Unit 3- Module 2: Protein Synthesis (Transcription & Translation)

What is protein synthesis?

The process cells use to make proteins from genetic instructions in DNA.

What is the central dogma of biology?

The flow of genetic information from DNA to RNA to protein.

What are the two main steps of protein synthesis?

Transcription and translation.

What happens during transcription?

A complementary mRNA copy is made from a DNA gene.

Where does transcription occur in eukaryotic cells?

In the nucleus.

What enzyme builds RNA during transcription?

RNA polymerase.

What does RNA polymerase do?

It binds to DNA, separates the strands in the gene region, and builds a complementary RNA strand.

What happens to mRNA after transcription?

It leaves the nucleus and travels to a ribosome in the cytoplasm.

What happens during translation?

A ribosome reads mRNA codons and links amino acids together to make a protein.

Where does translation occur?

At a ribosome in the cytoplasm.

What is mRNA?

Messenger RNA; it carries genetic instructions copied from DNA to a ribosome.

What is rRNA?

Ribosomal RNA; it combines with proteins to form ribosomes.

What is tRNA?

Transfer RNA; it brings specific amino acids to the ribosome.

What is a codon?

A sequence of three nucleotides on mRNA that codes for an amino acid or a stop signal.

What is an anticodon?

A three-base sequence on tRNA that pairs with a complementary mRNA codon.

What is the job of a ribosome?

It reads mRNA and helps join amino acids to build a protein.

What is an amino acid?

The monomer, or building block, of a protein.

What is a peptide bond?

The chemical bond that links amino acids together in a protein chain.

What is a polypeptide?

A chain of amino acids joined by peptide bonds; it folds to form a protein.

What is the start codon?

AUG; it signals the beginning of translation and codes for methionine.

What are stop codons?

UAA, UAG, and UGA; they signal the end of translation.

What happens when a stop codon reaches the ribosome?

Translation ends and the completed polypeptide is released.

Which RNA base pairs with adenine (A)?

Uracil (U).

Which RNA base pairs with cytosine (C)?

Guanine (G).

How does RNA differ from DNA in its sugar?

RNA contains ribose; DNA contains deoxyribose.

How does RNA differ from DNA in its bases?

RNA uses uracil (U) instead of thymine (T).

What is the shape of RNA compared with DNA?

RNA is usually single-stranded; DNA is a double helix.

Where is DNA located in a eukaryotic cell?

Primarily in the nucleus.

Where can RNA be found in a eukaryotic cell?

In the nucleus and cytoplasm.

What does tRNA deliver to the ribosome?

The specific amino acid that matches its anticodon and the mRNA codon.

How do codons and anticodons pair?

The three bases of an mRNA codon pair with the complementary three bases of a tRNA anticodon.

What determines the order of amino acids in a protein?

The sequence of codons in the mRNA.

How are proteins related to traits?

Proteins perform cell functions and help produce observable traits.

What is an allele?

One version of a gene.

What is a gene?

A segment of DNA that contains instructions for a functional product, often a protein.

What is a nitrogenous base?

A nitrogen-containing part of a nucleotide; DNA uses A, T, C, and G, while RNA uses A, U, C, and G.