Chapter 5 Nucleic Acids and their Functions Flashcards
Define nucleotide
Monomer of nuclei acid comprising of a pentose sugar, a nitrogenous base and a phosphate group.
What are the two types of organic bases?
Pyrimidines
Purines
What are examples of pyrimidines?
Thymine, cytosine, uracil
What are examples of purines?
Adenine and guanine
What does ATP stand for?
Adenosine triphosphate
Why is ATP called the ‘universal energy currency’?
It is involved in energy changes in all living organisms.
What is the structure of ATP?
Adenine, ribose and 3 phosphate groups.
How does ATP release energy?
The enzyme ATPase hydrolyses the bond between the second and third phosphate groups, removing the third one. This produces ADP and a phosphate ion with the release of chemical energy.
How is ATP synthesised?
ADP and a phosphate ion can combine in a condensation reaction, to make ATP and water. The addition of a phosphate to ADP is called phosphorylation.
How much energy does the hydrolysis of ATP produce?
-30.6 KJmol^-1
What are the biological roles of ATP?
Metabolic processes
Active transport
Nerve transmission
What does DNA stand for?
Deoxyribose nucleic acid
What is the structure of DNA?
Two polynucleotide strands wound in a double helix. The pentose sugar is deoxyribose and the four nitrogenous bases are adenine, thymine, cytosine and guanine.
What are the complementary base pairs?
Adenine with thymine
Cytosine and guanine
What bonds hold the complementary base pairs?
Hydrogen bonds
Why is DNA suited to its function?
It is a stable molecule
It is a large molecule allowing it to carry a large amount of genetic information
The two strands are able to separate
The genetic information is protected by the sugar-phosphate backbone
What does RNA stand for?
Ribonucleic acid
What is the structure of RNA?
Single stranded polynucleotide containing the pentose sugar ribose. It contains the bases adenine, uracil, cytosine and guanine.
What are the three types of RNA involved in protein synthesis?
Messenger RNA (mRNA) Ribosomal RNA (rRNA) Transfer RNA (tRNA)
What is the role of mRNA in protein synthesis?
It is synthesised in the nucleus and carries the genetic code from the DNA to the ribosomes in the cytoplasm.
What is the function of rRNA in protein synthesis?
Found in the cytoplasm and is a constituent of ribosomes.
What is the function of tRNA in protein synthesis?
Carries anticodons and transports specific amino acids to the ribosomes.
