DNA/RNA Review Answers Flashcards
What does DNA stand for?
Deoxyribonucleic acid
What is DNA?
There is only one type of DNA. DNA is an organism’s genetic material
What are the two names for the shape of DNA?
Twisted zipper or double helix
Who is credited with discovering the shape of DNA?
James Watson and Francis Crick discovered the shape of DNA, that it is a helix
Who is credited for the x-rays of DNA?
Rosalind Franklin and Maurice Wilkins
Who is credited with discovering the chemicals of DNA?
Erwin Chargaff
Explain the parts that make up a nucleotide
Nitrogen base, sugar, and a phosphate group
What is an example of a nucleotide
phosphate, deoxyribose sugar, and nitrogen base adenine
What are the four nitrogen bases in DNA?
adenine (A), thymine (T), cytosine (C), and guanine (G)
How do the four nitrogen bases in DNA pair together?
A bond with T & C and G always bond
What holds the two nitrogen bases together?
Hydrogen bonds
Explain replication
- Replication is the process of copying a DNA molecule to make another DNA molecule. 2. This replication is semi-conservative because it produces two identical strands of DNA, each having one OLD strand in one NEW strand. 3. Replication of DNA occurs before transcription and translation.
Define RNA
Ribo nucleic acid
What is RNA?
It is a type of nucleic acid that carries the code (this code is coming originally from DNA) for making proteins from the nucleus to the cytoplasm.
How many types of RNA are there?
Three
Explain the similarities and differences between DNA and RNA
- They are both nucleic acids 2. There is only one type of DNA but there are three types of RNA 3. DNA is a double strand and RNA is a single strand. 4. DNA can’t leave the nucleus it is too big but RNA can fit out of the nucleus because it is only a single strand 5. DNA has deoxyribose sugar (D to D) and RNA has ribose sugar (R to R) 6. DNA and RNA both have the nitrogen bases adenine guanine and cytosine but DNA has the fourth nitrogen base as thymine and RNA has the fourth nitrogen base as uracil. You will not see uracil in a DNA strand and you will not see thymine in an RNA strand.
What is a gene and how is it related to DNA?
A gene is a section of DNA that has many nitrogen bases and codes for a protein that determines your traits
Your traits are determined by what?
Protein that is coded by a gene that is made up of DNA
What are the three types of RNA?
MRNA, rRNA, tRNA
What is mRNA?
Messenger RNA that transcribes the genetic code from DNA that can be read and used to make proteins. DNA is the originator of the message. MRNA carries the DNA genetic information from the nucleus to the cytoplasm of the cell. The order of the nitrogen bases and mRNA determines the order of the amino acids in a protein. 3 nitrogen bases on the mRNA form the code for 1 amino acid. Each series of three nitrogen bases on mRNA is called a codon
What is rRNA?
Ribosomal RNA is found in the cytoplasm of a cell where ribosomes are found. It helps form chemical bonds that attach one amino acid to the next. Remember amino acids are the building blocks of proteins.
What is tRNA?
Transfer RNA carries amino acids to the ribosome. It is also located in the cytoplasm and transfers amino acids to the ribosome that corresponds to each three-nucleotide codon of the rRNA. Once the amino acids reach the ribosome they are assembled into proteins. Protein has the original message of DNA.
What is a codon and what does it code for?
The series of three nitrogen bases on mRNA is the codon (secret code). The order of the three nitrogen bases determines the order of the amino acids in a protein. There are 64 codons, but only 20 amino acids
Define mutation
A mutation is a change in the nucleotide sequence of a gene. Most changes are corrected before replication occurs. Not all mutations are bad. Some are good, some are neutral and some are very bad.
Does a mutation always have a negative affect on an organism? Why or why not?
Not all mutations have negative affects. Some mutations don’t cause changes in proteins, so they don’t affect traits and they are neutral. Some mutations may cause a trait to change in a way that benefits the organism. Negative mutations occur when the mutation changes the proteins and cause the proteins to change to cause genetic disorders
What is and where does transcription occur?
Transcription occurs first and it occurs in the nucleus. Transcription is the process of making mRNA from DNA. DNA can’t get out of the nucleus, DNA never leaves the nucleus. Therefore it must pass on its original message to mRNA. MRNA nucleotides pair up with the DNA nucleotides. Completed mRNA is small and can get out of the nucleus through the nuclear pores. MRNA moves to the cytoplasm and finds the organelle ribosome. Translation occurs in ribosomes and ribosomes are found in the cytoplasm.
What is the complementary DNA strand to the following ATTCCAGC
TAAGGTCG
What is the complementary mRNA strand for the following TTGCATGGA
AACGUACCU
AACGUACCU What is the amino acid sequence? Remember three nitrogen bases from the mRNA is the sequence for one amino acid
AAC = asn, GUA= val, CCU = pro, therefore the sequence is asn val pro
What is and where does translation occur?
Translation is the process of making a protein from the RNA. Remember the original message is from the DNA and the message is carried by different types of RNA to create proteins. Amino acids are the building blocks to form proteins. Protein is the ultimate product of transcription/translation. Protein has the original message of DNA. It is the protein that tells the different cells their function.
How many codons are there? And how many amino acids are there?
64 codons and 20 amino acids
