Molecular Basis Of Inheritance

Molecular Basis Of Inheritance

Nucleic acids.

• •Nucleic acids are the macromolecules present in all living cell.

  
  

• Freidrich Miescher was the first person isolated the nucleic acids from the pus cells. He called it as nuclein

• As it has an acidic nature, hence Altmann called it as nucleic acids.

The two types of nucleic acids found in living organisms are

• Deoxyribonucleic acid [DNA]

• Ribonucleic acid [RNA]

• DNA and RNA are nucleic acids that carry out cellular processes especially regulation and expresssion of genes

Nucleic acid composition

• Both DNA and RNA are made of nucleotides containing

• a five carbon sugar

• a phosphate group

• a nitrogenous base

From Nucleotides Into Polymers

• DNA is double helix made of two antiparallel strands of nucleotides linked by hydrogen bonding between complementary base pairs.

• Phosphate-Sugar Backbone

• The Nucleic Acid Ladder

Antiparallel Strands

• 5 PRIME = The phosphate end is called the 5' end because the fifth carbon is closest to the phosphate group.

• 3 PRIME = The sugar end is called the 3' end because the third carbon is closest to the sugar.

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Multiple Choice

Which of the following is true of DNA but not of RNA?

• It is made up of a single strand of nucleotides.

• It contains the sugar deoxyribose.

• It leaves the nucleus to translate protein.

• It contains the nitrogen base uracil.

Multiple Choice

What does DNA have that RNA doesn't

• Presence of thymine

• Presence of deoxyribose

• Presence of ribose

• Both a and b

Multiple Choice

DNA is a polymer made of ______

• sugars

• amino acids

• fats

• nucleotides

Multiple Choice

The steps (rungs) of the DNA ladder are made up of __________.

• phosphate groups

• sugars

• nitrogen bases

• amino acids

Multiple Choice

What is the nature of the strands of the DNA duplex?

• Anti-parallel and complementary

• Identical and complementary

• Anti-parallel and non-complementary

• Dissimilar and non-complementary