Final Exam Review Flashcards
__________ hypothesis: Each gene is responsible for making one enzyme. It was expanded to include genes that produce proteins other than enzymes or to produce RNAs as final products.
One gene, one enzyme / one gene, one polypeptide
Genes _____ enzymes, because specific genetic defects results in specific enzymatic defects.
encode
Central Dogma refers to the flow of information from _____ to _____ to _____. However, sometimes information can flow from _____ back to _____.
DNA, RNA, proteins, RNA, DNA
What intracellular unit are proteins synthesized?
ribosomes
mRNA stands for _____ RNA or single stranded molecules of RNA. mRNA carries DNA from inside the _____ to _____.
messenger, nucleus, ribosomes
The process of using a DNA template to make an RNA molecule that has a base sequence complimentary to the DNA. DNA to RNA by RNA polymerase.
Transcription
The process of using info in mRNA to synthesize proteins. Information stored in mRNA is put into proteins by ribosomes.
Translation
How are DNA polymerase and RNA polymerase similar? How do they differ?
They use the DNA strand as a template to specify which complimentary nucleotide to add the the growing, newly synthesized strand. RNA polymerase does not require a primer.
(A) is the information carrier, (B) is the information storage, and (C) is the active cell machinery.
- Proteins
- mRNA
- DNA
A) mRNA
B) DNA
C) Proteins
_____ is determined by the sequence of bases in DNA while it’s _____ is a product of the proteins it produces.
Genotype, Phenotype
A group of three bases that specify an amino acid
A codon
1 base code specifies ___ amino acide, 2 base codes specify ___ amino acids, and three base codes specify ___ amino acids, even though there are only ____ amino acids.
4, 16, 64, 20
A sequence of codons is referred to as:
the reading frame
Name the start codon, it’s corresponding amino acid, and the three stop codons.
AUG (methionine), UAA, UAG, UGA
All but two amino acids are coded for by more than one codon. The code is _____.
Redundant.
A given codon never codes for more than one amino acid. The code is _____.
Unambiguous
The template strands includes _____ while the non-template strand includes _____.
Thymine, Uracil
When the ribosome locks onto the first codon the reading frame is established. The code is _____.
non-overlapping
Codons usually specify the same amino acids in all organisms. The code is _____.
Nearly universal
The first two bases in a codon are usually identical when several codons specify the same amino acid. The code is _____.
Conservative
A mutation that alters the sequence of one or a small number of base pairs.
Point mutation
Point mutations that change the identity of an amino acid in a protein.
Missence mutations
Mutations that shift the reading frame.
Frameshift mutations
Mutations that occur when a codon that specifies an amino acid is changed by mutation to an amino acid that specifies a stop codon, causing early termination of the polypeptide chain and results in a non-functional protein.
Nonsense mutations
Mutations are random changes in _____.
genotype
_____ mutations are neutral, _____ mutations can be beneficial, neutral, or deletrious, and _____ and _____ mutations are often or always deletrious.
silent, missence, frameshift, nonsense
_____ refers to having more than 2 of each chromosome, while _____ is the addition or deletion of individual chromosomes.
polyploidy, aneuploidy
When chromosomes form breaks, segments can detach. When those segments are flipped and rejoined to the same chromosome it is called chromosome _____. When those segments attach to a different chromosome it is called chromosome _____.
Inversion, translocation
Mutations producing polyploidy or aneuploidy don’t change _____ _____, but they do cause permanent change in an organisms DNA by altering the _____ of _____ of each sequence.
DNA sequence, number of copies
_____ contain sulfur and not phosphorus, while _____ contains phosphorus but not sulfur.
Proteins, DNA
Do viral genes consist of DNA, protein, or both?
DNA
_____ bonds form between stabilizing complimentary base pairs (A and T - C and G), and _____ interactions between bases in the double helix also stabilize DNA.
Hydrogen, hydrophobic
What is the basis of DNA replication?
Complimentary base pairing
Does DNA replicate by semiconservative replication, conservative replication, or dispersive replication?
semiconservative replication
Are polymerization reactions endergonic or exergonic?What about the formation of phosphodiester bonds?
Endergonic at first, but the formation of phosphodiester bonds in a DNA strand is exergonic.
DNA synthesis proceeds in the _____ direction.
5’S3’
What raises the potential energy of deoxyribonucleotid monomers?
Reactions that add 2 phosphate groups to form dNTPs.
Y shaped region where parental DNA synthesis is bidirectional and where active DNA synthesis occurs.
Replication Fork
Enzyme that breaks hydrogen bonds between base pairs in that location and opens up double helix causing two strands of DNA to separate at the replication fork.
DNA helicase
A protein that attaches separate strands of DNA during replication, preventing the reformation of a double helix.
(Single strand DNA-binding proteins) SSBPs
RNA strands a dozen nucleotides long that form complimentary base pairs with DNA template strands.
primers
_____ supply the 3’ hydoxyl end for DNA polymerase.
primers
An enzyme that synthesizes the short stretch of RNA and acts as a primer for DNA polymerase before DNA synthesis begins.
Primase
_____ and other _____ polymerase do not require a primer to begin synthesis. ____ does require a primer to begin synthesis.
Primase, RNA, DNA
What step proceeds the DNA ligase enzyme catalyzing the formation of phosphodiester bonds between adjacent okazaki fragments?
The RNA primer must be removed and replaced by DNA
What causes the DNA labelled in the pulse-chase study to become longer during the chase?
The action of DNA polymerase I followed by DNA ligase
What is a replisome?
It’s a macromolecular machine that copies DNA. Most enzymes join here (DNA polymerase, helicase, primase, etc.)
The very end of a eukaryotic chromosome is called a
telomere
The _____ strand synthesis results in a double stranded copy of the DNA molecule.
leading
_____ catalyzes the synthesis of DNA from the RNA template that it contains, adding DNA to the END of the chromosome to lengthen it and to stop it from shortening.
Telomerase
DNA is synthesized from the ___‘-OH of a single strand, and the leading strand moves in a ___’ S ___’ direction.
3, 5, 3
Telomerase is primarily found in human cells that produce _____.
Gametes
Chromosomes of somatic cells gradually shorten with _____ cell division and become smaller as an individual ages.
mitotic
DNA polymerase speeds along the DNA template and _____ bonding occurs between incoming deoxyribonucleotides and the ones on the template strand. The ability of DNA polymerase to _____ results in an error rate of 1 in a billion.
hydrogen, proofread
The enzyme that removes deoxyribonucleotides from the end of DNA strands.
exonuclease
DNA damage by uv light or chemicals causes a _____ to form between adjacent pyrimidine bases and a _____ to form in the DNA’s structure, leading to the stall of DNA _____ and replication.
bond, kink, polymerase
