8.3 - Structures of Ribonucleic Acid

Question 1

What is a codon?

Answer 1

• the sequence of 3 bases on mRNA that codes for an AA

Question 2

What is the genome?

Answer 2

• the complete set of genes in a cell, inc. those in mitochondria + chloroplasts

Question 3

What is the proteome?

Answer 3

• the full range of diff. proteins the genome is able to code for

Question 4

How does RNA differ to DNA?

Answer 4

• single stranded (instead of double)
• contains uracil instead of thymine
• nucleotides contain pentose sugar ribose (instead of deoxyribose)
• smaller
• found throughout cell (instead of mostly in nucleus)
• less stable

Question 5

What are the 2 types of RNA important in protein synthesis?

Answer 5

• messenger RNA (mRNA)
• transfer RNA (tRNA)

Question 6

What determines the base sequence of mRNA?

Answer 6

• the sequence of bases on a length of DNA 

Question 7

What happens once the mRNA is formed?

Answer 7

• it leaves the nucleus via pores in the nuclear envelope + enters cytoplasm where it associates w the ribosomes

Question 8

What does the sequence of codons in mRNA determine?

Answer 8

• the AA sequence of a specific polypeptide

Question 9

How many nucleotides is a tRNA molecule roughly made out of?

Answer 9

• 80

Question 10

What are the features of a mRNA molecule?

Answer 10

• linear
• has a codon

Question 11

What are the features of a tRNA molecule?

Answer 11

• clover leaf shape
• has hydrogen bonds
• has an amino acid binding site
• has an anticodon

Question 12

How is mRNA different to tRNA?

Answer 12

• bigger
• single helix/linear (not clover shaped)
• less stable
• no hydrogen bonds
• has codon (not anticodon)
• no AA binding site

Question 13

How is mRNA + tRNA similar?

Answer 13

• both single stranded
• both nucleotides have ribose
• both have bases (A,G,C + Uracil)
• both made in nucleus + found throughout cell
• both quantities vary from cell to cell + w lvl of metabolic activity