DNA and RNA
Terms in this set (45)
What does DNA code for?
What are proteins made up of ?
Long chains of amino acids
What are the nitrogenous bases found in
Adenine, Guanine, Thymine, and Cytosine
What is the backbone of DNA made up of?
Deoxyribose and Phosphate
What do the rungs of DNA consist of?
What is the process by which the genetic code of DNA is copied into a strand of RNA is called?
The process by which DNA makes a copy of itself is called?
What chemical carries DNA's message to the ribosome?
Which of the following ways does RNA differ from DNA?
RNA contains uracil and ribose
The process by which proteins are made from mRNA is called?
Why is the genetic code universal?
The same codon makes the same amino acid in different organisms.
During transcription which sequence of nucleotides would bond with the DNA sequence TATGA?
Which of the following represents the codons that correspond to this segment of DNA: TAT-CAG-GAT?
What are chromosomes made up of?
What is replication?
It results in two DNA molecules that are identical to the original DNA molecules
What does tRNA do?
It transfers amino acids to a growing protein chain on the ribosome.
A cell's DNA contains a code that gives directions for the construction of _________________.
What is DNA?
Deoxyribonucleic acid, or DNA, is a nucleic acid macromolecule made of sugar-phospate units and nitrogenous bases.
What is the structure of DNA?
1. Double helix
3. Nitrogenous bases
4. Hydrogen bonding
5. Base pairing
What are nucleotides?
1. a five-carbon sugar called deoxyribose
2. a phosphate group
3. a nitrogenous base
The nucleotides in a DNA strand are held together by covalent bonds between the sugar of one nucleotide and the phosphate group of the next.
Name the 4 nitrogenous bases that make up DNA.
The four different nucleotides can be strung together in a variety of sequences to provide a different code.
What do the nitrogenous bases look like?
They resemble rungs on the DNA ladder.
What type of bonding is used between the nitrogenous bases of DNA?
Provides just enough attraction to hold the two strands together. Hydrogen bonds are weaker than covalent bonds.
What would happen if the nitrogenous bases were held together by covalent bonds instead of hydrogen bonds?
The strands would be very difficult to separate. The ability to separate the two strands of DNA is essential to the molecule's functions.
Hydrogen bonds will only form between certain base pairs. What are the 2 pairs?
guanine with cytosine (GC)
adenine with thymine (AT)
Nucleotides are held together by what type of bond?
hydrogen or covalent
Nitrogenous base pairs are held together by what type of bond?
hydrogen or covalent
What is replication?
Copying of DNA during interphase before cell division occurs.
How is DNA replicated?
The DNA molecule separates into two strands and then follows the rules of base pairing to build two new complementary strands. The nitrogenous bases on the original strands code for the arrangement of nucleotides in the new strands. For example, if the original strand contains guanine, then cytosine is added opposite it in the newly forming strand.
What is the purpose of enzymes during DNA replication?
Enzymes break the hydrogen bonds between the nitrogenous base pairs to separate the DNA strands.
Another enzyme called the DNA polymerase joins the new strands of DNA.
What is the complementary DNA strand for adenine (A)?
What is the complementary DNA strand for guanine (G)?
What is the complementary strand for thymine (T)?
What is the complementary strand for cytosine (C)?
Name 3 differences between RNA and DNA.
1. RNA is single-stranded, and DNA is double-stranded.
2. The sugar in RNA's nucleotides is ribose instead of deoxyribose.
3. RNA contains the nitrogenous base uracil instead of the thymine in DNA.
What is RNA?
What is the purpose of RNA?
Ribonucleic acid (or RNA), copies sections of the DNA molecule, and then carries the copies to the ribosomes where proteins are constructed. (synthesized)
What are 3 types of RNA that have a role in protein synthesis?
Messenger - mRNA - carries copies of instructions to other parts of the cell.
Transfer - tRNA - Transfer RNA (tRNA) molecules transfer each amino acid to the ribosomes according to the coded instructions provided in the mRNA.
Ribosomal - rRNA - Ribosomes subunits are made up of several ribosomal RNA (rRNA) molecules and up to 80 protein molecules where proteins are made.
What are the nitrogenous bases of RNA?
The nitrogenous bases of RNA are the same as DNA except RNA has uracil instead of thymine.
What is the complementary RNA strand for adenine (A)?
What is the complementary RNA strand for uracil (U)?
What is the complementary RNA strand for guanine (G)?
What is the complementary RNA strand for cytosine (C)?
What is transcription?
1. The DNA unzips like it did during DNA replication. One strand of DNA is "transcribed" or "copied" to make a messenger RNA (mRNA) molecule. The nitrogenous bases pair up. Uracil is now paired up with adenine for RNA.
2. Once the mRNA has transcribed the message, it breaks away from the DNA strand. The DNA then "rezips" back to its double helix shape.
3. The mRNA will carry the instructions from the nucleus to the cytoplasm for protein synthesis at the ribosomes.
What is translation?
The process of forming a protein chain of amino acids by the mRNA and a ribosome bonding with the help of tRNA.