2.2 Nucleic Acids Flashcards
What are the two types of nucleic acid?
DNA- deoxyribose nucleic acid
RNA- ribose nucleic acid
What are nucleotides?
Monomer units making up nucleic acids (polymer)
What are nucleotides made up of?
- carbon
- hydrogen
- oxygen
- nitrogen
- phosphorus
What are the 3 components of a nucleotide?
- phosphate group
- a sugar
- a base
What are nucleic acids?
Biochemical macromolecules involved with the transmission of inherited information
What are the two types of nucleotide bases?
- purines
* pyramidines
What base is the biggest?
Purines
What are purines and what are the two purines?
Double ringed structures that always pair up with pyramidines
• adenine
• guanine
What are pyramidines and what are the two types?
Single ringed structures that always pair up with purines
• thymine
• cytosine
• uracil (only found in RNA)
How do purines bond to pyramidines?
By hydrogen bonds
What reaction occurs to form a nucleotide?
A condensation reaction as two water molecules are lost
How is a nucleotide formed?
A nucleotide is formed when a phosphoric acid and a base are chemically bonded to a sugar molecule
When is water given off?
When the phosphate group and base groups are joined
When is a polynucleotide formed?
When many nucleotides join
When is a dinucleotide formed?
When 2 nucleotides are covalently linked by a condensation reaction
In the formation of a dinucleotide where does the linkage occur?
Between the phosphate group of one nucleotide and the sugar if another
What is the linkage in the formation of a nucleotide called?
A PHOSPHODIESTER bond
1 ester bond, 2 nucleotides joined
What is the backbone in DNA called?
A sugar phosphate backbone
What bases pair together in DNA?
Adenine and Thymine
Guanine and cytosine
What are DNAs bases joined by?
Hydrogen bonding
What is DNAs structure?
A double stranded helix
Is ribonuclease acid single stranded or double stranded?
Single
What are the three types of RNA?
- ribosomal RNA
- transfer RNA
- messenger RNA
What is ribosomal RNA?
the structural component of ribosomes
What does transfer RNA do?
It transports amino acids to ribosomes
What does messenger RNA do?
It transfers genetic information from DNA to ribosomes
What is ATP?
Adenosine triphosphate (energy)
What biological processes require energy to occur?
- muscle contraction
- cell division
- transmission of nerve impulses
- memory formation
What do cells require energy for? Give examples
- synthesis -e.g. Of large molecules such as proteins
- transport - e.g. Pumping molecules or ions across cell membranes by active transport
- movement- e.g. Protein fibres in fibres of muscle cells that cause muscle contraction
Where is ATP made and what is it?
It is made in the mitochondria and is a nucleic acid
What base does ATP contain?
Adenine
What is ATP made up of?
- ribose (pentode sugar)
- adenine
- 3 phosphate groups
What does AMP have? (adenosine monophosphate)
• 1 phosphate group
What does ADP have (adenosine diphosphate)?
• two phosphates are joined
What does ATP have? (Adenosine triphosphate)
• three phosphate groups
What forms when ATP is broken down?
Breaks down to form ADP and a phosphate ion
What reaction occurs to release energy from ATP?
• hydrolysis of the ATP releasing large amounts of energy which can be used for various energy requiring reactions
Why is ATP used instead of glucose to release energy?
- glucose takes too long to release energy and releases too much energy at once so it is wasted
- so glucose is first turned to ATP and then broken down
How is ATP formed?
By adding a phosphate group to a molecule of ADP
What reaction occurs to form ATP from ADP?
A condensation reaction
Where is energy supplied from in the reaction to form ATP?
Respiration
What are the properties of ATP?
- small
- water soluble
- immediate energy release
- releases energy in small quantities
- easily regenerated
Why is it useful that ATP is small?
It can move in, out and within cells easily
Why is it useful that ATP is water soluble?
Energy requiring processes occur in aqueous environments
Why is it useful that properties of ATP allow easy energy release?
Bonds between phosphates allow for immediate energy release, they aren’t too large to be wasted, but large enough to be used for cellular reactions
Why is it useful that energy is released in small quantities?
Energy is not wasted
Why is it useful that ATP is easily regenerated?
It can be recharged with energy, ADP can do back to the mitochondria to make ATP
Why does the reaction from ATP to ADP make energy instantly available?
It is a single reaction
ATP + H2O =
ENERGY + ADP + Pi
