L16.5-DNA transcription & translation & L16.9-Univ. genetic code

L16.5-DNA Transcription & Translation

L16.9-Universal Genetic Code

​CENTRAL DOGMA - DNA is transcribed into RNA, and RNA is translated into an amino acid sequence (protein). That protein functions to cause a phenotype, or observable trait

PROTEIN SYNTHESIS

Protein synthesis = a process through which the genes in DNA are expressed into proteins.

DNA                      RNA                     PROTEIN

Transcription

What is transcription?

Where does it occur?

What structures/enzymes are needed?

What is the end result?

Translation

What is translation?

Where does it occur?

What structures/enzymes are needed?

What is the end result?

​Let's transcribe and translate!

TRANSCRIBE THE CODE BELOW FIRST:

TAC – TTC – AAA – CCG – CGT – GGG - ATT

NOW TRANSLATE IT!

​PRACTICE: TRANSCRIBE & TRANSLATE THE FOLLOWING DNA SEQUENCES

1. GTA-CGC-GTA-TAC-CGA

2. TTT-ACG-GCC-ATC-AGG

3. GAA-GTC-TGG-AAA-CCT-TAT-TAG

4. TAC-CGT-ATA-GGC-CGA-TGC-ATT-CAT

Transcription & Translation

​	​Transcription	​Translation
Define	​	​
Location	​	​
​Participants	​	​
​Outcome	​	​

Multiple Choice

A diagram of a cellular process is shown below.

Which of the following identifies the process shown at point Z?

• Translation

• Translocation

• Replication

• Transcription

Multiple Choice

Which of the following carries amino acids to the site of protein synthesis?

• mRNA

• tRNA

• rRNA

• nRNA

Multiple Choice

During transcription the DNA base sequence is transcribed into a complimentary mRNA sequence. A codon table like the one shown below lists the amino acids coded for by particular triads of mRNA bases. A segment of DNA has undergone a mutation in which one nucleotide has been changed. The original sequence was ACG and the new sequence is ACA. Use the codon table to determine whether or not this mutation will cause a change in the phenotype of the organism.

• yes, the phenotype of the organism would change because a new amino acid will be coded

  for.

• yes, the phenotype of the organism would change because any change in the DNA

  sequence will cause a change in phenotype.

• Even though the DNA sequence changed, the sequence still codes for the

  same amino acid, so no change in phenotype will occur.

• It is impossible to determine if a change in phenotype will occur using only the

  DNA sequence.

Multiple Choice

Genes for medically important proteins can be cloned and inserted into bacteria, as shown in the diagram below.

Why can bacteria recognize a human gene and then produce a human protein?

• DNA replication in bacteria and humans is the same.

• Bacterial cells contain the same organelles as human cells.

• The basic components of DNA are the same in humans and bacteria.

• Bacterial cells and human cells contain the same kind of chromosomes.

Multiple Choice

The sequence of DNA below is part of a gene. How many amino acids are coded for by this segment?

5' ATCAGCGCTGGC 3'

• 4

• 8

• 12

• 20

Multiple Choice

1.An original DNA strand with the sequence ACG – CCA – TGA – AAG is used as a template to make a new strand during DNA replication. What would be the complementary sequence of the new DNA strand?

• UGC-GGU-ACU-UUC

• TGC-GGU-ACT-UUC

• TGC-GGT-ACT-TTC

• TGG-CCT-ACT-TTG

Multiple Choice

1.An original DNA strand with the sequence ACG – CCA – TGA – AAG is transcribed onto mRNA. What would the sequence be like?

• UGC-GGU-ACU-UUC

• TGC-GGU-ACT-UUC

• TGC-GGT-ACT-TTC

• TGG-CCT-ACT-TTG

Multiple Choice

If the sequence of nucleotides, TAAGCGAAAGCA, goes through protein synthesis, assuming that there are no STOP codons, how many amino acids will be made?

• 4

• 6

• 3

• 12

Multiple Choice

Reference the DNA sequence within a gene reads: TCC AAT GGC CTG TTT GCA What sequence of amino acids is specified by this DNA sequence?

• Arg-Leu-Pro-Asp-Lys-Arg

• Thr-Phe-Iso-Arg-Stop

• Trp-Phe-Leu-Gly-Asp-Ser

• Ser-Leu-Pro-Asp-Lys-Arg

Multiple Choice

A scientist discovers a protein with the sequence Met-Cys-Val.Which mRNA sequence mightcode for this protein?

