Transcription and Translation

Question 1

Parent DNA

Answer 1

Original strand of DNA

Question 2

Daughter DNA

Answer 2

2 new replicated strands

Question 3

Origins of replication

Answer 3

Site where DNA replication begins

Question 4

DNA polymerase

Answer 4

Enzyme that assists with DNA replication.

Question 5

Steps of DNA replication

Answer 5

1. Double helix unwinds, 2 strands separate
2. DNA polymerase lines up nucleotides to form 2 new second strands. Nucleotides line up according to base pairing rules.
3. Hydrogen bonds form between base pairs, forming new rungs. Sugar-phosphate components bond to form sides of the ladder.
4. The new double stranded molecules twist into double helixes.
   Occurs in the nucleus

Question 6

Template

Answer 6

Each DNA strand acts as a template for the formation of a new complementary strand. Nucleotide bases direct the construction of a complementary strand.

Question 7

Somatic cell

Answer 7

Non-sex cell

Question 8

How many chromosomes does a somatic cell have?

Answer 8

Each has 23 pairs, 46 in total.

Question 9

Diploid

Answer 9

A cell with 2 sets of chromosomes, like a human cell.

Question 10

Homologous Chromosomes

Answer 10

1. Each person gets 23 chromosomes from one parent and 23 from the other. The 1st, 2nd, etc from each form a homologous pair.
2. These chromosomes are not identical

Question 11

Genes

Answer 11

Portion of DNA that carry protein instructions.

Question 12

What do chromosomes do?

Answer 12

1. DNA carries instructions for making proteins or creating amino acids. Enzymes can create everything else necessary for the cell.

Question 13

Transcription

Answer 13

Going from DNA to RNA

Question 14

Translation

Answer 14

1. Going from RNA to proteins
2. Occurs in the cytoplasm
3. RNA must leave nucleus and enter cytoplasm for translation to occur.

Question 15

RNA transcription

Answer 15

1. DNA molecule unwinds
2. RNA polymerase creates a complementary strand of RNA, using one strand of DNA and base pairing rules
   Occurs in the nucleus

Question 16

In RNA transcription, do DNA and RNA bond together?

Answer 16

No, RNA is a single stranded molecule. RNA is released and DNA rejoins its complementary partner.

Question 17

How much of a DNA molecule is used to make RNA?

Answer 17

Only a small portion. Only the genes that correspond to the proteins needed by the cell are used.

Question 18

Messenger RNA (mRNA)

Answer 18

RNA that actually carries information for protein synthesis (in the form of a nucleotide sequence) from DNA in the nucleus to ribosomes in the cytoplasm.

Question 19

Ribosomal RNA (rRNA)

Answer 19

Interacts with the cell’s ribosomes to make them functional. Ribosomes are made of rRNA and protein

Question 20

Transfer RNA (tRNA)

Answer 20

1. Carries amino acids from cytoplasm to ribosomes during protein synthesis.

Question 21

Codon

Answer 21

Sequence of 3 nucleotides, which correspond to one amino acid in translation. Order of codons on mRNA specifies the order of amino acids on a protein. Read in a nonoverlapping sequence.

Question 22

Which are the start and stop codons?

Answer 22

1. Start is the first on all mRNA. AUG (methionine)

2. Stop: UAA, UGA, UAG

Question 23

tRNA structure

Answer 23

Has a clover leaf shape. An anticodon is contained in the anticodon loop at one end.

Question 24

Anticodon

Answer 24

Region on tRNA molecule that can base pair with codons on mRNA. Must be complementary.
Example: codon is AUG, anticodon must be UAC

Question 25

Amino acid attachment site

Answer 25

At the other end of tRNA, an amino acid can attach. The amino acid corresponds with the codon that the tRNA anticodon can base pair with. mRNA codon and tRNA anticodon are like base pairs and have the same amino acid attached.

Question 26

Binding sites on a ribosome

Answer 26

1. P-site: peptide site where the peptide is attached to the ribosome
2. A-site: amino acid site where the next amino acid is added to the growing protein.
3. mRNA binds to the ribosome so the first codon is the P-site and the second is the A-site.

Question 27

Translation Steps

Answer 27

1. mRNA binds to ribosome P-site and A-site
2. tRNA, carrying amino acids, base pairs with codons on mRNA.
3. Ribosome forms a peptide bond between the 2 amino acids.
4. The first tRNA, now empty, is released to the cytoplasm and can bind another amino acid
5. The ribosome slides down one codon, so that the codon that was in the A site shifts to the P site, and the next codon in sequence moves to the A site
6. The sequence of steps is repeated until every codon has been base paired and are considered translated.
7. When a stop codon appears in the A-site, the final tRNA is released and the transaction is complete.