2.3 Nucleic Acids

Critically acclaimed reviser, Ethan Bungay, returns with what appears to be another set of flash cards. Critics are raving over '2.3 Nucleic Acids', describing it as the "best of all module 2".

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  • Created by: elbungay1
  • Created on: 19-05-19 19:26
What are nucleotides?
Molecules that consist of a five-carbon sugar, a phosphate group and a nitrogenous base
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What are the polymers of nucelotides?
Nucleic acids DNA and RNA. DNA the pentose sugar is deoxyribose, whereas in RNA the pentose sugar is ribose
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What are the uses of phosphorylates nucleotides?
Nucleotides with more than one phosphate are phosphorylates e.g ADP and ATP. ATP is energy rich and used to drive most metabolic processes in cells
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What coenzymes contain components of nucelotides?
Adenine nucelotides are components of coenzyme NADP, used in photosynthesis, as well as NAD, FAD and Coenzyme A that are used in respiration
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Describe the structure of DNA
Polymer of monomers nucleotides. Contains of two polynucleotide strands that run antiparallel. Each nucleotide contains a deoxyribose sugar, phosphate group and a nitrogenous base. Phosphodiester bonds between nucleotides and hydrogen bonds bases
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Describe the importance of hydrogen bonding in DNA?
Adenine bonds to thymine with two hydrogen bonds, guanine bonds with cytosine with three. Allows molecule to twist into double helix, giving stability.
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How is DNA arranged in Eukaryotic cells?
Genome is held in nucleus and each molecule of DNA is tighly wound around histone proteins into chromosomes. Each chromosome is one molecule of DNA. Loops of DNA, without histone proteins, are found inside mitochondria and chloroplasts
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How is DNA arranged in Prokaryotic cells?
DNA exists as a loop within cytoplasm, not enclosed in nucleus. Not wound around histone proteins, and is described as naked.
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How does DNA replicate?
Via semi conservative replication
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Describe how the double helix separates in semi-conservative replication?
The DNA molecule unwinds, catalysed by a gyrase enzyme. The molecule then unzips, the hydrogen bonds between the nucleotide bases are broken. This is catalysed by DNA helicase, and results in two strands of DNA with exposed nucleotide bases
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Describe how two separate strands are synthesised in semi-conservative replication
DNA polymerase catalyses addition of new nucleotide bases in 3' to 5' direction, to template strands. Leading strand synthesied continuously, lagging in fragments. Hydrolysis of activated nucleotides supplies energy for forming phosphodiester bonds.
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In what ways is RNA different from DNA
Sugar molecule is ribose, has pyrimidine base uracil instead of thymine, polynucelotide is single stranded, chain is shorter, three forms mRNA, tRNA and rRNA.
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What is a gene?
A specific length that contains a code that determines the sequence of amino acids in a particular polypeptide or protein
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What is transcription and translation and why does it happen
Chromosomes cannot pass out of nucleus, so each gene has to be copied into a length of RNA (transcription) and then it can then pass out of nucleus as codons which are translated into a polypeptide at a ribosome
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What is the nature of the genetic code?
Near universal (in almost all living things, the same bases code for the same amino acids). Degenerate (for near all amino acids, there is more than one base triplet). Non-overlapping (read in threes starting at one fixed point)
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Describe the process of Transcription
A gene unwinds and unzips. Hydrogen bonds between complementary bases break. RNA polymerase catalyses formation of temporary H bonds with unpaired bases on template strand. Length of RNA produced is coding strand, can pass out of nucleus.
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Describe the process of Translation
tRNA molecules bring amino acids and finds place when anticodon forms temporary H bonds to complemenary codon on mRNA molecule. Peptide bond forms between adjacent amino acids. ATP required. AA sequence determined by gene
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Other cards in this set

Card 2

Front

What are the polymers of nucelotides?

Back

Nucleic acids DNA and RNA. DNA the pentose sugar is deoxyribose, whereas in RNA the pentose sugar is ribose

Card 3

Front

What are the uses of phosphorylates nucleotides?

Back

Preview of the front of card 3

Card 4

Front

What coenzymes contain components of nucelotides?

Back

Preview of the front of card 4

Card 5

Front

Describe the structure of DNA

Back

Preview of the front of card 5
View more cards

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