• AUGUGCGUG

• UACACGCAC

• GUGCGUGUA

• CACGCACAU

Multiple Choice

The diagram below shows an important biochemical process that occurs in cells.

Which process is represented?

• Transcription

• Translation

• DNA replication

• Protination

Multiple Choice

The fact that a strain of yeast with a certain defective gene can use the human version of the gene to repair itself is evidence of which of the following?

• Yeast and humans share a universal genetic code.

• Yeast and humans have identical DNA in their genomes.

• Yeast and humans both have prokaryotic chromosomes.

• Yeast and humans depend on the same food supply.

Multiple Choice

A scientist puts nucleotide chains of UUUUUU in a test tube under conditions allowing protein synthesis. Soon the test tube is full of polypeptide chains composed only of the amino acid phenylalanine. What does this experiment indicate?

• The amino acid phenylalanine is composed of uracil.

• UUU codes for the amino acid phenylalanine.

• Protein synthesis malfunctions in test tubes.

• Most proteins contain only one type of amino acid.

Multiple Choice

A segment of DNA has this sequence:

ATA GCA CAT GTA

What is the mRNA sequence transcribed from this segment?

• TAT CGT GTA CAT

• TAT GCT CTA GAT

• UAU CGU GUA CAU

• UAU GCU CUA CAU

Multiple Choice

What are the subunits of DNA and their function?

• nucleotides that store information

• monosaccharides that provide quick energy for the cell

• lipids that store energy and provide insulation

• proteins that provide the building blocks for the structural components of

  organisms

Multiple Choice

This chart shows which amino acids are coded for by different combinations of mRNA nucleotides.

Which amino acids are coded for by an mRNA segment that reads CAG GUG?

• arginine and valine

• isoleucine and arginine

• glutamine and valine

• valine and isoleucine

Multiple Choice

How does DNA code for proteins in a cell?

• by creating a new double helix structure

• by using its phosphate and sugar molecules

• by adding more hydrogen bonds to its structure

• by arranging certain nitrogen bases of the cell in a particular order

Multiple Choice

The genetic code is nearly universal, meaning that almost all organisms use the

same genetic code. Which statement does NOT explain why the genetic code is

nearly universal?

• All organisms can grow, respond to stimuli, and reproduce.

• All organisms are genetically related to all other organisms.

• All organisms use each codon for the same amino acid.

• All organisms encode their genes using DNA or RNA.

Multiple Choice

According to the genetic code, the mRNA codon UCG codes for the amino acid

serine in frogs, humans, and horses. What does this fact tell you?

• A mutation in one base will always have a physical effect on the

  resulting protein.

• The genetic code does not dictate the amino acid sequence of proteins.

• The genetic code is the same for nearly all organisms.

• A mutation in one base could have absolutely no physical effect on the

  resulting protein.

Multiple Choice

The genetic code is nearly universal. That means, with few exceptions, the same

codons code for the same amino acids in all organisms. What does the near

universality of the genetic code suggest?

• All life-forms arose about the same time in Earth’s history.

• All life-forms have a common evolutionary ancestor.

• All life-forms can reproduce with one another.

• All life-forms have the same number of genes.

Multiple Choice

Look at the image above. Translate the following codons from a pig's mRNA

strand: UCC AGG UUA. What amino acids does this code for and would the

same codons from a bacteria code for the same amino acids?

• It codes for serine, arginine, and leucine. The same codons in a pig

  would code for the same amino acids in a bacterium because the

  genetic code is universal.

• It codes for arginine, serine, and asparagine. The codons from a pig

  would be different from a bacterium because they look different and so

  they will be made from different amino acids.

• It codes for arginine, serine, and asparagine. The same codons in a pig

  would code for the same amino acids in a bacterium because the

  genetic code is universal.

• It codes for serine, arginine, and leucine. The codons from a pig would

  be different from a bacterium because they look different and so they

  will be made from different amino acids.

Multiple Choice

Which factor most affects the order of amino acids in a protein?

• the DNA located in the nucleus of the cell

• the cell in which the protein is located

• the amount of ATP available for the cell’s use

• the area in a cell where proteins are produced

Multiple Choice

Which statement best describes the relationship that exists among proteins, DNA,

and cells?

• Proteins combine to produce cells, which produce DNA.

• Proteins are made up of DNA, which determines the cells that are produced.

• DNA is made up of proteins, which tell a cell how to function.

• Cells contain DNA, which controls the production of proteins.