DNA, RNA and Protein Synthesis

Question 1

How is DNA stored in eukaryotes?

Answer 1

-Wound around histone proteins
-DNA and histone protein are coiled up tightly to make a chromosome

Question 2

What is a genome?

Answer 2

-The complete set of genes in a cell

Question 3

What is a proteome?

Answer 3

-The full range of proteins that the cell is able to produce

Question 4

What are introns?

Answer 4

-Sections of a polypeptide that don’t code for amino acids

Question 5

What are exons?

Answer 5

-Sections of a polypeptide that do code for amino acids

Question 6

What is an allele?

Answer 6

-A form of a gene

Question 7

What is mRNA?

Answer 7

-Transcription
-Made during transcription
-Carries genetic code from the DNA to the ribosomes
-Single polynucleotide strand

Question 8

What is tRNA?

Answer 8

-Translation
-Carries the amino acids to ribosomes
-Single polynucleotide strand folded into a clover shape
-H bonds between specific base pairs hold the molecule in the shape
-Anticodon
-Amino acid binding site

Question 9

Describe the process of transcription

Answer 9

-RNA polymerase attaches to DNA at the start of a gene
-H bonds between two strands are broken by DNA helicase
-RNA polymerase lines up free nucleotides along exposed bases on template strand
-CBP
-Complementary mRNA strand made
-RNA polymerase moves along DNA, H bonds reform, strands recoil
RNA polymerase reaches stop signal and detaches
-mRNA moves out of nucleus and attaches to ribosome

Question 10

Describe the process of translation

Answer 10

-mRNA attaches to ribosome and tRNA molecules carry amino acids to it
-tRNA molecule, with anticodon, attaches to mRNA by CBP
-Second tRNA molecule attaches itself to the next codon
-Two amino acids joined by peptide bond
-First tRNA molecule moves away, leaving the amino acid behind
-Process continues until there is a stop signal

Question 11

What is the genetic code?

Answer 11

-The sequence of base triplets in mRNA which code for a specific amino acid

Question 12

What does non-overlapping mean?

Answer 12

-Codons don’t share bases

Question 13

What does degenerate mean?

Answer 13

-More possible combinations of triplets than amino acids, so some amino acids are coded for by more than one codon

Question 14

What does universal mean?

Answer 14

-The same specific base triplets code for the same amino acids in all living things