Biology DNA RNA Protein Test Study Guide

What is the function of the mRNA?

to carry protein information from the DNA in a cell's nucleus to the cell's cytoplasm

What is the function of the rRNA?

It is responsible for reading the order of amino acids and linking amino acids together.

What is the function of the tRNA?

They read codons on mRNAs and they deliver the appropriate amino acid to the ribosome for protein synthesis.

How does DNA control protein synthesis?

It can with the help of mRNA and tRNA.

What is a nucleic acid?

It is a large biomolecule that is a key component of all cells and viruses. A major function of them involves the storage and expression of genomic information.

What is a nucleotide?

An organic molecule made up of three parts

What type of macromolecule would an enzyme be classified as?

protein macromolecules

What is the template of the mRNA molecule?

The nucleotide sequence of DNA.

What is the function of a ribosome?

The cellular machinery responsible for making proteins. 1 is made up of two subunits, which lock around the messenger RNA and then travel along the length of the messenger RNA molecule reading each three-letter codon.

What is the monomer of a protein?

amino acids

What is an enzyme function?

They are proteins that act upon substrate molecules and decrease the activation energy necessary for a chemical reaction to occur by stabilizing the transition state. This stabilization speeds up reaction rates and makes them happen at physiologically significant rates.

What are 3 unique characteristics of RNA?

One stranded, has uracil (U) and has ribose sugar.

What nitrogenous bases pair with each other in DNA?

adenine always pairs with thymine (A-T), and guanine always pairs with cytosine (G-C).

What nitrogenous bases pair with each other in RNA?

adenine always pairs with uracil(A-U), and guanine always pairs with cytosine (G-C).

Where can DNA be found in the cell?

cell nucleus

What is the shape of a DNA molecule?

Double helix

What does the shape of DNA look like?

A spiraled/twisted ladder

When does gene expression begin?

Transcription, which is the first step in the process.

What is transcription?

The process by which the DNA sequence of a gene is copied into an RNA molecule. This process is carried out by an enzyme called RNA polymerase, which binds to the DNA strand and uses it as a template to synthesize a complementary RNA strand.

How is transcription carried out?

By an enzyme called RNA polymerase, which binds to the DNA strand and uses it as a template to synthesize a complementary RNA strand. The RNA strand is then released from the DNA strand and can be used to produce proteins.

What enzyme initiates the first stage of transcription?

RNA polymerase

What is the difference between an intron and an exon?

Introns are non-coding sequences within a gene that is removed during the RNA splicing process, so not expressed. Exons are the coding portions of DNA or RNA that are joined together by RNA processing to form the mature RNA, so expressed.

Where does transcription take place?

the nucleus of a cell

Where does translation take place?

the cytoplasm

What happens if a mutation occurs in a segment of DNA?

Could lead to genetic conditions like cancer, or have no effect, some rarely can be beneficial to helping humans adapt to their environment.

What substance attaches to a particular amino-acid molecule and positions it on a ribosome?

tRNA

What happens in the process of translation?

The cell uses information from the mRNA to produce proteins.

What are the products of transcription?

RNA, which can be encountered in the form mRNA, tRNA or rRNA

What are the products of translation?

a polypeptide amino acid chain, which forms a protein

What do genes contain?

Instructions that tells your cells to make molecules called proteins (from amino acids)

What happens in DNA replication?

The process by which a double-stranded DNA molecule is copied to produce two identical DNA molecules. Replication is an essential process because, whenever a cell divides, the two new daughter cells must contain the same genetic information, or DNA, as the parent cell.

Why is it possible for an amino acid to be specified by more than one codon?

Because there are only 20 different amino acids but 64 possible codons, most amino acids are indicated by more than one codon. (Note, however, that each codon represents only one amino acid or stop codon.)

What type of RNA functions as the blueprint for protein synthesis?

Specifically, mRNA carries the protein blueprint from a cell's DNA to its ribosomes, which are the "machines" that the process.

What are the purines in DNA and RNA?

adenine and guanine

What are the pyrimidines in DNA?

cytosine and thymine

What are the pyrimidines in RNA?

cytosine and uracil

What does a stop codon code for?

a halt to protein synthesis in the cell.

What portion of a tRNA molecule determines the type of amino acid that bonds with tRNA?

the anticodon

What type of bond is formed between amino acids?

peptide bond

How is a DNA segment transcribed and translated into mRNA, tRNA and amino acids? First step

Initiation, in which the enzyme RNA polymerase binds to a region of a gene called the promoter. This signals the DNA to unwind so the enzyme can ''read'' the bases in one of the DNA strands.

How is a DNA segment transcribed and translated into mRNA, tRNA and amino acids? Second step

Elongation, in which the mRNA is read one codon at a time, and the amino acid matching each codon is added to a growing protein chain.

How is a DNA segment transcribed and translated into mRNA, tRNA and amino acids? Third and final step

Termination, in which DNA synthesis is completed, the replication machinery is disassembled and daughter molecules are resolved.

What is the heritable genetic information found in an organism?

DNA, in the cell nucleus (where it is called nuclear DNA), but a small amount of DNA can also be found in the mitochondria (where it is called mitochondrial DNA), contains the code for building and maintaining an organism.

Which direction is DNA replicated from the point of origin?

Only replicated in the 5'-to-3' direction, for the need for accuracy, as if there there were a DNA polymerase that added DNTP's in the 3′-to-5′ direction, the growing 5′-chain end, would carry the activating triphosphate, rather than the incoming mono-nucleotide.

What direction are nucleotides added to the growing chain of DNA?

Only to the 3' end of the growing strand.

What are the nitrogen bases found in DNA?

adenine (A), thymine (T), cytosine (C), and guanine (G)

What are the nitrogen bases found in RNA?

adenine (A), uracil (U), cytosine (C), and guanine (G)

How many nucleotides make up a codon?

3 nucleotides

What are the enzymes called that make bonds between the nucleotides?

DNA polymerase

What is the difference between a codon and an anticodon?

An mRNA molecule carries codons, while a tRNA molecule carries anticodons.

Why are codons and anticodons said to be complementary?

They are to ensure the correct the amino acids are added to the growing polypeptide chain.

What is the key enzyme involved in transcription?

RNA polymerase

What is initiation?

A process in which the enzyme RNA polymerase binds to a region of a gene called the promoter. This signals the DNA to unwind so the enzyme can ''read'' the bases in one of the DNA strands.

What is elongation?

A process in which the mRNA is read one codon at a time, and the amino acid matching each codon is added to a growing protein chain.

What is termination?

A process in which DNA synthesis is completed, the replication machinery is disassembled and daughter molecules are resolved.

What is a nucleotide made of?

Aa nitrogenous base, a five-carbon sugar, and a phosphate group made up of one to three phosphates