Chapter 6 Flashcards
What is replication
DNA duplication
What is transcription
RNA is synthesized from DNA template. First step is gene expression and it can be regualted by transcription factors
What are transcription products
mRNA, tRNA, and rRNA
What is mRNA
Messenger RNA: encodes polypeptides
What is tRNA
Transfer RNA: plays role in protein synthesis
What is rRNA
Ribosomal RNA: makes up the ribosomes
What is translation
Inform in mRNA is used to build polypeptides on ribosomes, this can also be regulated
Describe a dsDNA strand
DNA strands are anti-parallel (5 to 3 is complement to 3 to 5), in a double helix and base pairing holds the two strands together.
In mRNA what is the codon do (triplet code)
In the mRNA, the codon (triplet code) is recognized by tRNA to translate a particular amino acid into the sequence.
Describe the ends of the amino acid sequence (protein). In what direction are protines synthesized by ribosomes
The protein strand begins with the N-terminus (-NH2) and ends with the C-terminus (-COOH). Proteins are synthesized from the N-terminus to C-terminus direction
What is the central dogma of molecular biology
DNA to RNA to Protein
How are genes transcribed in Eukaryotes
Each gene is transcribed individually. There are introns present and mRNA undergoes splicing
How are genes transcribed in Prokaryotes
Multiple genes are sometimes transcribed together, usually involved in the same pathway (operon), almost no introns or no RNA splicing
What is an operon
Operon are bacterial gene transcripts that contain more than one gene, encoding enzymes of a single biochemical pathway. Each gene on the mRNA will have its own start and stop codons to make separate proteins when it undergoes translation
What is the benefit of prokaryotes transcribing genes in the cytoplasm
Because it takes place in the cytoplasm, while the mRNA is being transcribed, ribosomes can attach to it and begin translation
What are the 3 components of nucleic acids
Sugar, Base, and Phosphate group
What are the possible sugars in nucleic acids
Deoxyribose and ribose
What are the possible bases in nucleic acids
Nitrogen bases: Cytosine, Thymine, Uracil, Adenine, and Guanine
What connects the sugars to one another
The phosphate, a phosphodiester bond
What are the complementary base pairs
A pairs with T/U and G pairs with C
What is on the 5’ and 3’ end of the DNA strand
5’ end has a phosphate group and 3’ end has a hydroxyl group
What is a genome
Entire complement of genes in cell or virus
What is a chromosome
Main genetic element in prokaryotes. Usually one circular chromosome per cell. They contain the essential “housekeeping genes”
What are housekeeping genes
They are essential genes that are needed for replicating DNA, transcribing genes, making ribosomes, all the fundamental metabolism needed for a cell to be alive