Biology  by Bradford
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6.4 Translation: revision map

The subtopic in the middle and four tasks round it: label a diagram, complete a table, put a process in order and fill 10 gaps. Every box rests on a learning objective of the topic in the AP Biology course and exam description. Type into the blanks and check them, or print it on A4, Letter or A3 with an answer key.

Unit 6 practice questionsThe whole Unit 6 map

Topic 6.4

Translation

AP Biology ยท Unit 6 Gene Expression and RegulationName

6.4.AThe ribosome at work

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  1. 1
  2. 2
  3. 3
  4. 4
  5. 5
  6. 6

6.4.AFrom DNA to amino acid

StepSequence
DNA template strand3' TAC 5'
mRNA codon5' 3'
tRNA anticodon3' 5'
Amino acidmethionine, the start of nearly every polypeptide

There are 64 codons and 20 amino acids, so the genetic code is : several codons code for one amino acid. The same code is used by almost every organism, which is evidence of common ancestry.

Topic 6.4Translation

6.4.AMaking a polypeptide

Number the steps in order.

  1. Elongation: a tRNA with the next amino acid pairs with the next codon.
  2. A peptide bond forms and the ribosome moves along the mRNA by one codon.
  3. Initiation: the small subunit binds mRNA at the start codon AUG, and the first tRNA pairs with it.
  4. The large subunit joins, forming a complete ribosome.
  5. Termination: a stop codon is reached and the polypeptide is released.

6.4.AReading the message

The mRNA is read in groups of three bases called . Each tRNA carries a specific amino acid at one end and has an anticodon at the other which pairs with a codon. Three of the 64 triplets are stop signals and code for no amino acid. After translation, a polypeptide may be folded, cut or joined to others before it is a working protein, and it can be sent to the ER if it carries a signal sequence.

Word bank anticodonAUGcodonslarge subunitmRNApolypeptideredundantsmall subunittRNAUAC

Answer key

Every box on the sheet with its gaps filled in, as the subtopic reads in full.

  1. LabelThe ribosome at work

    1. large subunit
    2. small subunit
    3. mRNA
    4. tRNA
    5. anticodon
    6. polypeptide

  2. OrderMaking a polypeptide

    1. Initiation: the small subunit binds mRNA at the start codon AUG, and the first tRNA pairs with it.
    2. The large subunit joins, forming a complete ribosome.
    3. Elongation: a tRNA with the next amino acid pairs with the next codon.
    4. A peptide bond forms and the ribosome moves along the mRNA by one codon.
    5. Termination: a stop codon is reached and the polypeptide is released.

  3. TableFrom DNA to amino acid

    StepSequence
    DNA template strand3' TAC 5'
    mRNA codon5' AUG 3'
    tRNA anticodon3' UAC 5'
    Amino acidmethionine, the start of nearly every polypeptide

    There are 64 codons and 20 amino acids, so the genetic code is redundant: several codons code for one amino acid. The same code is used by almost every organism, which is evidence of common ancestry.

  4. GapsReading the message

    The mRNA is read in groups of three bases called codons. Each tRNA carries a specific amino acid at one end and has an anticodon at the other which pairs with a codon. Three of the 64 triplets are stop signals and code for no amino acid. After translation, a polypeptide may be folded, cut or joined to others before it is a working protein, and it can be sent to the ER if it carries a signal sequence.