2.3.2 Protein synthesis

• RNA is double-stranded, whereas DNA is single-stranded.

  False
• Which nitrogenous base replaces thymine in RNA?

  Uracil
• mRNA carries the genetic code from DNA to the ribosomes
• Ribosomes are made up of rRNA and proteins.


  True
• What type of sugar is found in mRNA?

  Ribose
• Where does the process of translation occur in the cell?

  Ribosome
• Steps of the translation process

  1️⃣ mRNA binds to the ribosome

  2️⃣ tRNA molecules bind to complementary codons on mRNA

  3️⃣ Amino acids are linked to form a protein
• Steps in the process of translation

  1️⃣ The mRNA molecule binds to the ribosome.

  2️⃣ tRNA molecules bind to complementary codons on the mRNA.

  3️⃣ Amino acids are joined by peptide bonds.

  4️⃣ The ribosome moves along the mRNA.

  5️⃣ The complete polypeptide is released and folds.
• tRNA molecules carry specific amino acids
• The coordinated actions of mRNA, tRNA, and rRNA allow genetic information in DNA to be translated into functional proteins.


  True
• Uracil replaces thymine in RNA.
• What is the function of mRNA in protein synthesis?

  Carries genetic code
• If the DNA sequence is ATCGATTAC, what is the corresponding mRNA sequence?

  AUCGAUUAC
• Stages of translation and their key events

  1️⃣ Initiation: Ribosome binds to mRNA at start codon (AUG).

  2️⃣ Elongation: tRNA brings amino acids to form a polypeptide chain.

  3️⃣ Termination: Ribosome reaches a stop codon and releases the polypeptide.
• Match the feature of tRNA with its description:

  Structure ↔️ Single-stranded RNA folded into a cloverleaf shape

  Amino Acid Binding ↔️ Attaches to a specific amino acid based on its anticodon

  Codon Recognition ↔️ Anticodon complements a specific mRNA codon
• Ribosomes facilitate the attachment of tRNA to mRNA codons during translation.


  True
• In codon-anticodon matching, adenine pairs with uracil.
• What enzyme do ribosomes help catalyze in protein synthesis?

  Peptide bond formation
• Each mRNA codon is a three-nucleotide sequence that specifies a single amino acid.
• Match the mRNA base with its complementary tRNA base:

  Adenine ↔️ Uracil

  Guanine ↔️ Cytosine

  Uracil ↔️ Adenine
• Codon-anticodon matching ensures amino acids are added in the correct order during protein synthesis.


  True
• Which nitrogenous base is unique to RNA?

  Uracil
• Match the RNA type with its function:

  mRNA ↔️ Carries genetic code from DNA to ribosomes

  tRNA ↔️ Transports amino acids to ribosomes

  rRNA ↔️ Combines with proteins to form ribosomes
• During transcription, the genetic information in DNA is copied into a single-stranded mRNA molecule.
• What are the three main stages of translation?

  1️⃣ Initiation

  2️⃣ Elongation

  3️⃣ Termination
• During elongation, amino acids are joined together by peptide bonds.
• tRNA has two key sites: an amino acid attachment site and an anticodon.


  True
• What shape is tRNA typically folded into?

  Cloverleaf
• The amino acid attachment site of tRNA binds to a specific amino acid
• Steps involved in the function of tRNA

  1️⃣ Carrying amino acids to the ribosome

  2️⃣ Recognizing codons on mRNA

  3️⃣ Facilitating the addition of amino acids to the polypeptide chain
• Ribosomes are composed of two subunits: a small subunit and a large subunit
• What is the role of the small subunit of the ribosome during translation?

  Binds to mRNA
• Adenine in mRNA pairs with uracil in tRNA during codon-anticodon matching.


  True
• Steps involved in the elongation stage of translation

  1️⃣ tRNA Binding

  2️⃣ Peptide Bond Formation

  3️⃣ Translocation
• Translocation in elongation involves the movement of the ribosome along the mRNA.


  True
• Steps involved in the termination stage of translation

  1️⃣ Recognition

  2️⃣ Polypeptide Release

  3️⃣ Ribosome Dissociation
• Phosphorylation involves the addition of phosphate groups to serine, threonine, or tyrosine residues
• What does RNA stand for?

  Ribonucleic Acid
• The sugar in RNA is called ribose
• Match the RNA type with its function:

  mRNA ↔️ Carries genetic code

  tRNA ↔️ Transports amino acids

  rRNA ↔️ Forms ribosomes