Final Exam Study (Fall '22) Flashcards
Differences in the shapes of DNA and RNA
DNA = double strand (double helix)
RNA = single strand
Base pairs of DNA and RNA and pairing rules
DNA = Guanine + Cytosine ; Adenine + Thymine
RNA = Guanine + Cytosine ; Adenine + URACIL
What is a nucleotide?
A nitrogen base, sugar, and phosphate.
Through what part of the nucleotides are the two strands of DNA held together?
Hydrogen bonds hold together nucleotides through the base pairs.
What make up the ‘rungs’ of DNA?
Base pairs
Name for RNA?
Ribonucleic Acid
What sugars does RNA contain?
Ribose sugars
Name for DNA?
Deoxyribonucleic Acid
What sugars does DNA contain?
Deoxyribose sugars
What occurs in replication and where does it occur?
DNA makes a copy of itself - occurs in the nucleus.
What are the results of replication?
Two new copies with an original strand on each (semi-conservative replication)
What occurs in transcription and where does it occur (four areas)?
An RNA copy is made of the DNA - starts in the nucleus, goes to the cytoplasm, then to the rough ER (endoplasmic reticulum), and to the ribosome lastly (for translation to start).
What occurs in translation (what is turned to what) and where does it occur?
RNA is used to make amino acids, which are made to polypeptides into proteins - it occurs in the cytoplasm in the ribosome
Where does translation begin (where on the strand)?
Starts at the start codon and stops at the stop codon
ENZYME: Helicase - what does it do and where?
‘unzips’ or splits the DNA along the hydrogen bonding
ENZYME: Primase - what does it do and where (on the strand)?
Generate primers that bind to the 3’ (three prime) end of the strand
ENZYME: Polymerase - what does it do?
Creates the new strand through elongation.
ENZYME: Other than replication, what other processes does polymerase participate in? (Two)
Repair and error-checking
Okazaki fragments - what are they, what made them, and where are they located?
Pieces of DNA added by polymerase to the lagging strand (between primers)
ENZYME: Ligase - what does it do?
joins or ‘glues’ the Okazaki fragments together
ENZYME: Topoisomerase - what is another name for it? What does it do, and for what purpose?
Gyrase - Unwinds and rewinds DNA strands to keep them from becoming supercoiled
What does mRNA stand for and what does it do in what stage of protein synthesis?
Messenger RNA - carries code from DNA to ribosomes in transcription.
What does tRNA stand for and what is its role?
Transfer RNA - brings the mRNA codon and corresponding amino acid together through tRNA’s anticodon.
What does rRNA stand for, what is its role, and where is it located?
Ribosomal RNA - located on the ribosome, it reads mRNA codons and matches them to tRNA codons
What is a codon?
The RNA three nucleotide sequence that codes for an amino acid
What is an anticodon?
The three nucleotide sequence found on tRNA that binds to the corresponding mRNA sequence (codon)
How many amino acids are there?
20
How many nucleotides (bases) are there?
4 (A, T, G, C) or (A, U, G, C)
How many possible codons (combinations of nucleotides) are there?
64
Watson and Crick won the Nobel Prize for what?
DNA structure
Describe concentrations in an isotonic condition (solution) and what happens to the cell and why
Concentration of solution and cell are the same - nothing happens to the cell because the solution and cell ‘go through’ each other