BIO Set #3 Ch. 5-6 & 11 Flashcards
DNA, PROTEIN SYNTHESIS, MITOSIS, MEIOSIS, REPRODUCTION, IMMUNE, and GENETICS
Identify the enzyme that replicates DNA (which direction does it work?)
DNA
The enzyme that replicates DNA is called DNA polymerase and it works in the 5’ to 3’ direction, meaning it adds new nucleotides to the 3’ end of the growing DNA strand.
What enzyme separates the DNA for replication and what bonds are broken
DNA
DNA helicase
Breaks the hydrogen bonds between the base pairs on the DNA strands, allowing them to separate and be copied
What stage of the cell cycle does DNA replication take place? Be specific:
DNA
DNA replication occurs during the Synthesis phase (S phase) of the cell cycle
What bonds are broken between complimentary stands of DNA?
DNA
Hydrogen Bonds
between the complementary base pairs:
(adenine with thymine, and cytosine with guanine).
ALWAYS. A -T and C - G
What enzyme bonds DNA fragments in the 3’ to 5’ direction?
DNA
DNA ligase
According to Watson and Crick, DNA replication is…
DNA
semi-conservative,
meaning that each new DNA molecule contains one strand from the original DNA molecule and one newly synthesized strand, with each original strand serving as a template for the new complementary strand (making copies)
Which enzyme reduces the stress during DNA replication?
DNA
topoisomerase
Explanation: Topoisomerase works by temporarily breaking and rejoining DNA strands, allowing the DNA to unwind and relieve the tension created during the unwinding process at the replication fork.
What enzymes are needed for DNA repair and/or mutation repair?
DNA
DNA polymerase (for resynthesis of the damaged region)
DNA ligase (to seal the repaired DNA strand)
DNA glycosylase
Enzyme repair
What is the difference between the leading strand vs. lagging strand?
DNA
Leading strand replicates continuously in the direction of the replication fork
Lagging strand replicates discontinuously in small fragments moving away from the replication fork
Lagging strand replicates discontinuously in small fragments called what?
DNA
Okazaki fragments
What is proofreading in reference to DNA replication? Which enzyme is involved?
DNA
DNA polymerase
DNA polymerases are the enzymes that build DNA in cells. During DNA replication (copying), most DNA polymerases can “check their work” with each base that they add. This process is called proofreading.
Which nitrogenous bases are Pyrimidines and which are Purines?
DNA
Pyrimidine bases are Cytosine, Thymine, and Uracil. (CUT)
Purine bases are Adenine and Guanine (AG)
What is and why is Primase needed?
DNA
Without primase, DNA replication cannot start.
DNA polymerase cannot start building a new DNA strand without a primer, making primase essential for the process of DNA replication.
Creates short RNA primers by binding to a single-stranded DNA template
What is a RNA primer and why is it needed?
DNA
They act as a template for DNA polymerase to begin building a new DNA strand. An RNA primer is a short segment of RNA that acts as a starting point for DNA synthesis during DNA replication.
Key points about RNA primers:
Function: They act as a template for DNA polymerase to begin building a new DNA strand.
Synthesis: An enzyme called primase creates the RNA primer.
Removal: Once the DNA strand is synthesized, the RNA primer is removed and replaced with DNA nucleotides.
If Cytosine is 15% - what are the other nitrogenous base concentrations?
DNA
If Cytosine is 15%, then Guanine will also be 15%, and both Adenine and Thymine will be 35% each.
Explanation:
Chargaff’s rule:
This principle states that in a DNA molecule, the amount of Cytosine always equals the amount of Guanine, and the amount of Adenine always equals the amount of Thymine.
Calculation:
Cytosine (C) = 15%
Guanine (G) = 15%
Therefore, Adenine (A) + Thymine (T) = 100% - (C + G) = 70%
Since A = T, then A = T = 35%
What is a mutation?
DNA
Is the source of variation of all things
What site on the ribosome does the 1st tRNA attach in protein synthesis?
Protein Synthesis
The first tRNA in protein synthesis attaches to the P SITE on the ribosomes,
this is specifically called the “peptidyl” site and is where the initiator tRNA binds to the start codon of the mRNA.
What are 3 similarities between RNA and DNA
Protein Synthesis
nucleotides, which consist of a sugar
phosphate group,
same nitrogenous bases (Adenine, Guanine, and Cytosine)
What are 3 differences between RNA and DNA?
Protein Synthesis
different sugars (ribose sugar)
Base is uracil instead of thymine
RNA is single stranded
DNA is double-stranded,
DNA contains deoxyribose, a
thymine which is found in DNA
What is the anticodon for the codon AUG?
Protein Synthesis
UAC
What kind of bond forms between the amino acids as the protein chain is forming?
Protein Synthesis
peptide bond
it’s a covalent bond formed between the amino group of one amino acid and the carboxyl group of the next amino acid, essentially linking them together to create a polypeptide chain
What enzyme makes RNA and which direction does it work?
Protein Synthesis
5’ to 3’ RNA polymerase bond
What is RNA processing and where does it happen?
Protein Synthesis
RNA processing is the modification of a newly formed RNA transcript, called pre-mRNA, to produce a functional messenger RNA (mRNA) molecule, and it primarily occurs in the nucleus of eukaryotic cells;
this involves removing non-coding regions (introns) and splicing together the coding regions (exons) of the transcript to create a mature mRNA ready for translation into protein.
Key points about RNA processing:
Location: Primarily happens in the nucleus of eukaryotic cells.
Process: Includes adding a 5’ cap to the leading end of the RNA, removing introns, splicing exons together, and adding a poly-A tail to the 3’ end.
Importance: RNA processing ensures that only the correct coding sequence is translated into protein.
What is transcription and where does it happen?
Protein Synthesis
Process of transcribing the DNA by RNA polymerase to make RNA. Takes place in the nucleus.
What is translation and where does it take place?
Protein Synthesis
Wherever there are Ribosomes
Translation takes place on ribosomes in the cell cytoplasm, where mRNA is read and translated into the string of amino acid chains that make up the synthesized protein.
How many codons are needed to build a protein that has 5 amino acids?
Protein Synthesis
5
The codon is located on the:
Protein Synthesis
mRNA
The anticodon is located on the:
Protein Synthesis
tRNA
Indicate the start codon:
Protein Synthesis
AUG
The first tRNA anticodon will always bond with its codon in which site on the ribosome?
Protein Synthesis
P site
How many anticodons are needed to build a protein that has 5 amino acids?
Protein Synthesis
5
A cell with 26 chromatids at the start of MITOSIS will produce cells with ___ chromosomes?
Mitosis
13
What are the anticodons for the stop codons?
Protein Synthesis
UAA, UAG, and UGA,
The stop codons are UAA, UAG, and UGA, and they do not code for any amino acids
What does Diploid and Haploid mean?
Mitosis
Haploid: One set of chromosomes (half chromosome)
Diploid: Two sets of chromosomes (full set chromosome