(a,c) nucleotides

What is a nucleotide?

• A nucleotide is a type of biological molecule
• A nucleotide is made from a pentose sugar, a nitrogenous base and a phosphate group
• A pentose sugar is a sugar with 5 carbon atoms
• All nucleotides contain the elements carbon, hydrogen, oxygen, nitrogen and phosphorus

Why are nucleotides important?

• Nucleotides are the monomers that make up DNA and RNA
• DNA and RNA are nucleic acids
• DNA and RNA are found in all living cells
• DNA stores genetic information
• Genetic information contains the instructions for growth and development
• RNA is used to make proteins from the instructions in DNA
• Some nucleotides such as ADP and ATP store and transport energy in cells
• The structure of a nucleotide is the same in all living organisms
• Nucleic acids are essential for heredity

What are DNA nucleotides made of?

• the pentose sugar deoxyribose

• a phosphate group

• A nitrogenous base

• The possible bases are adenine, thymine, cytosine and guanine

• A polynucleotide is a polymer made up of nucleotide monomers

What is the structure of DNA?

• DNA is made of two polynucleotide chains

• Each chain contains many nucleotides joined together

What are RNA nucleotides made of?

• pentose sugar ribose

• a phosphate group

• contain one nitrogenous base

• The possible bases are adenine, uracil, cytosine and guanine

• Uracil replaces thymine in RNA

What is the structure of RNA?

• RNA is made of a single polynucleotide chain

What are pyrimidines?

• DNA and RNA bases are classed as either purines or pyrimidines

• Cytosine, thymine and uracil are pyrimidines

• A pyrimidine has one carbon-nitrogen ring

• Pyrimidines are smaller than purines

What are purines

• Adeline and guanine are purines

• Purine base contains two carbon-nitrogen rings joined together

What are ADP and ATP?

• ADP and ATP are phosphorylated nucleotides

• Phosphorylation means adding phosphate groups

• ADP contains adenine, ribose and two phosphate groups

• ATP contains adenine, ribose and three phosphate groups

• ‘Di’ means two and ‘tri’ means three

How is ATP made?

• Energy is released from glucose by respiration

• this energy is used to make ATP

• ATP is made from ADP and inorganic phosphate (Pi)

• ADP is phosphorylated to form ATP

• A phosphate bond is formed

• ATP synthesis occurs in mitochondria

How is ATP used?

• Energy is stored in the phosphate bond of ATP

• ATP is broken down into ADP and Pi

• Energy is released from the phosphate bond

• The released energy is used by the cell