What is a phosphodiester bond?
A covalent bond formed between two nucleotides in a condensation reaction. (5 C phosphate group to 3 C)
What is the function of nucleic acids?
The storage and transfer of genetic information and synthesis of proteins.
Describe the structure of a nucleotide.
A nucleotide molecule (can be DNA or RNA) consist of a pentose sugar, a nitrogen containing base and a phosphate group.
What are the differences between DNA and RNA?
DNA:
- Double Stranded
- Larger Molecule (cannot exit nuclear pores)
- Contains Thymine
- Contains Deoxyribose pentose sugar
- Requires DNA Polymerase
- Found in chromosomes in nucleus
What is the function of DNA?
To store genetic information and code for the production of proteins.
What is the structure of DNA?
- Two polypeptide chains
- Anti-parallel formation
- Hydrogen bonds between complementary nitrogen containing bases (Allows DNA to be transcribed)
- Double helix structure.
What is the structure of ATP?
A ribose sugar, a nitrogen containing base (adenine) and three inorganic phosphate groups.
What is the purpose of ATP?
An immediate source of energy for metabolic reactions and synthesis of biological molecules.
How does the structure of ATP make it a good source for energy?
- The bonds between the phosphate groups have a low activation energy so they are easily hydrolysed to release energy
- Small, moves easily out of cells
- Water soluble
- Contains bonds between phosphates with immediate E, large enough to be sufficient for cellular respiration, but not so large to waste E as heat
- Releases energy in small quantities
- Easily regenerated
Which bases are the pyrimidines?
Smaller bases which contain single carbon ring structures:
- T,C,U
Which bases are the purines?
Larger bases which contain double carbon ring structures
- A,G
Why must a purine always bond to a pyrimidine?
Provide an even double helix, no bulges/unable to reach
What is adenosine?
Adenine + Ribose
What do we use ATP/ Energy for?
- Synthesis
- Movement
- Transport
Why is ATP not a long term energy store?
What is our long term energy store?
Immediate because of instability of phosphate bonds
Fat!
What is the difference between DNA in prokaryotes and DNA in eukaryotes?
Prokaryotes:
- Circular DNA with no free ends
- Relatively short
- Not bound to histones
Eukaryotes:
- Linear DNA with two ends
- Longer
- Tightly wrapped around histone proteins
What is the universal code?
- 3 nucleotides code for one codon
- Multiple amino acids code for the same codon
- All organisms contain DNA
- Non-overlapping
What is the structure of ADP/ATP?
A ribose sugar, nitrogenous base and inorganic phosphates
Explain semi-conservative DNA replication:
Describe transcription:
Describe translation:
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Plant Transport43
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Neuronal Communication16
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Excretion22
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Biological Molecules38
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Diseases22
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Exchange3
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Transport8
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Homeostasis21
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Animal Responses46
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Membranes0
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Nucleic Acids21
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Enzymes2
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Classification and Evolution0
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Biodiversity0
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Cell Division15
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Cell Structure16
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Respiration19
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Cellular Control11
