- Shuffle
Toggle OnToggle Off
- Alphabetize
Toggle OnToggle Off
- Front First
Toggle OnToggle Off
- Both Sides
Toggle OnToggle Off
Front
How to study your flashcards.
Right/Left arrow keys: Navigate between flashcards.right arrow keyleft arrow key
Up/Down arrow keys: Flip the card between the front and back.down keyup key
H key: Show hint (3rd side).h key
PLAY BUTTON
PLAY BUTTON
63 Cards in this Set
- Front
- Back
|
What are neucleotides?
|
monomers of more complex nucleic acids
|
|
high energy phosphate carriers are an example of ____ nucleotides
|
single nucleotides- includes ATP , CTP, UTP, and GTP
|
|
electron carriers are an example of _____ nucleotides
|
dinucleotides (FAD, NAD, and NADP)
|
|
What are the 3 basic structural components of a neucleotide?
|
-a 5 carbon (pentose) sugar: ribose (RNA, ATP, FAD, NADP, etc) or deoxyribose (DNA)
- a nitrogenous base (purine or pyrimidine) - phosphate: 1 (MP) 2(DP) or 3 (TP) |
|
how is a nucleotide named?(acronym)
|
the first letter of the base plus the number of phosphates
ex: Adenine withe one phosphate= AMP |
|
what is a purine?
|
a 5 membered C/N ring fused into 5 members-
ex: Adenine (A) and Guanine (G) |
|
what is a pyrimidine?
|
a 6 membered C/N ring that serves as a nitrogenous base for nucleotides
ex: Cytosine (C) Uracil (U), and thymine (T) |
|
When is it appropriate to used GTP instead of ATP?
|
in protein shape changes with G proteins or other reactions triggered by specific receptors
|
|
What is the positional nomenclature of a nucleotide?
|
- the 1' carbon on the sugar has the purine/pyrimidine attached
- the phosphate group is attached to the 5' |
|
What structural component of a neucleotide is used to react with an adjacent molecule in the addition of neucleotides to an RNA/DNA chain?
|
hydroxyl group on the 3' carbon of the pentose (ribsoe or dexoyribose)
|
|
how are nucleotides lined into linear chains?
|
covalent bonds (modified dehydration) of the 3' carbon on one sugar to the phosphate on the 5' end of another
|
|
What part of a DNA/RNA chain will be reacted upon by polymerase enzymes for synthesis?
|
the 3' free end
|
|
what part of an RNA chain can be acted upon by mRNA to initiate translation?
|
the phosphate on the 5' free end
|
|
How does Adenine pair with Thymine/Uracil?
|
formation of 2 H bonds
|
|
how does Guanine bond with cytosine?
|
formation of 3 H bonds
|
|
What are the 3 functions of nucleotides within a cell?
|
-triphosphates carry energy from energy generating reactions to energy-requiring reactions
- serve as monomers for the synthesis of DNA/RNA - can be modified to use as a chemical signal within the cell (ex: cAMP) |
|
when will RNA be double stranded?
|
in some bacteria- in normal mammalian cells, RNA is single stranded with a few hairpin loops
|
|
what is mRNA?
|
messenger RNA- codes for the amino acid sequence (primary structure) of polypeptide chains in proteins
|
|
what is tRNA?
|
transfer RNA- carries the amino acids (as aminoacyl groups attached to tRNA) into protein sequences. TPs are used to hold the aminoacyl and form the peptide bond to add it to the chain
|
|
what is rRNA?
|
ribosomal RNA- form the structural framefork of ribosomal subunits
|
|
What are ribnucleoproteins?
|
RNPs- particles containing RNA molecules involved in RNA/protein processing. MAy involve the removal on introns from eukaryotes
|
|
When is DNA single stranded?
|
only briefly during aspects of replication and in some viruses- normal mammalian DNA is double stranded
|
|
why can the 2 chains of DNA be separated without breaking the strands?
|
the 2 chains are bonded together between the nitrogen bases (A/T, G/C) with hydrogen bonds, which are much weaker than the covalent bonds holding the neucleotides together within each chain
|
|
what implications does the double stranded nature of DNA have in terms of damage repair?
|
most damages can be repaired, provided the damage is not in the same place on both strands
|
|
what is a point mutation?
|
a change in the sequence of the deoxyribonucleotides in DNA
|
|
What is transcription?
|
RNA synthesis- the deoxyriboneucleotide sequence in DNA is read at a gene and used as a template the riboucleotide sequence in mRNA
|
|
what is a gene?
|
a specific region of DNA that codes fora protein
|
|
what is translation?
|
protein synthesis- certain regions of mRNA code for proteins
a 3 base codon on mRNA aligns with a 3 neucleotide anticodon on tRNA to allow the aminoacyl (Amino acid) to be added to the protein being synthesized |
|
what is the basic structure of a protein?
|
one of 20 amino acids covalently bonded to a carbon atom (alpha carbon), which is also attached to a carboxyl group
|
|
how do the 20 amino acids differ?
