AP Biology: Transcription & Translation Flashcards
chapter 14
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| 9352842555 | Central dogma of medicine | sequence of information is DNA → RNA → proteins | 0 | |
| 9352842556 | RNA | single stranded, ribose is the sugar, nitrogenous bases=A,U,C,G | 1 | |
| 9352842557 | DNA | double stranded, deoxyribose is the sugar, nitrogenous bases=A,T,C,G | 2 | |
| 9352842558 | Prokaryotic transcription & translation | all in cytoplasm (no nucleus); mRNA made directly into protein (no splicing); transcription and translation can occur at same time on same strand |  | 3 |
| 9352842559 | Eukaryotic transcription & translation | has nucleus; original mRNA molecule modified and sent to ribosomes for translation |  | 4 |
| 9352842560 | pre-mRNA | newly transcribed and non-edited mRNA | 5 | |
| 9352842561 | Three main types of RNA | messenger RNA (mRNA), transfer RNA (tRNA), & ribosomal RNA (rRNA); all have different structures/functions | 6 | |
| 9352842562 | Messenger RNA | single stranded; created during transcription using DNA code | 7 | |
| 9352842563 | Transfer RNA | cloverleaf shaped molecule; "reads" mRNA code during translation; each tRNA carries a specific amino acid and "reads" a specific mRNA sequence; has lots of G & C nucleotides b/c they're stronger (3 bonds, not 2) | 8 | |
| 9352842564 | Ribosomal RNA | globular molecule; along with proteins, makes up ribosomes; no specific role in translation/transcription; structural rather than informational | 9 | |
| 9352842565 | snRNA | small nuclear RNA; part of spliceosome; structural and catalytic roles | 10 | |
| 9352842566 | srpRNA | signal recognition particle that binds to signal peptides | 11 | |
| 9352842567 | RNAi | interference RNA; a regulatory molecule | 12 | |
| 9352842568 | miRNA/siRNA | micro/small interfering RNA; bind to mRNA or DNA to block it, regulate gene expression, or cut it up | 13 | |
| 9352842569 | Ribozyme | RNA that functions as an enzyme (snRNP) and self-edit/splice out own introns | 14 | |
| 9352842570 | Location of transcription | nucleus (for eukaryotes) | 15 | |
| 9352842571 | 3 steps of transcription | initiation, elongation, and termination | 16 | |
| 9352842572 | Initiation step of transcription | RNA polymerase binds to promoter region of DNA and separates strands, moving in 5' → 3' direction (does not need primer) | 17 | |
| 9352842573 | Elongation step of transcription | RNA chain grows in 5' → 3' direction as free nucleotides pair with nucleotides on template strand; non-coding strand reforms double helix | 18 | |
| 9352842574 | Termination step of transcription | transcription proceeds until reaches terminator site on DNA; RNA molecule then released | 19 | |
| 9352842575 | Additions to pre-mRNA during processing | for protection GTP "cap" added to 5' end and polyA "tail" added to 3' end | 20 | |
| 9352842576 | Intron | non-coding DNA segment; removed by snRNP before mRNA travels to ribosome | 21 | |
| 9352842577 | Exon | coding DNA segment that determines traits of organism (codes for proteins) | 22 | |
| 9352842578 | snRNP | enzymes made of proteins and RNA; part of spliceosome | 23 | |
| 9352842579 | UTR | untranslatable sequence at each end of mRNA | 24 | |
| 9352842580 | Benefit of introns | allows alternative splicing (introns and exons can vary), which allows for many combinations of genes | 25 | |
| 9352842581 | Useful characteristics of mRNA | single-stranded so can exit nuclear pores; has triplets (groups of 3 nucleotides) called "codons" that are read by tRNA triplets called "anticodons" via complementary base pairing | 26 | |
| 9352842582 | Useful characteristics of tRNA | cloverleaf structure; each tRNA attaches to different amino acid; anticodon matches with mRNA's codon to "read" and translate it into amino acid | 27 | |
| 9352842583 | Ribosome structure | made of rRNA and proteins; large and small subunits join to form functional ribosome when mRNA present | 28 | |
| 9352842584 | rRNA production | made in nucleolus, assembled with proteins from cytoplasm to make ribosomes | 29 | |
| 9352842585 | 3 binding sites for trNA in ribosome | A (aminoacyl-tRNA) site, P (peptidyl-tRNA) site, and E (exit) site |  | 30 |
| 9352842586 | 3 steps of translation | initiation, elongation and termination (same as transcription) | 31 | |
| 9352842587 | Initiation step of translation | small ribosomal subunit attaches to 5' end of mRNA ('start' codon - AUG); tRNA carries 1st amino acid (Met) to mRNA; large ribosomal subunit attaches to mRNA | 32 | |
| 9352842588 | Elongation step of translation | ribosome moves along mRNA and matches anticodons with codons; tRNA attaches to mRNA in A site; tRNA moves to P site; new amino acid moves to A site; polypeptide bond forms between amino acids; tRNA in P site releases amino acid and enters E site then exits | 33 | |
| 9352842589 | Termination step of translation | occurs when ribosome encounters 'stop' codon; ribosome subunits detach, releasing mRNA and polypeptide (mRNA can be "re-read") | 34 | |
| 9352842590 | Polysomes | strings of ribosomes that can work on same mRNA at same time to increase efficiency of translation |  | 35 |
| 9352842591 | Redundancy in genetic code | 64 codons code from 20 amino acids (accounts for wobble) | 36 | |
| 9352842592 | Wobble | codons for the same amino acid often differ in 3rd base | 37 | |
| 9352842593 | Post-translational modification | changes that happen to polypeptide after translation in order to make fully folded protein (example: chaperonins); correct folding is very important! (misfolded proteins causes many diseases, like Mad Cow) | 38 | |
| 9352842594 | Chaperonins | barrel shaped proteins molecules that help wrap protein into 3D shape | 39 | |
| 9352842595 | Types of post-translational modifications | molecular groups added (sugars, lipids, phosphates, etc.); and/or amino acid segments removed | 40 | |
| 9352842596 | Mutagens | environmental factors that cause mutations (example: radiation & cigarette smoke) | 41 | |
| 9352842597 | Carcinogen | mutagen that causes change in genes that regulate cell cycle/division | 42 | |
| 9352842598 | 2 main types of mutations | point mutation & frameshift mutation | 43 | |
| 9352842599 | Point mutation | change in one base pair of a gene (substitution: replace one base with another) | 44 | |
| 9352842600 | 3 types/effects of point mutations | silent, missense, & nonsense | 45 | |
| 9352842601 | Silent mutation | changes one base, but codes for same amino acid | 46 | |
| 9352842602 | Missense mutation | change in one base codes for another amino acid (example: sickle cell disease) | 47 | |
| 9352842603 | Nonsense mutation | change in one base codes for a stop codon (makes nonfunctional protein that is terminated early) | 48 | |
| 9352842604 | Frameshift mutation | mutation affects all nucleotides/codon groupings farther along DNA/RNA code | 49 | |
| 9352842605 | 2 types of frameshift mutations | insertion and deletion | 50 | |
| 9352842606 | Insertion mutation | adding extra nucleotides; causes frameshift unless multiple of 3 is added | 51 | |
| 9352842607 | Deletion mutation | removing nucleotides; causes frameshift unless multiple of 3 is removed | 52 |