration can be passed on to every cell that develops from the original one.
True
Name the three types of point mutations.
substitutions, insertions, and deletions
True or False: Substitution changes the resulting amino acid.
True
What happens in a substitution?
One base is changed to a different base
Do substitutions affect many amino acids.
No, sometimes they have no effect at all.
What are insertions and deletions?
Point mutations in which one base is inserted or removed from the DNA sequence.
How do insertions and deletions change the reading of the codons?
The bases are still read in groups of three, but now those groupings shift in every codon that follows the mutation.
The shift of the “reading frame” that is caused by insertions and deletions is called a ________ ________.
The shift of the “reading frame” that is caused by insertions and deletions is called a frameshift mutation.
What are the two types of frameshift mutations?
insertions and deletions
What are the four types of chromosomal mutations?
deletion, duplication, inversion, and translocation
Deletion involves the loss of ___ or ____ of a chromosome.
Deletion involves the loss of all or or of a chromosome.
What does duplication produce?
an extra copy of all or part of a chromosome
________ reverses the direction of parts of a chromosome.
Inversion
What is something that causes change (inspires a mutation)?
A mutagen
What occurs when part of one chromosome breaks off and attaches to another?
Translocation
An example of a chromosomal mutation is what?
Down’s syndrome
What type of RNA leaves the nucleus?
Messenger RNA
What RNA gets the transfer RNA’s attention?
Ribosomal RNA
Where does transcription take place?
in the nucleus
tRNA is the translator for ____.
mRNA
What is a product of translation?
water (from dehydration synthesis)
Where does the water from translation go?
Into the cytoplasm
True or False: Mutations have little or no effect, but some can be harmful or beneficial.
True
Small changes in genes gradually accumulate over time– this refers to what?
adaptations
