Unit 3: LC #3/Culminating Event Flashcards
(52 cards)
How is DNA structured?
DNA has two individual strands which bind to each other through base pairs (A - T, G - C), creating a double helix shape
How are Chromosomes structured?
Each Chromosome is made up of tightly coiled (supercoiled) DNA strands, creating and supporting an “X” like shape
How is mRNA structured?
mRNA has one individual strand which holds 4 bases (A, U, G, C), creating a single helix shape
What are Nucleotides? How are they structured?
Nucleotides are the monomers of Nucleic Acid who’s bases make up Amino Acid sequences
- 1 Sugar Molecule
- 1 Phosphate Group
- 1 Nitrogenous Base
What are Genes?
A distinct pattern or sequence of nucleotide bases within a chromosome
What are the purpose(s) of Genes?
The specialized pattern of Genes determine the traits of the organism they reside in
What is the difference between the structure of DNA and mRNA?
While DNA has pairing base pairs to make a double helix shape, mRNA only has base pairs on one strand, making a single helix shape
What is the function of mRNA?
It carries messages from the DNA to active sites of the body in order to tell it how to make proteins, since original DNA molecules must stay within nuclei. (This is called protein synthesis)
What is Protein Synthesis?
The processes in which cells (being instructed by DNA/RNA) make protein for the body.
What are the steps of Protein Synthesis and where do they occur?
- Transcription - A strand of DNA being copied into mRNA for the message to be carried (it occurs in the Nucleus in Eukaryotes, and the Cytoplasm in Prokaryotes)
- Translation - mRNA using the DNA’s genetic information to instruct cells how to link Amino Acids and create Protein (It occurs in the Cytoplasm and Rough E.R)
In Translation, how are Nitrogenous Bases read?
Being packaged in Codons, Nitrogenous Bases are read in triplets, 3 at a time before the next and in 3 stations
What happens after all Nitrogenous Bases are read and turned into Amino Acids? (Protein Synthesis)
The Amino Acids formed from Translation eventually fold into shape atop one another to make a globular ball looking shape known as a Protein
How does the codon reading begin in Translation?
The site of production must first read the codon instructing it to start reading, which is AUG, or “Met”
How does the codon reading stop in Translation?
The site of protein production stops reading once it scans one of three codons instruction it to stop reading, which are UAA, UAG, and UGA, all decoding to “Stop”
What is the overall relationship between DNA, Proteins, and Functions of Life?
DNA is responsible for providing genetic code in order to create Proteins, which in turn give the bearer of these Proteins traits, which determine their life functions
How many Genes are present in a Chromosome?
Hundreds to thousands of Genes can be within a Chromosome
Where do Chromosomes come from, and how many are there?
Half of your Chromosomes come your birth mother (23), and half from your father (23), making 46 total chromosomes in a human
What is DNA Replication?
The process in which DNA makes an identical copy of itself through/during cell division
What are the steps of DNA Replication, and what happens in them?
- Initiation - DNA helicase unzips it into two, exposing half of it’s bases and getting ready for pairing
- Elongation - Nucleotides searching for matching bases to align and bond with, using DNA polymerase and primase
- Termination - The completion of DNA Replication after Okazaki Fragments are bonded by DNA ligase, resulting in two remaining DNA molecules ready for work
What are the 4 Enzymes involved in DNA replication, and what do they do?
- DNA Helicase - “Unzipping Enzyme”, it unzips the DNA
- DNA Polymerase - “The Builder” Builds new DNA strand after Helicase unzips
- DNA Primase - “The Initializer”, Indicates and marks where DNA Polymerase needs to go for building
- DNA Ligase - “The Gluer” - Glues DNA fragments together after being built, in order to have a fully-functioning double helix DNA strand
Which steps of DNA Replication involve which Enzymes?
- Initiation - (Helicase) unzips through DNA strand at point of origin, then different parts are marked by (Primase)
- Elongation - After seeing marked points done by (Primase), (DNA Polymerase) comes in and builds up a new strand step-by-step at marked locations
- Termination - (Ligase) comes in and glues Okazaki Fragments together at Primer locations, which eventually form an entirely new DNA molecules
What are Okazaki Fragments?
(Also known as Lagging Strands), Okazaki Fragments are short sequences of DNA nucleotide strands which need to be linked and glued by DNA Ligase in order for the completion of a new DNA Molecule. This is because they can only be read from their 5’ end to their 3’ end, making polymerase go back and forth
What are Leading and Lagging strands in DNA replication?
- Leading Strand - Strand(s) of DNA that are synthesized by continuously adding nucleotides to the 3’ end
- Lagging Strand - Strand(s) of DNA that are synthesized by adding nucleotides to the 5’ end in portions
PRACTICE! What is the mRNA strand version of this DNA sequence? (NO NOTES!)
AAA-CGT-ACG-CCC-AGT
UUU-GCA-UGC-GGG-UCA
(If you can, do it over with the paper to find out the amino acid sequence!)