1.3 Gene Expression

Question 1

Compare the DNA and RNA

Answer 1

1. RNA is single-stranded, where DNA is double-stranded
2. RNA has a ribosome suger where DNA has a deoxyribose suger
3. RNAs Adenineis complementary to Uracil where DNA s Adenine is complemenety to Thymine
4. RNA is found in the nucleus and cytoplasm where DNA is only found in the nucleus

Question 2

State the 3 types of RNA

Answer 2

mRNA - Messrnger RNA
tRNA - transfer RNA
rRNA - Ribosomal RNA

Question 3

Describe the things that are involved in the process of protein synthesis

Answer 3

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Question 4

4 Things

Describe the process of transcription

Answer 4

1. RNA polymerase moves along the dna unwinding the DNA and breaking the hygogen bonds
2. As RNA polymerase breaks the bonds it synthesis a primary transcript of mRNA using RNA nucleotides. These form hygogen bonds with the exposed DNA strand by complemenrty base pairing.

. RNA Splicing forms a mature transcript as the introns are removed and the exons are kept

Different proteins can be expressd because of alternitive splicing.

Question 5

2 Things

Describe the process of making a mature transcript

Answer 5

First the gene is copied in full to produce a primary transcipt. this includes both introns and exons

then RNA splicing occurs to remove the introns and to join the remaining exons together.

Question 6

7 Things

Describe the process Of translation

Answer 6

Once mRNA is out of the nucleus it travels to the ribosome

tRNA molecules have a triplet of unbaired bases called the antioden and a region where a specefic amino aid can attach

mRNA molecules travel through th cytoplasm and attaches to the ribosome.

Each mRNA codon codes for a specific protein. The first codon of an mRNA is a START codon.

The anticodons and codons match up and form complementry bsdr pairs so the genetic code is translated into na sequence of amino acids.

Peptide bonds form between the amino acids to form a polypetide

Used tRNA molecules exit the ribosome and collects another specefic amino acid.

Question 7

Describe how DNA and RNA bases code for amino acics

Answer 7

Each Triplet of bases is called a codon and codes for a specefic amino acid.

Question 8

Describe alternative splicing

Answer 8

Different proteins can be expressed from one gene as a depending on which exons are retained.

Question 9

Describe the type of bonds which form a protein

Answer 9

Peptide bonds

Question 10

State what determines a proteins phenotype

Answer 10

Enviromental factors and…

Question 11

State the function of mRNA

Answer 11

Carries a copy of the DNA code from the nucleus to the ribosome

Question 12

State the function of tRNA

Answer 12

The tRNA molecule has an anticoden at one end and an attachment site for a specefic amino acid at the other end.

Question 13

State the function of rRNA

Answer 13

Ribosomal RNA and proteins form the ribosome.