Decoding Info DNA-Origins Of life , FOR TEST Flashcards
Name some fictions of proteins
- enzymes
- structural purposes
- determine the traits that we have
Proteins are not ______ _______ from DNA.
Built directly
RNA
Ribonucleic acid-nucleic acid made of nucleotides
In what three ways does RNA differ from DNA?
- RNA consists of a single strand of nucleotides, not two strands
- RNA nucleotides contain the 5-carbon sugar ribose, not deoxyribose. Ribose contains one more oxygen than deoxyribose.
- RNA nucleotides contain A, G, and C like DNA, but instead of Thymine, RNA contains uracil, which is complementary to at adenine
The instructions in DNA code for the _______________________________________.
Construction of proteins
What’s Transcription and where does it take place?
The process by which a gene’s instructions for making proteins are transferred to an RNA molecule. Transcription occurs in the nucleus where the DNA is located.
What is the first step in transcription?
RNA polymerase, an enzyme that binds complementary RNA nucleotides during transcription, binds to a special start sequence of DNA.
What is the seconds step of transcription?
RNA polymerase unwinds and separates the two strands of the double helix.
What is the third step in transcription?
RNA polymerase adds and links complementary RNA nucleotides as it reads the DNA.
(Transcription follows the base-pairing rules for DNA replication except that in RNA, uracil (instead of thymine) pairs with adenine)
What is the fourth step in transcription?
Transcription proceeds until RNA polymerase reaches a stop sequence of bases that marks the end of a gene.
What is the fifth step in transcription?
After transcription has completed, the two strands of DNA close up, reforming the double helix and the RNA strand separates from the DNA.
Transcription is like DNA replication, only that ______________________________________.
One strand of RNA is produced instead of two strands of DNA.
Also in DNA replication, both strands of DNA are used as templates, but in transcription, ________.
Only one strand is used.
Different types of __________ can be formed by transcription.
Nucleotides
Messenger RNA (mRNA) -At the \_\_\_\_\_\_\_\_\_\_\_, the instructions are "read" which code for \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_. Many \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ join together to make a protein. ~the RNA instructions are written as \_\_\_\_\_\_\_\_\_\_\_
Carries the instructions for building a protein from the DNA gene to the ribosome.
-Ribosomes, specific amino acids, amino acids.
~codons
Codons
A series of three nitrogenous bases on the mRNA
The Genetic code
Shows all 64 possible codons and the amino acids that they code for.
What’s Translation? Where does it take place? What’s two types of RNA help this process?
Using different types of RNA molecules to read the instructions on mRNA and put together the amino acids that makeup the protein.
Takes place in the cytoplasm at the ribosomes.
tRNA and rRNA
What’s tRNA
Transfer RNA:
Folded molecules that carry a specific amino acid on one end
Other end has an anticodon
Anticodon
Three-base sequence that is complementary to an mRNA codon.
What’s rRNA
Ribosomal RNA:
Helps make up ribosomes
Translation occurs at the ribosomes
What’s the first step of translation?
mRNA leaves the nucleus and enters the cytoplasm. There, it attaches to a ribosome.
What’s the second step in translation?
The ribosome “reads” the codon. A tRNA molecule with the complementary anticodon arrives and binds to the codon. The tRNA is also carrying its specific amino acid.
What’s the third step in translation?
The tRNA molecule then separates from the amino acid, and leaves the ribosome.
What’s the fourth step in translation?
The ribosome then moves along to the next codon and a new tRNA molecule takes its place on the mRNA strand. The new amino acid brought in joins the other ones (by forming a peptide bond)
What the fifth step in translation?
Amino acids are added to the growing chain, called a polypeptide chain until the ribosome reaches a stop codon.
What’s the sixth step in translation?
The polypeptide chain is then let go, and it folds into a protein molecule.
Mutation
A change in the DNA of a gene.
Mutations can be passed on to offspring through the ______________________________
Gametes of an affected individual.
Mutations can occur in the body cells of an individual but these will only _____________________________.
Affect the individual in which they occur.
Gene rearrangements
Example
Mutations that move an entire gene to a new location.
Translocation
What’s translocation?
The movement of part of a chromosome to a different location. Translocation may happen within the same chromosome or between different chromosomes.
Gene alterations
Mutations that change a gene itself
Substitution mutation and what it may result in.
A nucleotide with a different nitrogenous base replaces the original nucleotide.
Missense mutation, silent mutation
Missense mutation
Results in a change in a single amino acid in the inal polypeptide
Silent mutation
The new codon codes for the same amino acid so no change occurs.
Insertion
A piece of DNA is inserted into a gene.