Nucleic acids and ATP Flashcards
Draw/describe the structure of a nucelotide
o phosphate group
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I
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Rectangle (Nitrogen containing base)
pentagon(pentose sugar)
The monomer that makeus up DNA is called a nucelotide and it is made up of a deoxyribose (pentose sugar) a nitrogen containing base and one phostphate group.
The nitrgenous base can either be guanine cytosine adenine and thymine
Pentose sugar (pentagon)
Phosphate group (circle on top of pentagon)
Nitrogen containing base (rectangle on top of pentagon)
What is DNA
Deoxyribonucleic acid (DNA) codes for the sequence of amino acids in the primary structure of a protein which in turn determines the final 3D structure and function of a protein.
Cells must contain a copy of this genetic code so that it can be passed on to new cells without being damaged.
The DNA polymer is a double helix
State the role of DNA in living cells
Base sequence of genes code for functional RNA and amino acid sequence of poly peptides.
Genetic information determines inherited charecteristics which influences the structure and function of organisms.
What are polynucleotides
Polymer of nucelotides created by condensation
How do polynucelotides form
Condensation reaction between nucelotides form strong phophodiester bonds (sugar phosphate backbone) strong covalent bonds holding the polymer together
Condensation reaction between pentose sugar and the phosphate group creating a phosphodiester bond which are strong covalent bonds ensuring genetic code is not broken down.
Describe the structure of polynucelotides
The Dna polymer occurs in pairs joined by hydrogen bonds between the bases. Two chains twist making the double helix.
Hydrogen bonds can only form between complementary base pairs (cytosine and guanine) (adrenine and thymine)
Adenine and thymine form 2 hydrogen bonds where as cytosine and guanine form 3 hydrogen bonds. these base pairings maintaain order of genetic code when Dna replicates
Name the complementary base pairings in DNA
2 hydrogen bonds between Adeine and Thymine
3 hydrogen bonds between Cytosine and guanine
Name the complementary base pairs in RNA
2 hydrogen bonds between adenine and urcail
2 hydrogen bonds between guanine and cytosine
Relate the structure of DNA to it’s functions
- Sugar phosphate back bone (covaelnt bonds) and many H bonds provide stability
- Long/large molecule stores lots of information
- helix is compact for storage in nucleus
- base sequence of triplets codes for amino acids
- double stranded for semi conservative replication (using one strand as template)
- complementary base paring for accurate replication identical copies to be made
- weak H bonds break so strands seperate for relication (easy unzipping of two strands in double helix)
Why do cells replicate
Before cells divide by mitosis or meiosis all the Dna must replicate to provide a copy for the new cell.
The process of DNA replication is semi conservative replication (in the daughter DNA one stramd is from the parental DNA and one is newly synthesises)
Daughter dna (DNA you create)
Parental DNA (DNA you already have/orignal)
Outline the process of semi conservative replication?
- DNA helicase breaks H bonds between base pairs causing DNA double helix to unwind
- Each strand serves as a template for the formation of a new complementary strand.
- Free DNA nucleotides in the nucleus bind to their complementary bases on the exposed template strands on the parental DNA (A with T, C with G).
- DNA polymerase catalyzes the joining together of adjjacent nucelotides (formation of phosphodiester bonds between adjacent nucleotides), forming a new strand.
- Hydrogen bonds form between the complementary base pairs, restoring the double helix structure.
- TWo sets of daughter DNA (new DNA) molecule consists of one old and one newly synthesised strand
What is RNA
RNA is a polymer of a nucelotide formed of a ribose nitrogenous base and a phosphate group.
Adenine guanine cytosine and uracil
RNA has the base uracil instead of thymine. In comparison to DNA polymer the RNA polymer is short polynucleotide chain and is single stranded.
Its function is to copy and transfer the genetic code from DNA in the nucleous to the ribosomes. Some RNA is alspo combined with proteins to create ribosomes.
