Biology Flashcards: Describe Translation And Protein Assembly

What this deck covers

This deck focuses on Describe Translation And Protein Assembly, giving you a quick way to review the definitions, rules, and examples that matter most for Biology.

How to use these flashcards

Work through these flashcards in short sessions. Try to answer each prompt before flipping the card, then revisit any cards you miss until the explanation feels automatic.

Flashcard 1: What is wobble base pairing?

Answer: Flexible pairing at the third codon position allowing one tRNA to read multiple codons. Explains how fewer tRNAs can read all 61 codons.

Flashcard 2: Identify the stop codon among these options: AUG, UGA, UGG.

Answer: UGA. UGA is one of three universal stop codons.

Flashcard 3: Which option is the correct direction for ribosome movement: 3'\to^5' or 5'\to^3'?

Answer: 5'\to^3'. Ribosome reads mRNA template in this standard direction.

Flashcard 4: Identify the correct anticodon for the mRNA codon $5'\text{-GGC-}3'$ (write $3'\text{-}...\text{-}5'$).

Answer: $3'\text{-CCG-}5'$. G pairs with C in complementary base pairing.

Flashcard 5: Identify the correct anticodon for the mRNA codon $5'\text{-UUU-}3'$ (write $3'\text{-}...\text{-}5'$).

Answer: $3'\text{-AAA-}5'$. U pairs with A following standard base pairing rules.

Flashcard 6: What is translation in gene expression?

Answer: Protein synthesis from an mRNA template at a ribosome. Converts mRNA genetic code into functional protein sequences.

Flashcard 7: What are the three stop codons in mRNA?

Answer: UAA, UAG, UGA. Three nonsense codons that terminate protein synthesis.

Flashcard 8: Identify the stop codon among these options: AUG, UGA, UGG.

Answer: UGA. UGA is one of three universal stop codons.

Flashcard 9: Identify the start codon among these options: UAA, AUG, UAG.

Answer: AUG. AUG is the universal initiation codon for protein synthesis.

Flashcard 10: Which option is the correct direction of polypeptide growth: C→N or N→C?

Answer: N→C. Amino acids add to carboxyl end of growing chain.

Flashcard 11: Identify the correct statement: Stop codons code amino acids, or stop codons recruit release factors.

Answer: Stop codons recruit release factors. Stop codons signal termination, not amino acid incorporation.

Flashcard 12: Which option correctly describes tRNA charging: ribosome attaches amino acids, or aminoacyl-tRNA synthetase attaches amino acids?

Answer: Aminoacyl-tRNA synthetase attaches amino acids. Specific enzymes ensure accuracy in amino acid attachment.

Flashcard 13: Identify the correct anticodon for the mRNA codon $5'\text{-AUG-}3'$ (write $3'\text{-}...\text{-}5'$).

Answer: $3'\text{-UAC-}5'$. Anticodons pair with codons in antiparallel, complementary fashion.

Flashcard 14: What is a codon chart used for?

Answer: To determine the amino acid specified by an mRNA codon. Reference tool that decodes mRNA sequences into amino acids.

Flashcard 15: What is the role of the signal recognition particle (SRP)?

Answer: Binds signal peptide and directs ribosome to the rough ER. Recognizes signal sequences and guides ribosome to ER.

Flashcard 16: What is a signal peptide in protein targeting?

Answer: An N-terminal amino acid sequence that directs a protein to a destination. Molecular zip code that directs protein to correct location.

Flashcard 17: What type of proteins are typically made on free ribosomes?

Answer: Proteins that function in the cytosol or certain organelles. Lack targeting signals so remain in cytoplasmic location.

Flashcard 18: What type of proteins are typically made on rough ER-bound ribosomes?

Answer: Secreted, membrane, or lysosomal proteins. Signal sequences direct these proteins to ER during synthesis.

Flashcard 19: Which cellular location is typical for translation in prokaryotes?

Answer: Cytosol (often coupled to transcription). No nuclear separation allows immediate translation of mRNA.

Flashcard 20: What is the maximum number of codons in an mRNA region that is $90$ nucleotides long?

Answer: $30$ codons. Three nucleotides form one codon; $90 ÷ 3 = 30$.

Flashcard 21: What is the maximum number of amino acids in a peptide translated from an mRNA of $300$ nucleotides (ignore UTRs)?

Answer: $100$ amino acids. Each codon specifies one amino acid; $300 ÷ 3 = 100$.

Flashcard 22: What is the key difference between free ribosomes and rough ER-bound ribosomes?

Answer: They are identical; location determines protein destination. Ribosome location, not structure, determines protein destination.

Flashcard 23: Which ribosomal site first binds the initiator tRNA during initiation?

Answer: P site. Initial binding site where protein synthesis begins.

Flashcard 24: What are the three ribosomal tRNA binding sites?

Answer: A site, P site, E site. Sequential sites where tRNAs move during translation cycle.

Flashcard 25: What happens at the A site of the ribosome?

Answer: Incoming aminoacyl-tRNA binds the next codon. Entry point for new amino acids during protein elongation.

Flashcard 26: What happens at the P site of the ribosome?

Answer: tRNA holds the growing polypeptide chain. Central position where the growing protein chain is held.

Flashcard 27: What happens at the E site of the ribosome?

Answer: Deacylated tRNA exits the ribosome. Final position before tRNA leaves the ribosome completely.

Flashcard 28: What bond links amino acids together during translation?

Answer: Peptide bond. Covalent bond that creates the protein backbone structure.

Flashcard 29: What ribosomal activity catalyzes peptide bond formation?

Answer: Peptidyl transferase activity of rRNA (a ribozyme). Ribosomal RNA acts as enzyme to form protein bonds.

Flashcard 30: In what direction does the ribosome move along the mRNA?

Answer: From $5'$ to $3'$. Directional movement ensures proper codon reading sequence.