bio quiz #2

Question 1

what are the differences between DNA and RNA?

Answer 1

1) RNA: Ribose instead of Deoxyribose (sugar)
2) RNA is single-stranded, DNA is double-
stranded
3) Thymine is replaced by Uracil in RNA (->
Adenine)

Question 2

Transcription

Answer 2

RNA polymerase (enzyme): Binds at beginning of gene on DNA (promoter region) Promoter region has distinct nucleotide sequence. RNA polymerase unzips the DNA double helix, uses one strand as template and ties together complementary nucleotides. Result: single-stranded RNA molecule.

Question 3

Translation

Answer 3

(1) Ribosomes ‘sandwich’ mRNA strand and travel along the strand. (2) Ribosome binds specific molecules, transfer RNA (tRNA), which carry amino acids. (3) Ribosome travels along mRNA and binds 2 tRNA molecules with matching anticodons at a time. 4) Ribosome connects amino acids in sequence of the codons Result: Growing chain of amino acids = protein until it hits stop codon.