CH 4: A. Nucleotides, B. Polynucleotides

What are the monomers of nucleic acid

they are called nucleotides

What are the polymers of nucleotides

they are called Polynucleotides

What are the major types of nucleic acids

DNA (deoxyribonucleic acid)

RNA (ribonucleic acid)

Adenosine Triphosphate (ATP)

Main functions of major nucleic acids

DNA stores genetic info

RNA transport genetic info

ATP - source of energy

Nucleotides (components)

consists of a

• Pentose sugar

• Phosphate group

• Nitrogenous base

Pentose sugar (structure)

a sugar with 5 carbon

shaped like a ring with oxygen at top of pentagon, a carbon each connecting the rest

Nitrogenous base will be connected to Carbon 1

Phosphate group will be connected to Carbon 5

2 families of Nitrogenous Bases

• Pyrimidines

• Purines

Pyramidines (Nitrogenous base)

a 6-pointed ring either…

• cytosine

• Uracil (used in RNA)

• Thymine (used in DNA)

smaller molecules

Purines (Nitrogenous base)

a 6-pointed ring either Adenine or Guanine attacthed to a 5 pointed ring

larger molecules

Why DNA has deoxyribose

and RNA has ribose

While both their C1 and C5s connected to same bases

the RNAs C2 and C3 are each attached to OH (hydroxyl)

the DNA’s C2 are attached to a H and C3 is attached to an OH thus Diff

Polynucleotide

chain of nucleotides (pentose sugar + nitrogenous base + phosphate group)

ex. dna is a double stranded polynucleotide

rna is a single stranded polynucleotide

Phosphodiester bond

bond that links nucleotides into polynucleotides.

It forms when the phosphate group of one nucleotide connects to the hydroxyl group (OH) on the 3' carbon of the pentose sugar of another nucleotide. This reaction releases a molecule of water (H₂O) and creates a bond between the remaining oxygen of the phosphate group and the 3' carbon of the sugar. This process results in the formation of the sugar-phosphate backbone of nucleic acids, such as DNA and RNA.

Describe the backbone of a nucleotide

backbone is made out of polynucleotides (sugar and phosphate units inside and nitrogenous bases sticking out

there will be a Carbon 5 connection at start and C3 connection at the end of backbone