|
they have different side chains
|
|
what is the initiation codon for protein synthesis?
|
the methonine amino acid- most proteins must be later modified to remove this from the amino-terminal end
|
|
what must happen to many proteins after animal acid synthesis to become functional?
|
the addition of prosthetic groups (heme groups, etc), folding, removal of a methonine, possible kinase-catalyzed phosphorylation
|
|
what are signal/regulatory proteins?
|
proteins that respond to changes within a cell by changing their interactions with critical components (DNA, etc) to alter the function
|
|
what is the number one method of genetic regulation?
|
transcriptional (RNA synthesis) regulations
|
|
what enzyme catalyzes DNA replication?
|
DNA polymerase III
|
|
what provides the energy for DNA replication?
|
hydrolysis of 2 of the 3 phosphates attached to the deoxyriboneucleotide being added to the DNA strand
|
|
what is the directionality of DNA replication?
|
the DNA polymerase can only read the single template strand in the 3'-->5' direction and can only create a complimentary strand in the 5'-->3' position. Neucleotides can only be added to the 3' end
|
|
what is the function of DNA polymerase I and II?
|
DNA repair
|
|
what initiates DNA replication?
|
unclear, but the presence of an RNA primer (made by DNA primase) seems to kick the whole thing into motion
|
|
what is the replisome/replication complex?
|
the 6+ enzymes needed for DNA replication to occur: helicase, Polymerase III, Single strand DNA binding protein, DNA primase, lagging strand DNA polymerase III, DNA repair complex, and DNA ligase
|
|
what is DNA helicase?
|
the enzyme responsible for separating the 2 strands of DNA fo each can serve as the template of a new strand
|
|
what are okazaki fragments?
|
the short "chunks" of complementary strand created using the lagging (5' end) of DNA as a template
|
|
what is single strand DNA binding protein?
|
the protein that binds to and protects the exposed single strand regions on the lagging strand of DNA
|
|
what is DNA primase?
|
the enzyme that creates an RNA primer roughly ten neucleotides long to initiate replication.
|
|
what is lagging strand polymerase?
|
polymerase that acts upon the 3' end of the lagging strand until it hits the 5' end of the next RNA primer. It then "jumps" the 10ish neucleotides to rejoin at the other end of the primer and continue replication
|
|
what is the DNA repaircomplex?
|
DNA polymerase 1- it removed the riboneucleotides of the RNA primers and replaces them with the deoxyriboneucleotides
|
|
what is DNA ligase?
|
the enzyme that seals the free ends of 2 adjacent strands of DNA to form one long continuous strand
|
|
what are the different types of polymerase found in DNA replication specific to eukaryotes?
|
alpha polymerase (leading strand), delta polymerase, (lagging strand, and gamma polymerase (chromosome replication)
|
|
what is the function of a topoisomerase?
|
it prevents excessive tangling/twisting of DNA
Type1- clips on to allow untwisting Tye 2- cut the DNA to allow an interlocking strand pass through |
|
when are pyrimidine dimers created? How are they repaired?
|
UV rays- they're repaired by photoreactivation
visible light energy is used to remove the covalent bonds formed by UV- the gene responsible for this is not present in humans |
|
what is a glycosylase enzyme?
|
an enzyme responsible for base excision repair to remove a single damaged base from a neucleotide
(Base excision repair) |
|
where is the DNa located in prokaryotic cells?
|
in the cytoplasm
|
|
what is an operon?
|
a cluster of structural genes controlled by a single promoter
|
|
what is a promoter?
|
a binding site for RNA polymerase to initiate RNA synthesis
|
|
What is a sigma factor?
|
a protein that binds to RNA polymerase just upstream of the start point to initiate RNA synthesis- each sigma factor recognizes a different promoter sequence
|
|
what is an activator protein?
|
a control system for transcription- many promoters don't bind the RNA polymerase/sigma factor unless the activator protein is present
|
|
what is a repressor protein?
|
a transcription control system- many operons have a protein binding sequence (operator sequence) just downstream that can "block" transcription if the repressor protein is there
|
|
what kind of bond is found between neucleotides in RNA?
|
phosphodiester bond
|
|
what happens in transcription when the RNA chain is about 10 neucleotides in length?
|
the sigma factor pops off and the enzyme is more compact. Elongation factors may bind to the RNA polymerase
|
|
what is a rho-independent termination site?
|
a site triggering the end of transcription in which a guanine and cytosine hairpin loop is created next to a uridine-rich stretch
|
|
what is a rho-dependent termination site?
|
a site for the termination of trancription requiring terminating factor called rho for efficient conclusion
|
|
what is the function of riboneucleases?
|
they cut large rRNA down into functional RNA
|
|
What post-translation modifications must occur to RNA?
|
mRNA- none
rRNA- must be cut into smaller functional RNA tRNA- clusters must be cut, neucleotides must be modified to allow the anticodon to bond |
