32. Molecular base of heredity. DNA and RNA - structure and functions.

Question 1

Structure of DNA:
- made up of 2 antiparallel strands of joined nucleotides connected together

• nucleotides consist of a deoxyribose sugar (monosaccharides), N base (nitrogenous base) of the purine, pyrimidine origin and a phosphate group
• N base is connected to carbon 1 of deoxyribose sugar by a glycosidic bond
• two nucleotides are bonded together by a phosphodiester bond between carbon 3 of one deoxyribose sugar and carbon 5 of the other deoxyribose sugar
• pyrimidines in DNA are cytosine + thymine
• purines in DNA are adenine + guanine
• bases bind by complementary base pairing - A + T and C + G

Answer 1

Structure of DNA:
- made up of 2 antiparallel strands of joined nucleotides connected together

• nucleotides consist of a deoxyribose sugar (monosaccharides), N base (nitrogenous base) of the purine, pyrimidine origin and a phosphate group
• N base is connected to carbon 1 of deoxyribose sugar by a glycosidic bond
• two nucleotides are bonded together by a phosphodiester bond between carbon 3 of one deoxyribose sugar and carbon 5 of the other deoxyribose sugar
• pyrimidines in DNA are cytosine + thymine
• purines in DNA are adenine + guanine
• bases bind by complementary base pairing - A + T and C + G

Question 2

Structure of RNA:

• same as DNA except, instead of thymine it’s uracil
• single stranded - sugar is ribose instead of deoxyribose

Answer 2

Structure of RNA:

• same as DNA except, instead of thymine it’s uracil
• single stranded - sugar is ribose instead of deoxyribose

Question 3

Functions of DNA:

• control and regulation of cellular activity (transfers genetic messages to all of the cells in your body)
• DNA replication for reproduction and maintenance and growth of cells, tissues and body systems
• codes for proteins which have various important functions
• protein synthesis

Answer 3

Functions of DNA:

• control and regulation of cellular activity (transfers genetic messages to all of the cells in your body)
• DNA replication for reproduction and maintenance and growth of cells, tissues and body systems
• codes for proteins which have various important functions
• protein synthesis

Question 4

Functions of RNA:

• some RNA molecules act as catalysts - ribozymes - they are usually precursors of rRNA, reduce the internal segments of themselves, splicing the ends together
• RNA acts also as ribonuclease, cleaving other RNA molecules
• peptidyl transferase - composed of RNA
• mRNA (messenger RNA) - acts as a template for protein synthesis
• rRNA (ribosomal RNA)- associates with proteins to form ribosomes
• tRNA (transfer RNA) - adapters between mRNA + amino acids (contains own specific amino acid - binds to polypeptide chain if mRNA calls for it), reading of mRNA

Answer 4

Functions of RNA:

• some RNA molecules act as catalysts - ribozymes - they are usually precursors of rRNA, reduce the internal segments of themselves, splicing the ends together
• RNA acts also as ribonuclease, cleaving other RNA molecules
• peptidyl transferase - composed of RNA
• mRNA (messenger RNA) - acts as a template for protein synthesis
• rRNA (ribosomal RNA)- associates with proteins to form ribosomes
• tRNA (transfer RNA) - adapters between mRNA + amino acids (contains own specific amino acid - binds to polypeptide chain if mRNA calls for it), reading of mRNA